: Saw an interesting Swap today.... (56k take a nap)



DaveSmed
02-15-06, 07:18 PM
I was at school and heard something mean sounding pull in. I look around trying to figure out what it is, and find this:

http://mywebpages.comcast.net/davesmed/monte/Picture001.jpg

A 95 Monte Carlo With a Northstar! I never would have expected that! I had a talk to the guy who owns it, and he gave me the specs of the car, and the swap pictures. Very clean swap from what I saw.

Engine Mods:
- 1996 Cadillac Seville STS engine swap w/ 4T80-E transmission
- Converted to OBD I
- Cadillac Seville STS aluminum radiator/A/C condensor
- Port and polished heads
- 3 angle valve/seat grind
- 272 reground cams
- New HP springs, retainers, seals
- Intake cam sprockets redrilled
- High strength 13:1 compression pistons
- Forged connecting rods and crankshaft
- Block bored .030 over
- Custom Fender WelI Intake with K&N 9" cone
- Battery relocated to trunk
- ECM (PROM Calibrated by FAST) with a Perfect Power complete engine managment and fuel injection system managment Laptop hookup relocated to trunk
- Circuit board relocated to trunk
- TCI Transmission Computer from FAST which allows has the choice of line pressures, shift timing and firmness of shift for both upshift and downshift points, the ability to have part throttle shifts as a function of road speed while the Wide Open Throttle shifts can be a function of engine rpm in the trunk
- 3500 stall torque convertor
- Custom Posi traction and driveshafts
- Walbro 340 fuel pump
- Custom Flowmaster Outlaw race muffler side exit exhaust w/ no cat or resonator

Interior/Exterior Mods:
- Full painted red dash and door panels
- Red Sparco racing seats w/ 4 point racing harness
- Sony CDX-M8815X headunit
- JL Audio TR690-TXi 3 way 6x9's in the rear
- JL Audio XR525-CXi 5 1/4 Coaxial's in the front
- 70% tint all around
- Multivex sideview race mirrors
- 20" Akuza Padrone chrome rims with 255/35/20 Goodyear Eagle HP Ultra Plus tires
- 8000k HID upgrade kit for Low Beams 8500k Xenon High Beams
- Cross drilled and slotted rotors
- Red powder coated calipers and drums

http://mywebpages.comcast.net/davesmed/monte/DSC01614.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01620.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01629.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01630.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01638.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01639.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01640.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01641.jpg

http://mywebpages.comcast.net/davesmed/monte/DSC01643.jpg

DaveSmed
02-15-06, 07:23 PM
http://mywebpages.comcast.net/davesmed/monte/Picture002.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture003.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture004.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture005.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture006.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture007.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture008.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture009.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture011.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture012.jpg

DaveSmed
02-15-06, 07:28 PM
http://mywebpages.comcast.net/davesmed/monte/Picture014.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture015.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture016.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture017.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture018.jpg

http://mywebpages.comcast.net/davesmed/monte/Picture019.jpg



For those who undoubtedly want to hear it, here's a video: http://mywebpages.comcast.net/davesmed/monte/Picture022.avi



.

eldorado1
02-15-06, 08:02 PM
I wouldn't be surprised if he has $20k into it.

GreenMachine
02-15-06, 08:07 PM
I'd be curious to find out what kind of HP and lbs-ft he gets on a dyno with that. Take into account the weight of the versus an STS and you have a fast Monte Carlo :)

eldorado1
02-15-06, 08:16 PM
If chrf did the porting, probably 285+ at the wheels. 272 is a pretty mild cam.

A monte and a STS weigh pretty close to the same...

95 monte curb weight: 3306
96 STS curb weight: 3910

the 4t80e is giong to add 200lbs over stock, so it's 3500 vs 3900lbs...

CadillacSTS42005
02-16-06, 12:25 PM
wow... id race it lmfao

Eldo1 is porting a N* that beneficial i herd it really isnt worth it

eldorado1
02-16-06, 01:33 PM
Absolutely it's worth it!

CHRF quote:

Head work with our cams will really wake up this engine. Figure an increase of 50 cfm will produce 100 HP.

Their port and polish does show an increase of 50 cfm.

