Hello everyone... Let's try and keep this thread only related to performance mods to the 4.9

I know there are differnt chips... super chips has one for $250 that says it adds 18hp and 28ft. lbs. tourqe, and fast chips has one for $160 that claims 13-15hp.... which is better?

besides exhaust, what else is there? any cold air intake? not too much parts though, or so it seems (hopefully with the bigger crowd putting 4.9's in Feiros, someone will make something) but without tearing down the engine, and completly reworking it, is there anything that could be done?

I am really interested in those chips though, as they are (considerably) cheap, and seem to add a nice amount of power, but which is better?

Personally, I'm skeptical of the claims of chipmakers. Other than raising the speed limiter, I don't believe the claims are accurate unless you're willing to sacrifice driveability, longevity or emissions.

For what reason (other than those above) would Cadillac detune their engines? Also, keep in mind that the 4.x engines don't have knock sensors, so detonation (and its associated damage) is a real possibility.

From what I've heard, you can accomplish just about anything a chip would do by running premium unleaded exclusively (and the same brand at all times for consistency) then manually advancing the base timing (by loosening and rotating the distributor) a couple of degrees. However, you're sacrificing reliability if you go on a long trip or get a bad tank of gas if it starts pinging and if you travel where environmental conditions are different enough from where you set the timing, you could have issues.

There's very little "tune-ability" in the efi systems on these vehicles. They are speed-density, which means they rely heavily on the physical dimensions of the engine in their EFI calculations. Yes, they adapt for temperature and outside air pressure, and they will fine-tune the mixture via the o2 sensor(s), however there's little you can do to get really serious change in output unless you can get inside that chip and customize the mappings to suit your situation. If you can do that, you open the door to a huge amount of possibilities.

You can make slight adjustments to the fuel pressure by replacing or altering the regulator. You could also make sure the TPS is adjusted properly and get some new injectors, but that's really about it and the increase would be negligible

One other alternative would be to run an aftermarket EFI system. Though not cheap, you could then build off that base and go in all sorts of directions - up to the limit of the transaxle, which is a whole 'nuther issue...

Of course, getting your body computer to talk to an aftermarket ecm/pcm is even less do-able than reprogramming the original ECM, so you'd need some sort of piggyback arrangement (or a hack) to get your onboard systems to function, and forget the onboard diagnostics altogether.

You could also hack in another, more tuneable GM ECM (like that out of the V8 truck and/or Camaro/Fbird). There are quite a few guys burning chips for that ECM. Same issues with interoperability as the aftermarket. but its a cheaper way to go.

If you decide to go down this route (performance mods), one good investment would be one of those G-tech meters. "Seat of the pants" performance evaluation is less than useless. You need hard numbers and the best (and safest) place to get them is at the track.

I don't mean any of this as discouragement, and I'd love to be proven wrong by some hard before/after numbers. This is more of a summary of my investigation of what it would take to go down this same path. Don't fall into the ricer trap of believing that just because it "looks fast" that it is fast. Do your homework and get some empirical data to evaluate the results.

hmmm..... so basically your saying there is not much that can be done?

I was thinking, get that computer chip, try out a custom CAI, and after the car is paid off, get a nice cat-back Flow Master dual exhaust with medium diameter chrome tips (1 on each side in the back) that will look nice, and give the V8 the growl it needs..... I am thinking between those things, I may get like 30-35hp?

I was also thinking along the lines of a high performance cam, or rocker arms etc... I guess the only other thing would be to have a machine shop custom build it up....

.... then again a '93 DeVille isn't really the car to hot rod out..... I want to get 3 cars in my life (fun cars, not dailey drivers) 1 is a '70 Chevelle SS (mmmmmm 454) other is a late 70's DeVille with the 500 (make a huge sleeper outta it, just crazy) and the last would be a Grand National.

If you think that no performance gains can be found strictly through ECM/PCM tuning, you have a lot to learn sir. True, some of the things you'll do MAY compromise the MPG but that's about it. The emissions will be Ok and driveability can actually be improved upon a lot. At the risk of repeating myself, I would suggest talking to Ed Wright at FastChip and he WILL set you straight on what CAN and CAN'T be done with your ECM.

Well, I am saying kinda simple things...... reprograming the ECU seems like it is very time consuming, costs alotta money, requires gear I don't have, and very hard to come by. I am not saying it can't be done, I am just saying, as I was reading it, it seemed very difficult.

I didn't say that ECM tuning was completely ineffective. I said you could accomplish the same thing by raising the base timing. A generic one-size-fits-all 4.9 chip is not going to do much more for you. If its custom-calibrated for specific modifications you've made, that's a different story.

Here's what I base my ECM comment on, as well as a good part of the rest of my comments. These are posts from a GM Powertrain engineer who frequents the Allantenet board. He was involved in the Allante and 4.1/4.5/4.9 engines as well as Northstar development. (Sorry, its a long post) Chips and performance mods have been a topic several times. 4.1 and 4.5 engines are essentially the same as 4.9s:

http://66.216.15.167/cgi-bin/yabb/YaBB.cgi?board=talk;action=display;num=1038585041; start=8
(This particular thread is about one of those "20+ hp chips on e-bay, but the discussion wanders into ECM chips in general"

"For the record...."chips" don't make power...more airflow thru the engine makes more power and the computer calibration cannot create more airflow (unless you have a turbo-charged engine and the computer is limiting boost....and/or you have a diesel....but that's another story)

If the engine has been modified with cam, heads, intake, etc....then the computer calibration will need to be modified to account for the increased airflow but the hardware mods are what is responsible for the power increase....not the calibration mods.

While there may be some engines some where that are not calibrated for the optimum performance at WOT I would say that the vast majority of them are. There is no emission nor government constraint on the fuel and spark delivered at full throttle so there is no reason, especially on a performance car engine, for the manufacturer to "hold back" on the power.

I can positively state for a fact that the Northstar engine is calibrated for maximum pwer with the factory calibration and there is no way on earth a "chip" is going to make more power. Adding or subtracting fuel or spark is not going to do anything but slow it down.

The 4.1 and 4.5 engines are just a trifle "soft" on the spark calibration to account for the fact that the engines did not have a knock sensor but no chip change is required to compensate for this. Just set the timing at the distributor up 2 or 3 degrees and run good gas and you are all set. Send the $5.00 to your favorite charity.