CadillacSTS42005
02-16-06, 02:20 PM
damn so by porting/polishing the heads and throwin on the 80 mm tb u sell im lookin at a 105 hp increase? itd be expensive as hell tho considering the fact that the heads must be removed and then the headgaskets replaced etc etc etc

samm
02-16-06, 03:22 PM
thats why you do all the grunt work yourself

CadillacSTS42005
02-16-06, 10:57 PM
im 19 and while very knowledgeable about general mechanics i have no means to drop the cradle or pull the N*

Tommy Deville
02-18-06, 09:41 PM
Looks like it just makes it

Katshot
02-19-06, 09:26 AM
Hey Dave, any chances this guy will make it to E-Town for the meet? I'd love to see the car.

eldorado1
02-19-06, 02:26 PM
damn so by porting/polishing the heads and throwin on the 80 mm tb u sell im lookin at a 105 hp increase? itd be expensive as hell tho considering the fact that the heads must be removed and then the headgaskets replaced etc etc etc

No, when you have high flowing heads, the intake starts to become an even larger restriction. You can't just add them up. It would probably be more like, +80hp increase with the stock intake, +100hp increase with a bored TB and spacer.

From what I've heard, the stock intake becomes a problem >400hp. NA of course, boost doesn't care.

Anybody have any more information on the ECM? Is it just a rechipped stock computer? SFI?

danbuc
02-19-06, 03:55 PM
Porting your heads isn't gonna do much unless your running a F/I system on the car. First off, the engine is only gonna draw in as much air as it can. By increasing the diameter of the intake ports, you increase overall volume, but reduce the velocity of the intake charge. What this means is, even though you can now flow more air, it's not packing in as much into the cylinders because of the reduced speed. You end up with little or no bottom end, and a strong top end. Completely useless in a street car as heavy as a Cadillac. Of course if you are runing a F/I system like a turbo or supercharger on it, then you want that extra volume of air. The velocity of the intake charge will be sped up by the turbo or supercharger anyway, so that no longer becomes and issue. You don't want to polish th eintake ports anyway, since you remove the swirling action that help produce a good A/F misture within the cylinder. A properly sized cam will also be needed to make full use of the ported heads. No sense in increasing the intake port, if the valve is still only gonna open the same amount, and draw the same volume of air in each time it opens. You would need a larger cam, with more duration and lift in order to draw in the maximum amount of air possible. With a larger the cam though, you end up with less bottom end power, since you have to spin it up fast enough so that the increased overlap is no longer a problem. Of course at higher RPM, cylinder scavenging will be more efficient, which in turn helps velocity. That's why big overlap is a problem at low RPM's, it hurts low end exhaust scavenging, which is used to help draw in the intake charge.


A good example of this would be all these full out race engines you see with tunnel ram style intakes, and big cams. They can barely idle because the velocity of the intake charge is so slow. They usually haave a usuable power band between 3/4000rpm- over 7/8000rpm.

As I mentioned before, velocity becomes a moot point when going the F/I route, since the air is being "forced" into the intake. You don't have to worry about the engine not being able to draw the air in fast enough.

eldorado1
02-19-06, 05:02 PM
You would need a larger cam, with more duration and lift in order to draw in the maximum amount of air possible.


You're right, sorry. The heads flow 50cfm more, but that's their theoretical maximum. In actuality, the stock engine wouldn't be capable of flowing a whole lot more. Less restriction will probably gain you 20+ hp on an otherwise stock engine. On the mustang 4.6DOHC, they gain 40hp with just a good porting. I don't think anybody's tested just a port on a northstar.. If you're paying $1000-3000 for the work, $450 for cams is cheap. Have to make good use of the porting.

However, I disagree with your "no bottom end" part. Less intake velocity, yes, but on the scales we're talking about, removing a mm from around the port here and there, etc, it won't be noticeable.

danbuc
02-19-06, 05:41 PM
Well, I think mark said that when he tested his car after the port job before the turbo, his times actually increased.

As far as no bottom end, I was more or less reffereing to a more radical port job. With our heads, the amount you'd have to remove to really see a difference might not affect the bottom end that much, but it certainly won't help it. Those larger cams that CHRFab sells though, are the worst thing you can add if your looking for bottom end. The overlap on those cams is so great, that in a street car, you wouldn't have much low end torque at all, just what you don't need.

Like you said, a mm here or there won't really make much of a difference, but that's just it. Taking off such a small amount simply isn't worth the trouble in the long run. If your gonna go the F/I route, than that's where a major port job really pays off.

cart69
02-19-06, 10:26 PM
very nice job, more and more now that i have 2 96 sts motors sitting around do i wanna put one into my 91 z28 vert!!!!

SL1CK
02-20-06, 10:43 AM
what the heck does that 56k crap mean???

eldorado1
02-20-06, 11:28 AM
what the heck does that 56k crap mean???