The item advertised on e-bay is a joke. It is just a simple resister to replace the Inlet Air Temp (IAT) or Manifold Air Temp (MAT) sensor. This will accomplish nothing except screw up the fuel calibration and make the engine drive poorly on coldstarts as it will no longer have active MAT compensation. This is an old trick that has been used for many years on a variety of fuel injection systems as a means of altering the fuel delivery curve for various reasons.

It is possible for a specific set of modifications to the engine to use the MAT substitution as a means of compensation and, in fact, it works quite well to put a variable resistance pot in place of the MAT if you are using the car for drag racing or some limited driveability use with a heavily modified engine but for an engine driven daily with no other mods the idea of gaining power by putting a resister in place of the MAT is ludicrous.

I don't think there are as many "compromises" in the factory ECM calibrations as some might imagine when the engine is operating at WOT. Many of the "chips" will turn off the knock control, for example, and then tell you you have to use only high octane gas.but you would get the same result if you used the high octane fuel with the factory calibration....to prevent detonation so the knock control system wouldn't have to retard the spark to protect the engine. The good gas is what made the power, not the "chip" that now compromises the protection of the engine. Another trick is to turn off the EGR....but the factory calibration turns off the EGR at WOT anyway. The chip without EGR will "feel" better at part throttle...but who cares about part throttle power...you are throttling the engine anyway. If you hold the throttle wide open the EGR will be disabled with the factory "chip" for free. Another trick is to delay the apply of the TCC....once again, makes the car feel better at part throttle...but, once again, the factory cal does that at WOT anyway. AC causing Hp loss, chip gets rid of it...???...the facotry cal turns off the AC compressor at WOT automatically for a short period of time so there is no need for this mod. The list goes on and on...and....there is no way the aftermarket "chips" are going to make more power.

One feature of the Northstar engine is the fact that the factory calibration runs at the optimum fueling level (actually on the rich limit of optimum) for about 30 seconds and then the calibration goes richer for protection of the piston crowns (temp) , to prevent the spark plug tips from getting too hot and inducing preignition and to protect the catalytic converter from overheating. If the engine is run at a sustained full throttle condition in about 5 minutes it will get rich enough to actually loose about 2-3 percent torque.... This feature could be eliminated in a "chip" to limit the torque loss at sustained full throttle but, you'll be buying pistons later if you run it at sustained full throttle.

This will cause some controversy, I'm sure, but the fact is that the chips sold to improve the performance of the engines rarely if ever do anything but compromise the driveability , emissions and engine protection. "

http://66.216.15.167/cgi-bin/yabb/YaBB.cgi?board=talk;action=display;num=1034121952; start=1
(This thread is specifically about an '89 with a 4.5)

"The 4.5 engine is like any other engine and will respond to the same modifications....unfortunately there are two obstacles....one is that there are little or no aftermarket parts available for the 4.5 engine....and, two, the engine has a speed density fuel injection system that does not react favorably to things that change the airflow thru the engine....and you must get more airflow to make more power.

Some simple things that help a little without seriously affecting the fuel injection calibration....

Get the exhaust backpressure down...go to a low restriction muffler/larger pipes/dual exhaust from the catconv back/etc.

Bump the ignition timing up several degrees. The 4.5 does not have a knock sensor so the spark calibration is on the conservative side to avoid serious damage to the engine if less than good fuel is used. If you always use premium or better the engine can benefit from an extra 3 or 4 degrees of spark. Just bump it up and drive. If you hear detonation or pinging then back it down a degree until the detonation is gone. Tune it to "top dead ping" as we laughingly call it. Nothing will be hurt if yo are reasonably carefull and use good fuel. Just always listen for detonation if yo buy unknown fuel.

Bumping up the timing is as easy as just resetting the distributor timing with a timing light.

If you really want to take the engine apart you can get the lower intake manifold and/or cylinder head ports ExtrudeHoned to smooth the surface finish and increase flow.

If the heads are off you can deck the heads about 1 mm to get more compression.

Other than having a custom cam ground or other special parts made this is the easy stuff.

If you can find someone who can reprogram the ECM chip you can find a 4.9 and plug the parts from the 4.9 into your block and have a 4.9 litre displacement instead of the 4.5 ..... nothing beats cubic inches. If you did do the 4.9 conversion (which mechanically is very doable) it will run poorly unless the ECM is reprogrammed ot recognize the extra displacement ....or....you could do a crude compensation by going to an adjustable fuel pressure regulator and bumping the pressure up 9 percent to roughly equal the 9 percent displacement increase."

and

"Leave the catcon in place and do the Borla or Corsa cat-back system. The cat does not hurt the power at all with an exhaust system installed.

Bump the ignition timing up a few degrees and leave the ignition system alone.

The air induction system on your engine has plenty of capacity for anything you're going to do.

Forget the chip. The factory chip has the correct fuel and spark values for maximum power. The only "soft spot" in the production chip is the spark calibration as I mentioned...it is a few degrees short of max power to give some cushion for poor fuel. You can correct this with bumping the timing up and making sure you always have good fuel. An aftermarket "performance chip" would do the same thing and require you to run good fuel anyway so just bump the timing up and save yourself some money."

While I agree with most of what was said in that other thread about the use of ECM/PCM mods to attain better performance, I would add the following points that were overlooked:

1. Doing ECM/PCM mods may net minimal WOT performance gains but the part-throttle driveability is where the HUGE difference can be attained.
2. ALL fuel programs that I have seen are a little fat from the OEM and there is some room for improvement that CAN be made (and verified) through the use of wide-band O2's and a dyno.
3. Even though the spark and fuel tables in the program are pretty good from the factory, the trans shift tables are generally quite able to yield big gains in both overall driveability and 0-60 times as well as 1/4 E/T's.

Kevin,

Have you actually experienced this on a 4.x engine/transaxle? I'm not doubting you, but I find it hard to believe you can make changes to that drivetrain with a chip that come anywhere near justifying $160, much less $250. What is the driveability difference?

I'm just wondering what a chip can possibly do that would exceed the stock setup when its properly tuned. A lot of the power is already wasted because you can already easily overwhelm the traction of the drivetrain (either with wheelspin or with the TCS intervening), any attempts to launch harder just transfer the weight off the front wheels. If you bump up the timing, you risk uncontrolled detonation. If you lean out the fuel, you can make things really bad. Airflow is pretty much fixed.

I guess I don't really question that changes are possible with a chip, as much as I question that a chip that can be dropped into a stock vehicle, or one without very specific modifications, can really deliver anything of value, or anything that can't be accomplished with some minor adjustments outside of the ECM.