56k = dialup modem. All the pictures would make for a slow page load. So, take a nap while it loads. :thumbsup:

Katshot
02-20-06, 12:02 PM
Porting your heads isn't gonna do much unless your running a F/I system on the car. First off, the engine is only gonna draw in as much air as it can. By increasing the diameter of the intake ports, you increase overall volume, but reduce the velocity of the intake charge. What this means is, even though you can now flow more air, it's not packing in as much into the cylinders because of the reduced speed. You end up with little or no bottom end, and a strong top end. Completely useless in a street car as heavy as a Cadillac. Of course if you are runing a F/I system like a turbo or supercharger on it, then you want that extra volume of air. The velocity of the intake charge will be sped up by the turbo or supercharger anyway, so that no longer becomes and issue. You don't want to polish th eintake ports anyway, since you remove the swirling action that help produce a good A/F misture within the cylinder. A properly sized cam will also be needed to make full use of the ported heads. No sense in increasing the intake port, if the valve is still only gonna open the same amount, and draw the same volume of air in each time it opens. You would need a larger cam, with more duration and lift in order to draw in the maximum amount of air possible. With a larger the cam though, you end up with less bottom end power, since you have to spin it up fast enough so that the increased overlap is no longer a problem. Of course at higher RPM, cylinder scavenging will be more efficient, which in turn helps velocity. That's why big overlap is a problem at low RPM's, it hurts low end exhaust scavenging, which is used to help draw in the intake charge.


A good example of this would be all these full out race engines you see with tunnel ram style intakes, and big cams. They can barely idle because the velocity of the intake charge is so slow. They usually haave a usuable power band between 3/4000rpm- over 7/8000rpm.

As I mentioned before, velocity becomes a moot point when going the F/I route, since the air is being "forced" into the intake. You don't have to worry about the engine not being able to draw the air in fast enough.

Nice post!
At least some people here understand that engine components need to be thought of a on a relational basis. This is why I like to try to point out to beginners that simply popping a bigger throttle body, exhaust or other component won't always net you an increase in performance. It can (and usually does) upset the careful balance the OEM has engineered into the engine.

DaveSmed
02-20-06, 12:04 PM
Hey Dave, any chances this guy will make it to E-Town for the meet? I'd love to see the car.
I'll be sure to ask him. I have off today, so next time I see him I'll ask about the ECU too.

eldorado1
02-20-06, 01:02 PM
Nice post!
At least some people here understand that engine components need to be thought of a on a relational basis. This is why I like to try to point out to beginners that simply popping a bigger throttle body, exhaust or other component won't always net you an increase in performance. It can (and usually does) upset the careful balance the OEM has engineered into the engine.

Anything you can do to get more air into or out of the engine is going to increase performance, within reason. Going to a 100mm throttle body or dual 4" truck exhaust actually will hurt performance - so that's why I have to say "within reason". I also find that statement somewhat hypocritical, considering you have a k&n intake, and flowmaster exhaust.

Swapping in 288 degree duration cams will help performance, you'll gain 100hp over stock. You can probably drop a second of your 1/4 mile time - however - most people here wouldn't want them because most people's cars here are daily drivers, and don't spend much time above 4000rpms. In order to realize the gain in performance, you'd have to drive it like your throttle is an on/off switch.

Katshot
02-20-06, 02:04 PM
Anything you can do to get more air into or out of the engine is going to increase performance, within reason. Going to a 100mm throttle body or dual 4" truck exhaust actually will hurt performance - so that's why I have to say "within reason". I also find that statement somewhat hypocritical, considering you have a k&n intake, and flowmaster exhaust.

Swapping in 288 degree duration cams will help performance, you'll gain 100hp over stock. You can probably drop a second of your 1/4 mile time - however - most people here wouldn't want them because most people's cars here are daily drivers, and don't spend much time above 4000rpms. In order to realize the gain in performance, you'd have to drive it like your throttle is an on/off switch.

This is what I was talking about. There ARE some things that can be "tweaked" and net you some performance. In my car's case (I say this because every car is different), the airbox and exhaust are known restrictions. My modifications to those systems have taken away those restrictions and now moved the "weak-link" as it were to another component (in this case, head/cam combo). On "most" stock cars, there's at least a couple areas that you can do relatively minor mods to and realize gains in performance. In many cases, there may be a trade-off for that gain. With the '95 Fleetwood, IMO, the mods I made were all that can be made without making what I would consider major trade-offs. Plus, I have the added benefit of knowing that my intake and exhaust have plenty of excess flow capability so I "could" resume my quest for increased power by changing the cam and heads. Of course that would most likely cause me to revisit the exhaust and install headers and at the very least, high-flow cats. And then, probably a bigger throttle body at some point along with a bigger MAF. You see, it's a domino effect, and I really didn't want to get into that.
My car was a project that I brain-stormed about years ago while working with Cadillac, and it was only intended to be a styling exercise with some minimal performance upgrades along the lines of what Cadillac did to differentiate the STS from the Seville line. I feel I've accomplished that goal and managed to put together an interesting car that's even more enjoyable to drive than I had imagined. You see, I'm not just some performance-crazed guy that wanted to have a hot-rod Cadillac. If THAT was the idea, my FTS would be MUCH faster, but probably not as enjoyable to drive.