Also, a 4.9 is already putting more torque through the 440t4 or 4t60 than any other GM engine it was attached to. I'm not sure playing with the shifting without beefing things up is wise, but that's just a hunch on my part.

Anyhow, I hope this doesn't come across as skepticism, its intended to be inquisitive.

I have limited seat time on the 4.x stuff to be honest. The lion's share of my time has been on the LT1-powered stuff and some of the Northstar stuff. Overall, the theory is sound and quite reasonable to relate to virtually all engine management systems.
You're right that there's not as much that can be done with ECM's as can be done with PCM's (drop-in chip vs. re-flash), but that's why I suggested Ed Wright as an information source. He has FAR more experience than I and can DEFINATELY describe what can and can't be done on a particular system.
Even if you didn't do anything to the spark and fuel tables, you can still get a great improvement in driveability from playing with the trans tables.
I personally got a MUCH more enjoyable car to drive and one that accelerates better as evidenced by my time slips at the track. Each time I went down, I had a new flash to try and all but once netted an improvement in my E/T's.
Downshift/upshift points, shift firmness, converter lock-up points. All these are places where the OEM program is lacking for the performance minded driver. Remember, these cars weren't really setup for performance, they were setup for SMOOTH cruising, and the best MPG they could get.
As for your point about off the line traction, you're absolutely right but the modifications I suggest in the programming would have little or no effect on that.
Perfect example would be; on my car, I bumped the 2-3 shift up a little and kept the converter off until 50mph on my first or second flash and it made a big difference in both E/T at the track and driveability around town. I've since played with other stuff but you get the idea. You can realy custom tailor the trans "personality" to your driving style and that makes a huge difference in the satisfaction factor while driving.
As for the torque to the transaxle issue, I wouldn't be concerned to much unless you start doing part swaps on the car and start REALLY increasing the engine output. I don't agree that you can't make power with just a reprogram of the engine management system but, I do agree that you won't make much. The trans work has nothing to do with power increases, but everything to do with what you do with the power.

man i missed this place, i kinda gave up on my deVille after the hit and run, BUT i have a new found love for it, so she'll be getting fixed soon. anyway, i dont know much about the EFI system on the 4.xs, but say if you bumped up the displacement from, like 4.5 to 5.0 couldnt a chip help compansate and tell the ECM to send more fuel? oh and what about after the heads and intake beign ported and the exust, could the chip help with that too?

Hello everyone... Let's try and keep this thread only related to performance mods to the 4.9

I know there are differnt chips... super chips has one for $250 that says it adds 18hp and 28ft. lbs. tourqe, and fast chips has one for $160 that claims 13-15hp.... which is better?

besides exhaust, what else is there? any cold air intake? not too much parts though, or so it seems (hopefully with the bigger crowd putting 4.9's in Feiros, someone will make something) but without tearing down the engine, and completly reworking it, is there anything that could be done?

I am really interested in those chips though, as they are (considerably) cheap, and seem to add a nice amount of power, but which is better?

I've been giving this some thought, and it seems to me that the most bang for the buck would be a mild nitrous system. It wouldn't be an "out of the box" setup, but you'd see the largest gains for the least money. Of course, you could overwhelm the transaxle.

I'm particularly thinking of the PFI or TPI (Allante) engines. One of the nitrous companies makes a setup for 5.0 mustangs where you insert a fuel/nitrous injector below your stock injector (the stock injector is placed inside the nitrous/fuel injector). It raises the fuel rails up a bit, but that probably isn't a problem. These systems only work at WOT, so you're not limited by the ECM. Also, since the nitrous system has fuel as well, you don't have to worry about going to lean. If memory serves, they have a way to retard the timing, or you retard it all the time, I can't remember.

I don't know if I'd try nitrous with a throttle body 4.9, unless I was plumbing in individual fuel/nitrous injectors.

I can't say for sure it would work, but it might be worth looking into if you're serious about getting more power. Additionally, with the nitrous systems you can usually tune them for the amount of boost you want, so you only have to buy the system once, then as you make upgrades (to the transaxle!) you can increase the nitrous shot.

Here's NOS's piggyback system http://www.holley.com/HiOctn/ProdLine/Products/NOS/NOSNS/NOSzle.html

From that page:

"Horsepower levels up to 150HP are possible with stock fuel systems and internal engine components. Higher levels require upgrades such as forged pistons and stand alone fuel systems. "

I did a quick search and found a company that carries the universal V8 system. It's around $1600.

http://www.seffects.com/catalog/product.asp?ProductCode=NOS08008&MainCategory=Nitrous%20Oxide&Category=Nitrous%20Oxide

Something to think about.

Panther,
If you want a FAST Caddy you need to buy a Road Rocket like Katshot drives with the Chevy LT1 RWD, Then you will have the Best of both worlds >Luxury and Performance All in One car! :spin: :spin:

I'll go for that :sneaky:

no, I am not going to put NOS or any nitrus....not in this car.

I know a car witht he LT1 and RWD would be awesome, but I don't have that, and just thinking of ways to get better performance from what I do have.

Whatever path you choose with your car, just realize that the stock engine/transaxle package WILL NOT handle a significant power increase without SERIOUSLY shortening it's service life. At least the LT1 in stock trim has the basic ability to be a solid foundation for a performance car whereas the Cadillac V8's do not.

Whatever path you choose with your car, just realize that the stock engine/transaxle package WILL NOT handle a significant power increase without SERIOUSLY shortening it's service life. At least the LT1 in stock trim has the basic ability to be a solid foundation for a performance car whereas the Cadillac V8's do not.

Well, that would be differnt if there were actually performance parts out for the 4.x

That's what I made this thread for, trying to find any sort of performance ideas and differnt things to boost power....but anything that anyone finds will just be alittle bit and not a whole bunch.

if there were as many performance parts for the 4.9 as is the LT1, then yeah, I would start thinking about other components, but there isn't too much.

so what about using a chip to tell the computer to send more fuel say after porting your heads or bumping up the displacement?

Can anyone PLEASE describe exactly where the PCV valve is on the 4.9, I need to change it before winter this year! I cannot find it and I have examined both the intake manifold and the valve covers.

look at your distributer and follow your ignition wires to the valve cover toward the fron of the car, it should be right next to the wires on your left(your facing the engine) and across from the dipstick(on your right). If you still cant find it i'll see if i can scan the pic. oh and it plugs into the valve cover.

look at your distributer and follow your ignition wires to the valve cover toward the fron of the car, it should be right next to the wires on your left(your facing the engine) and across from the dipstick(on your right). If you still cant find it i'll see if i can scan the pic. oh and it plugs into the valve cover.

I tried telling Ralph that over a month ago. Maybe he'll find it by winter :rolleyes:

OK, I got my Maglite and looked, I followed the wires, etc. If it is between the dipstick and the left sied of the valve cover, IT MUST be under the plastic covering?! I looked at an angle with the light and all I see are a fuel rail and a lot of injectors. This weekend I will take the black plastic off, as only one bolt seems to hold it on, and see what's under. The pcv seems hard to find because it is under a hose inside the valve cover, right?! :helpless:

yeah, OHHHH you have the cover that hides the injectors and fuel rail, no wonder you couldnt see it. Take that off and i bet you'll find it in no time. I dont have that on my engine.

I FOUND IT!! :lightbulb Thanks for your info guys. It was on the far right side of the front valve cover once you take the plastic off. :banghead2

Well, I am saying kinda simple things...... reprograming the ECU seems like it is very time consuming, costs alotta money, requires gear I don't have, and very hard to come by. I am not saying it can't be done, I am just saying, as I was reading it, it seemed very difficult.
your best bet would be aK&N filter,new feul reg.and free-flow cats&muffler.anything more will murder your transmission. i've got the same car you do and they're pretty darn fast already,till the tranny starts slipping from all the hotrodding!

I have gotten the superchip for my cadillac with the 4.9L engine. It had some problems with it so I had to send it back to get a new one but it had a noticable difference. It took a good second off of my quarter mile time. I also have many mods done to my engine. I have a 4.9L engine which normally comes with 16 valves, but mine has 32 valves, just like the northstar. My engine came with this stock, it was a prototype engine built by Cadillac in the late quarters of 1992. Only, i think, 2000 or so were made with the 4.9L 'Northstar'. I also have a Port and Polish done on my heads and i have a performance cam in it. I dont know where to buy these though because the previous owner had put them in. I am looking into mufflers and flowmaster seems like the best option right now. The problem with my chip is that ill put it in, and it will work great, then i turn the car off and when I start it back up, the service engine soon light comes on and my car has absoultly no power at all. It feels like it goes into second gear and then wont shift out. So i put the stock computer chip back in and start the car again, give it a second and the service engine light goes off and the car is fine again. I can put the chip in again and it will work fine until i turn off my car, so i am sending it back to superchips to get it looked at. My car is the 1992 STS and it runs 14.8 in the 1/4 mile. Its 0-60 is somewhere around 5.5s.

I have gotten the superchip for my cadillac with the 4.9L engine. It had some problems with it so I had to send it back to get a new one but it had a noticable difference. It took a good second off of my quarter mile time. I also have many mods done to my engine. I have a 4.9L engine which normally comes with 16 valves, but mine has 32 valves, just like the northstar. My engine came with this stock, it was a prototype engine built by Cadillac in the late quarters of 1992. Only, i think, 2000 or so were made with the 4.9L 'Northstar'. I also have a Port and Polish done on my heads and i have a performance cam in it. I dont know where to buy these though because the previous owner had put them in. I am looking into mufflers and flowmaster seems like the best option right now. The problem with my chip is that ill put it in, and it will work great, then i turn the car off and when I start it back up, the service engine soon light comes on and my car has absoultly no power at all. It feels like it goes into second gear and then wont shift out. So i put the stock computer chip back in and start the car again, give it a second and the service engine light goes off and the car is fine again. I can put the chip in again and it will work fine until i turn off my car, so i am sending it back to superchips to get it looked at. My car is the 1992 STS and it runs 14.8 in the 1/4 mile. Its 0-60 is somewhere around 5.5s.

Do you have any pics of this engine? I've been on a lot of boards discussing the 4.x engines and never heard of such a thing. Are you able to get it to pass emissions? Did it use northstar heads or some other design?

The 4.x (non-Northstar) blocks fit pretty tight against the framerails on the front end. Its difficult to visualize where they would have run the cam chains without seriously reconfiguring the block, although I guess anything's possible with enough time and money.

Its doubtful any standard 4.9 chip is going to work with a 32 valve engine. The breathing would be totally different. Was your chip configured to the specifications of your engine? Where are you going to get parts for it when they wear out, or were stock Northstar parts used?

Do you have any pics of this engine? I've been on a lot of boards discussing the 4.x engines and never heard of such a thing. Are you able to get it to pass emissions? Did it use northstar heads or some other design?

The 4.x (non-Northstar) blocks fit pretty tight against the framerails on the front end. Its difficult to visualize where they would have run the cam chains without seriously reconfiguring the block, although I guess anything's possible with enough time and money.

Its doubtful any standard 4.9 chip is going to work with a 32 valve engine. The breathing would be totally different. Was your chip configured to the specifications of your engine? Where are you going to get parts for it when they wear out, or were stock Northstar parts used?

The engine looks quite stock, i was quite doubtful myself, then i got it checked out by my mechanic and it defenatly has the 32 valves like a northstar. I told the guy at the place where i ordered my chip that it has 32 valves and he said that it wouldnt matter how many valves it has or anything like that, just had to know the size of the engine. That is the 4.9L so i ordered that chip. Parts is a big problem to deal with, i have looked all over for this type of engine and i cant find anything on the internet. My mechanic has heard of this engine and he told me of this and explained everything to me on the 32 valves. Stock northstar parts really cant be used because of the fact that it is a 4.6L it has Dual-Over Head Cams and its Multi-port fuel injection. Most of the parts needed can be used from a stock 4.9L, things like the water pump and the power-steering pump, and idle-tensioner pulleys and all of the such. I also didnt think it was much of a northstar, but it is a lot faster then any other 4.9L.

it must have a fork type rocker arm to actuate 4 valves per cyalnder , the valves covers should look quite a bit diffrent , it would also require the plugs to be moved from there current location in the head to a more "hemi" type postion

what tranny does it have ? couldnt be the 4t65e as it wouldnt take the powerband of a 4 valve 4.9 which should make in the neiborhood of 255 hp and 300+ lb feet of torque

its odd a customer would have gotten hold of such a car , only thing i can figure was caddy felt northstar wasnt ready yet and needed to test the rest of the northstar system so when the engine was ready it could go right into production , all of those cars should have been test mules , and crushed later on

sounds like a cool engine , i want pics , so i can keep my eye out in the junkyard for it

I dunno, soulnds strange to me..... the 4.9 and N* are 2 completly differnt engines...it really isn't like you can turn a pushrod into a DOHC overnight.....

no i think he said the n* is diffrent from his due to the overhead cams so its still pushrod

i belive the chevy porcupine head V8 int he mid 60s was a 32 valve pushrod v8 , it seems thats how it got its name

and 4 valves per cylander on a pushrod engine is nothing new detroit diesel has been doing that for 40 years on its 2 strokes, even the injectors on detroits ran off of a pushrod/rocker arm

Something this rare has to be worth something to somebody! I would have left it as original and untouched as possible, because if you want special distinction, or collector resale value, original=big bucks!!

Or maybe its just a regular 4.9 and the kid got ripped off. Sure looks pretty normal


http://www.cadillacforums.com/forums/showthread.php?t=4400&page=2

Hey whats up, my name is Kevin, I am 17 and I work at McDonalds.

It's a nice car, I saw the pics. The 4.9 isn't anything to be ashamed of, either. This sounds like one of those cases where if somebody tells the same lie three or four times, they start to believe it themselves.

That's a real shame.

why would cadillac even bother with this engine, the N* is derived from the Aurora not the 4.9....believing this is madness i tell you

Maybe we should make him a "4.9L NORTHSTAR" sticker to put on that bad boy? Then people would believe it!

Actually the NorthStar came from the Quad4 4banger from the late 80's which has absolutly nothing to do with the 4.9 at all......

...... looks to me like someone took off the 32v NorthStar badge and stuck it on that car, then when selling it said, Hey, look at this, see how it says 32v NorthStar on the back? but the enigne says 4.9L? well, this is a special 4.9l 32v Northstar.....

only a sucker would go for it.... other wise, it is pretty much imposiible for the 4.9 to have 32v

yup standard 4.9 , no way 16 valves on each bank of cylanders would fit under those valve covers , tried to be open minded about the kid and thought "maybe" it was true...oh well

well, ther is ONE possibility.. i have seen aftermarket kits to turn regular 350 SBCs into a 32 valve setup, and its still OHV pushrod...perhaps soemone had a custom 32 valve set of head put on.. for shits and giggles.. heheheh..
either way, the ONLy way to tell is if this jackass wants to tear off the top of his engine and take pics..



yup standard 4.9 , no way 16 valves on each bank of cylanders would fit under those valve covers , tried to be open minded about the kid and thought "maybe" it was true...oh well

We already know it's not what he says.... But this is a good thread, I'm doing injectors and a camaro-style exhaust in the next week and I'll post how it goes. We need to find a better aftermarket for these cars, any ideas other that chip/ignition/injectors/exhaust/thermostat/air filter?

I just finished! 8 Accel Performance injectors (19 lb/hr) and a Walker Sound FX muffler / tail pipes for a 87 305 H.O. Camaro. Sounds wicked! I burned em through most of first gear test driving it. What kind of experiance have people had with the fastchips chip?
Thanks,
D.

Hey rick, whats with you making posts that arnt 1.2 gb long :bonkers:
On here your posts are short and sweet.

Hey guys i'm new to this whole thing but I'm wondering if a cheap, effective addition would be one of those turbo air twister things like a Cyclone. Supposedly they act like Ram Air for any car. It must improve the airflow a little bit but i'm not sure if it's enough to notice. Anyway just thought i'd throw my input in. I think they Cyclone goes for around $60, so if it works then it might be worth it.

use that money to get a couple "type R" stickers or some cool lighted racing pedals... they'll give you about the same amount of performance. plus, I don't know if they'll fit the caddy...?

Hey guys i'm new to this whole thing but I'm wondering if a cheap, effective addition would be one of those turbo air twister things like a Cyclone. Supposedly they act like Ram Air for any car. It must improve the airflow a little bit but i'm not sure if it's enough to notice. Anyway just thought i'd throw my input in. I think they Cyclone goes for around $60, so if it works then it might be worth it.

they only help the engine at Wide Open Throttle. so it's a marketing gimmick. don't waste your money or time with that crap.
you want to make more air flow make a totally custom air intake like i am soon.

I have been really thinking about the intake system on the 4.9, I heard it is pretty free-flowing, and from the looks, it is... the only thing is, when the air first enters the system, the tube gets really small before the airbox, then at the air box and after that it really opens up.... now there are 2 things I was thinking of:

1) it is designed to be "restricive" for whatever performance/sound reasons they had

2) Bernolis (sp) principle... increase in velocity = decrease in pressure, and by having the hose there "pinch" together, it may definitly apply to that.....

.... I have been thinking about what to do, it would be very easy to get a cold air intake or something, but I really like the look of the factory intake system/airbox with the 4.9 sticker..... now I have been thinking about getting an air box form a junkyard (since I don't want to start hacking my nice one up) and maybe cutting out the bottom, and have the intake air reloacted, or maybe have 2 locations for air to come in..... that just seems really restictive to me, and I think that if it was opened up, it could be made to flow better...... but if more air went into the engine, would the ECM add more fuel, and therefore get more power, or try to adversly compensate for it (thinking something is wrong) and maybe loose power?

Another thing, being that the 4.9 has the old school Throttle Body setup, in which it is on the top of the intake manifold, like where a carbuator would be, there are alot of possibilites if someone wanted to get createve, hack up the hood a little (which I am not doing) maybe even going extreme and adding a blower (oh man that would be sweet) but that can also aid in doing things with the intake....

were those 19lb Accel fuel injectors worth the money? big differnce over the stock injectors?

Also, I am gonna be replacing the plugs/wires once I get her back on the road.... she has 87k miles on her now and the car has AC Delco platnium plugs that are supposed to last 100k miles..... should I get them replaced with AC Platniums, or use NGK or Bosch +4 (which I heard some good things about and quite a bit of bad things) and AFA wires, I want to get nice high performance wires.... or should I go with the regular AC Delco? What about the dist. cap and rotor?

see, I want to get the best plugs/wires/cap+rotor as I can, since there aren't many performance parts for the engine as it is, so if I have any chance to get something that may improve the performance, even slightly, and I am going to be doing the work already, I want to go with the best.

I have been really thinking about the intake system on the 4.9, I heard it is pretty free-flowing, and from the looks, it is... the only thing is, when the air first enters the system, the tube gets really small before the airbox, then at the air box and after that it really opens up.... now there are 2 things I was thinking of:

1) it is designed to be "restricive" for whatever performance/sound reasons they had

2) Bernolis (sp) principle... increase in velocity = decrease in pressure, and by having the hose there "pinch" together, it may definitly apply to that.....

.... I have been thinking about what to do, it would be very easy to get a cold air intake or something, but I really like the look of the factory intake system/airbox with the 4.9 sticker..... now I have been thinking about getting an air box form a junkyard (since I don't want to start hacking my nice one up) and maybe cutting out the bottom, and have the intake air reloacted, or maybe have 2 locations for air to come in..... that just seems really restictive to me, and I think that if it was opened up, it could be made to flow better...... but if more air went into the engine, would the ECM add more fuel, and therefore get more power, or try to adversly compensate for it (thinking something is wrong) and maybe loose power?

Another thing, being that the 4.9 has the old school Throttle Body setup, in which it is on the top of the intake manifold, like where a carbuator would be, there are alot of possibilites if someone wanted to get createve, hack up the hood a little (which I am not doing) maybe even going extreme and adding a blower (oh man that would be sweet) but that can also aid in doing things with the intake....

were those 19lb Accel fuel injectors worth the money? big differnce over the stock injectors?

Also, I am gonna be replacing the plugs/wires once I get her back on the road.... she has 87k miles on her now and the car has AC Delco platnium plugs that are supposed to last 100k miles..... should I get them replaced with AC Platniums, or use NGK or Bosch +4 (which I heard some good things about and quite a bit of bad things) and AFA wires, I want to get nice high performance wires.... or should I go with the regular AC Delco? What about the dist. cap and rotor?

see, I want to get the best plugs/wires/cap+rotor as I can, since there aren't many performance parts for the engine as it is, so if I have any chance to get something that may improve the performance, even slightly, and I am going to be doing the work already, I want to go with the best.

in regards to the intake designing i have figured out a very easy way to create a very simple and cool looking cold air intake for our engines. i am currently waiting for some more money to come in so i can buy the parts need for this project, i kind don't know if it's going to work (90% sure it will but) meaning i don't know if i can make it so i can connect all the hose that are on the stock intake, my 4.5 has 3 connections ,4.9 have two. i will keep updating the progress of this project. and nightwolf if you want to know how much it's going to cost i figure that out as well and the total would be about 300 bucks give or take a few bucks.as to how much more flow and hp it will produce, i'm going to guess my 10-12 hp on my design that is, and a super freakin cool sucking sound! remember these engines are very potential.:)

sweet.....let me know, I was thinking something the same, keeping everything stock, but moddin ghte bottom of the airbox so re-route the intake air.... It will definitly be nice to check out.... what makes you say that these engines have alot of potential? (there is pretty much 0 aftermarket for them)

I'm with you knightwolf... hack up the stock intake a little bit. hack a couple holes in the bottom, run some dryer hose up to the air dam or grill. betchya i couple do it for like $20. how about you try it first, then post some pics... better yet, hack up your hood and do something cool (imagine a 3" cowl on a lac! that'd be sweet!!), and post pics... lol

sweet.....let me know, I was thinking something the same, keeping everything stock, but moddin ghte bottom of the airbox so re-route the intake air.... It will definitly be nice to check out.... what makes you say that these engines have alot of potential? (there is pretty much 0 aftermarket for them)

i mean that these engines have alot of power that wants out and one of the easiest things to do is create more airflow and less backflow of the exhaust, doing this will make the engine breathe alot better,also if someone was really wanting to get more out of the car, lightweight pulleys would be a great project, this would free up some more hp.

Ok, My tranny just went historian, i just ordered a jasper reman'd T60E ($1872.00, 3yr/75k warranty).

Is there some performance pieces-parts, without sacrificing driveability, that i should think about adding while i am at it? The garage said that the jasper should handle anything and be pretty responsive even if i went with a light NOS kit downt he road.

Any thoughts?

i mean that these engines have alot of power that wants out and one of the easiest things to do is create more airflow and less backflow of the exhaust, doing this will make the engine breathe alot better,also if someone was really wanting to get more out of the car, lightweight pulleys would be a great project, this would free up some more hp.
i think sport compact car removed the lower half of the airbox on the 00 sentra 2.0 se , and made a gain . they removed the lower half and duct taped the whole assembly in the perpendiclar postion with the hood removed (ram air effect)

the whole car was later placed under the care of a sawzall , rear clip was removed along with the roof . basicly they wanted to break the car into the 14 sec barrier with spending no money . which they did after shaveing close to 1000 lbs off the car and makeing the car compelty illegal for any kind of use

we modified the air box in a 95 VW gti by drilling holes in the bottom of the lower airbox , not sure of the performace gains but it sounds like it will suck the front bumper thru the intake when one is really on the throttle , a very deep long burp sound

I dunno, I am not going to start hacking up the airbox on my car right now (it is in wayy too nice shape.... plstic isn't fadded or anything) maybe I can find one at a junkyard....

Yeah, about the engines.... just how much power would beter airflow do? I am going to be getting either a Flow Master, or Edlebrock muffler... but leaving the stock cat and 2.5" piping... is the 2.5" piping restricive? I mean, while it is a V8... in the world of V8's it is a small one....

There are shift kits for the 4T60E... my father just had the 4T65E in his '99GTP completly rebuilt and beefed up ($1,100)

Stonage... yeah, that was like a huge joke, I have the link saved somewhere... I tired to find it before, but I coudln't......

.... I was thinking like cuttin gthe bottom of the air box, to add a dryer hose as LacSeville said.... then just routing it somwhere behind the grille or another area.... gotta be careful about water/rain, but it will go into the stock airbox, which will then go through my K&N air filter and into the engine.... I am trying to think where I should route it, and where to come out with...... if this was done... is it ok to have 2 hoses going into the air box? will it damage anything? I'll have to check it out more...

nobody makes lightweight pullys for the enigne... there is nothing made... you would think that SOMEBODY would make something.... the 4.9 swap is becoming pretty popular in Fieros.....

Here's The link: http://forums.vwvortex.com/zerothread?id=776885

dear god... what a waste. oh well, if you've got money like that, then go for it. hmmm, i wonder what my roof+rag top weighs? 300lb? that'd shave off a tenth don't you think? just playing, but a drop top 91 seville would be pimp... :coolgleam

rather, no top seville

I've been hunting a 4.5L Caddy V-8 for a Fiero swap. Couple things I've learned along the way:

First, displacement is NOT everything. The 4.5 and the 4.9 share the same bore size. The 4.9 is just a "stroker". A longer stroke typically increases torque, which is good for the heavy caddys. I don't need 310 ft/lbs of torque in a 2500 lb car, what I need is HP. Sadly, the only way you will get HP out of the 4.x engines is with high rpm. There's a problem with this. The 4.x engines were never intended to be run in the 6000+ range, and do not have adequate airflow in or out.

The 4.9 is a very good engine for WOT drag racing, but has a higher rod angle, and is not an engine you want to rev to the 7200ish rpm where my fiero 3 speed trans will be shifting (modified for this shift point, they shift about 1000 lower stock).

I'm talking only about the 4.5L from here on out.

Getting air out is simple. First, the caddy exhaust manifolds are really worthless. They have to go. You need to buy a set of headers for a small block chevy, and cut them off at the plate that bolts them to the head. Have a machine shop make you a plate, and weld it on. Just bring them the headers and a pair of exhaust gaskets for your engine. From there, just use a pair of high flow aftermarket catcons, a crossover tube betweent the duals, and end it in a pair of 5 inch supertraps. Supertraps have a strange sound for a caddy, but you can't beat them for tunability.

Second, (little harder to do, but no parts need to be fabricated) 4.9L heads will bolt to a 4.5L engine, and they flow better, both in and out.

Finally, the caddy intake flows fine, but limits your cam choices. a simple extrude hone will make a world of difference here.

Cam's? No, of course there are no good aftermarket cams, right? Wrong my friend. Call up Lunati, they will grind whatever you want, and charge you off the rack price.

For my application, it's easier for me to use standalone systems than to try to make the caddy ECM perform in a car that weighs half as much. I will be tossing the ECM on a shelf, and using an MSD 6AL ignition, and a Holley Pro-jection 670 CFM 2bbl (intake manifold needs to be modified to use this injection).

My hope is to get 300+HP, and still have at least 200ft/lbs of torque. The 4.9 makes 210HP/310Torque stock.

http://pff.hostkansas.com/pffimages/My_baby.jpg

Nice to know about Lunati, I'll give them a call for my swap project. :coolgleam What are you doing for valvesprings and pushrods ?

Unfortunately on the header thing, I don't know of too many headers for a small block Chevy in a FWD GM..... but that's good info just the same.

Thanks. :thumbsup:

4.5= 180hp 245ft lbs of tourqe
4.9= 200hp 275ft lbs of tourqe

good luck getting any of the Cad 4.x engines into the 6000-7000+ RPM range... it isn't a matter of airflow, they are not made for that RPM, and either by, by the time the [4.9] hits it's 5250 redline, it is already loosing power.....

.... stock Fiero + stock 4.9 + any tranny that'll hold up to the power = instant low 13 second Fiero..... you can either use the 3spd auto from the Fiero, the 4T60E from the Cad, or the 4 or 5 speed manual (my choice).... results are similar to the s/c 3800....

the "motor" does determine how it revs. cams, heads, delivery system, intake, exhausts, valvetrain, etc. determines how a motor revs. he said he was going to put a new cam in, work the heads, headers and exhaust, new fuel system. if you are i don't think 6700-7000 rms is unrealistic with this much work and money invested. you might want to start looking for valvetrain though. don't know about the stock springs with a high lift cam. If you are going to make this a revver, then a 75-100 horse shot a funny gas about the top of 2nd gear would really make things interesting...

excuse me... i meant to say the "motor" DOES NOT determine how it revs.

excuse me... i meant to say the "motor" DOES NOT determine how it revs.

To some degree you were closer the first time, a long stroke motor like the 4.9 is NOT a high revver, the 4.5 by virtue of it's shorter stroke will rev higher so to some degree the "motor" does determine how it revs, of course any motor is the total sum of it's parts. From what I've learned about these motors so far you have to do a LOT of work to the valvetrain to keep them together at high RPM the weakest link being the rocker arm stands. If that is NOT correct somebody tell me now because that's what is holding me back from doing more mods.............

I see what you are saying about the stroke, i don't know why i didn't think about that when i replied. what's the redline on the 4-5? 5250 for the 4-9 right?

The thing that you are likely to have trouble with is the aluminum rocker arm support bars breaking with the bigger cams and higher RPM. in any case the bars will deflect and cause you all sorts of grief in the valve train department if you don't do something to them. I have seen several installations that heliarced small aluminum tabs to the intake manifold so that the rocker arm support bars could be bolted to the tabs to stiffen and brace them from bending. This is a "custom fit" sort of deal that has to be fabbed up on the specific engine but it is effective.

The other thing to do is to root thru the parts catalogue - the 89-92 Allante 4.5 engines and the export 4.5/4.9 PFI engines had forged STEEL rocker arm support bars that are much stiffer than the die cast aluminum bars. If I was to do any work on a 4.5/4.9 I would chase down a set of the forged steel bars first thing.

The thing that you are likely to have trouble with is the aluminum rocker arm support bars breaking with the bigger cams and higher RPM. in any case the bars will deflect and cause you all sorts of grief in the valve train department if you don't do something to them. I have seen several installations that heliarced small aluminum tabs to the intake manifold so that the rocker arm support bars could be bolted to the tabs to stiffen and brace them from bending. This is a "custom fit" sort of deal that has to be fabbed up on the specific engine but it is effective.

The other thing to do is to root thru the parts catalogue - the 89-92 Allante 4.5 engines and the export 4.5/4.9 PFI engines had forged STEEL rocker arm support bars that are much stiffer than the die cast aluminum bars. If I was to do any work on a 4.5/4.9 I would chase down a set of the forged steel bars first thing.

Been lookin' for a used set ever since you told me about them last year over at the now defunct GM Forums, may have to break down and try the local Cad dealer but buying new takes all the fun out of it... ANYBODY can do it that way........... ;)

then what do you do about valve springs if one had a camshaft ground?

are larger valves a good option? i read somewhere something about ford 300 valves are slightly larger, but need some kind of machining? this probably isn't worth the extra money (assuming you already had the heads off)

Got the soulution to that problem right here... LOL Just found this, looks like a good idea to me. Guy's never e-mailed me back though....

http://www.fieroaddiction.com/caddy49h.html


D.

Got the soulution to that problem right here... LOL Just found this, looks like a good idea to me. Guy's never e-mailed me back though....

http://www.fieroaddiction.com/caddy49h.html


D.
I had e-mailed him last year when I first started thinking about my 4.9 swap. Never heard back from him either.

then what do you do about valve springs if one had a camshaft ground?

You must buy new ones. Ones that will accomidate a higher lift. I'm sure you can find some for the 4.9. If not then the lift on the cam will have to be less agressive. Plus if you can't do headers, intake, and heads an agressive cam won't work well anyways, so a less agressive cam would be the way to go. Not sure the specs but I'm sure the cam is really mild on a stock 4.9 so if you could actaully swap that out and put headers, intake, and port/polish your heads, you would gain a lot of HP/TQ.

Later,
Dave

anyone know how much lift stock 4-9 springs can handle... safely and reliably??

what about specs on stock cam? assuming it's new and the lobes aren't worn!! hehehe

what about specs on stock cam? assuming it's new and the lobes aren't worn!! hehehe

Like HippieD9 (no relation ;) ) posted above, you will find this and the answer to questions you haven't even asked yet and may never ask at ......... fieroaddiction.com (http://www.fieroaddiction.com/caddy49a.html)
Check out the Performance Mods section, it goes a little deeper than just valve springs. Don't try to run a high rpm cam in a full size Caddy like the Fiero guys, they have a "slight" 3/4 ton weight advantage. 220 degrees duration @ .050" valve lift is a fairly lumpy cam in a small motor and will take away some of the low end torque you need to get a heavy car rolling. The wrong cam can completely ruin an otherwise great car, believe me I learned the hard way. I really wouldn't mess with the cam unless you're swapping your motor into a lighter car. Concentrate on maximizing torque in the low and mid range and utilizing it as efficiently as possible.

You'll get more from a gear change in the transaxle than you will from a cam change. I had a '92 S-10 with the 4.3, 700R4 and a 3.08 open diff, a coworker had the EXACT same truck except for a 2.56 differential. We got identical fuel economy but mine could blow his doors off and I mean BAD. The only difference was the final drive ratio. The stock Cad 4T60E has a final drive ratio of 2.84 to 1, changing gears requires removing and disassembling the trans BUT it will give you a very noticeable performance improvement albeit at the loss of some top end speed and fuel economy but it will get you to the next stoplight a lot quicker. Simply swapping the 35/35 drive sprockets from the Cad trans for the 33/37 sprockets from a 4T60E out of a 3.4 DOHC car will change your FDR to a 3.18 to 1 without changing the ring and pinion. Use the DOHC's 3.06 R & P as well and you get a 3.43, that's a difference you will definitely feel on the old "butt dyno". Or you can swap in the 3.33's from a 3.1 powered car as is or combine them with the 33/37 sprockets for a FDR of 3.73. If your doing a trans overhaul anyway it's the perfect time. Take a look at a torque converter out of a 3.8 full size car while you're at it to bump the stall speed up a couple hundred RPM but don't go crazy, the 4.9 will make it stall a couple hundred higher than what it was rated for behind the 3.8. The stock Cad conveter is a 1500 stall, a 3.8 converter rated for 1600 will probably be enough as the higher torque of the 4.9 is probably going to make it stall closer to 1800. Don't get carried away here, too loose of a converter will make your car MISERABLE to drive and generates a ton of heat which in turn will cook your trans.

The 4.9 can be made to run a lot better but as far as being "fast" I have to agree with 99Zee28, it will never be "fast" by musclecar standards. BUT.... it can be made to surprise the unwary who just see Grandpa's car sitting next to them and that's half the fun isn't it. ;) :lildevil: :coolgleam

now this is a LOOOOONG SHOT but.... would it be possible to convert say.. my 93 Seville 4.9 to a 5speed manual??? im not even sure if there is a FWD manual trans that would be able to mate up to the 4.9, I mean ive seen a 4.9 in an ISUZU TROOPER 5spd 4wd I kid you not!!! but i think the seville would be a hell of a better performance car if it could take a manual trans. if it can be done i would do it in a heartbeat if i hadnt just dumped $1600 on a new 4T60E.
Click this link to see that Isuzu
http://myweb.cableone.net/bcanderson/trooper/cadillac/cadillac.htm

now this is a LOOOOONG SHOT but.... would it be possible to convert say.. my 93 Seville 4.9 to a 5speed manual???
absolutely... as long as you have the $$...

What got me thinking was.... when people swap 4.9 in Fieros, they can keep them either auto, using the 3speed Fiero tranny, or 4speed using the Cad tranny... OR make it a 4/5 speed manual using either the getrag (sp) or Isuzu tranny.... I would think then you could get something rigged up in a Cad to accept it also....

I did a bit of research on this for my Allante. Here's what I've found:

There are really only two GM 5-speed manual transaxles that will bolt up (with modification for the starter) to the Cadillac block. They are the Getrag/Muncie 282 (the 5-speed used on V6 Fieros and Berettas) and the Isuzu used on I4 Fieros (and other vehicles, I suspect).

Other potential transaxles are the Muncie 4-speed used on V6 Fieros, and the ultra-rare Getrag 284 used on the 5-speed GTP and Z34 with the 3.1 circa 1989-1992.

Couple of issues:

First, the "easy ones".

1) You would have to modify or otherwise adapt the speed sensor
2) You would need to fool the ECM into thinking the transaxle was attached (for when it attempts to electronically shift it)
3) You would have to adapt the gear selector and neutral safety switches

More difficult:

1)Two of the three transaxle/engine mounts would have to be completely fabricated.

2) Driveshafts would have to be adapted/fabricated as the distances would all be different

3) The manual transaxle doesn't have a "snout" running across the back of the engine. Berettas had either a pillow block or a cast extension.

4) A flywheel would have to be custom made (or gotten from the Fiero guys)

5) The transaxles have to be cut to accept the stock Cadillac starter.

Even if you could accomplish all that...

1) Fieros have a hard time getting the clutch to handle the torque. There's not much space in there for a larger diameter one. This is a problem because

2) Cadillacs weigh a lot more than Fieros. It takes more torque to accelerate them, all things being equal, because there's more weight to haul around, thus more torque has to be transmitted and the clutch is already borderline, plus

3) Its easy to spin the tires in a Fiero with a Cadillac engine. This acts as a "safety valve", preventing the full torque of the engine from being channeled through the transaxle. That's not going to happen on a FWD Cadillac and it increases the odds of breaking something.

So, yes, you could probably do it. It may even last a long time if you don't abuse it, and rebuild the trans before installation. There are a lot of issues to sort out though. I suppose the first person that does it will gain some interesting experience!


Another avenue I've thought of pursuing was to adapt the manual trans off a Taurus SHO. That car weighs about the same as the Allante and it might last a bit longer than the Getrag 282, and certainly the Isuzu. Then, though, you have to deal with physically bolting it to the engine, and mixing Ford and GM driveshaft pieces.


Part of me would like to give it a try when I finish remodelling the house. If the trans wasn't such a PITA to drop out of the Allante, I might think about it more.

FWIW...