SL1CK
02-20-06, 10:34 PM
Oh ok, I didn't know he was talking about modems and internet speed...I have no need to worry....cable here...

96-deville-man
02-21-06, 01:43 AM
Anything you can do to get more air into or out of the engine is going to increase performance, within reason. Going to a 100mm throttle body or dual 4" truck exhaust actually will hurt performance - so that's why I have to say "within reason". I also find that statement somewhat hypocritical, considering you have a k&n intake, and flowmaster exhaust.

Swapping in 288 degree duration cams will help performance, you'll gain 100hp over stock. You can probably drop a second of your 1/4 mile time - however - most people here wouldn't want them because most people's cars here are daily drivers, and don't spend much time above 4000rpms. In order to realize the gain in performance, you'd have to drive it like your throttle is an on/off switch.

so if i swap in a set of 288cams i can gain 100hp? ide like to look into that and do that at the same time that i plan of having a custom set of headers and exhaust. how would those work with a custom supercharger setup? my goal is to get about 400whp N.A. and 100hp from cams with the custom exhaust and a valve job would get me there.

danbuc
02-21-06, 07:30 AM
That extra 100hp is no good, if you can't move the car. You have to understand that there's a serious trade-off for gaining 100+hp at the top of your power band. In this case, the trade-off is loss of low end torque. Without that torque down low in the power band, your car is gonna be slow as hell. That's why you can't just throw these cams in there, unless your planing on supercharging, or turbocharging the car. It simply isn't going to work. When I spoke iwth CHRFab about it, they said that they had one guy who tried the cams out in his car, and a few weeks later he pulled them out, and put the stock ones back in. The reason for this, was that he said he had almost no low end power, and the car would barely move off idle. This 100hp is also gonna come in at around 5k rpm or so, completely useless for a street car. Hay, if you wanna do it though, it's your money. Good luck.

eldorado1
02-21-06, 11:44 AM
so if i swap in a set of 288cams i can gain 100hp? ide like to look into that and do that at the same time that i plan of having a custom set of headers and exhaust. how would those work with a custom supercharger setup? my goal is to get about 400whp N.A. and 100hp from cams with the custom exhaust and a valve job would get me there.

You're going to need a custom computer set up to actually control it, but yes. I don't think you can swap the cams to something that radical without touching the torque converter though. You want a minimum 3000rpm stall. Stock is like 1800rpm. If the converter locks up that soon, it's going to bog with the new cams, which I'm guessing is what the guy danbuc's talking about had. "everything on a relational basis", right? :bouncy:

chrf can change the cams a bit to set them up better for boosted applications.

danbuc
02-21-06, 02:53 PM
Yeah a 3000rpm stall speed would work well with the cams.....in a race application. It just isn't practicle to have to floor the gas at every stop light, just to get the car moving down the road. Not only will that waste large ammounts of fuel, but it will result in excessive heat, and less life out of the tranny and associated drivetrain parts.

Katshot
02-21-06, 03:31 PM
Yeah a 3000rpm stall speed would work well with the cams.....in a race application. It just isn't practicle to have to floor the gas at every stop light, just to get the car moving down the road. Not only will that waste large ammounts of fuel, but it will result in excessive heat, and less life out of the tranny and associated drivetrain parts.

Agreed. My thoughts exactly.

eldorado1
02-21-06, 03:39 PM
Well higher stall torque converters aren't my area of expertise, so I posted a question to Mark in his turbo thread, which I hope he sees. I'm pretty sure I remember him saying he had one before the turbo...

Now as I understand it, it works just like a clutch, so it's basically like feathering the clutch around 3000rpm instead of 1800. So when you actually step on the gas, with a normal acceleration, instead of the engine slowly climbing to 1200 or so, it will jump to 2500 and start accelerating. But I don't want to put words in Mark's mouth, so I'll let him tell us what it's like.

96-deville-man
02-21-06, 04:11 PM
That extra 100hp is no good, if you can't move the car. You have to understand that there's a serious trade-off for gaining 100+hp at the top of your power band. In this case, the trade-off is loss of low end torque. Without that torque down low in the power band, your car is gonna be slow as hell. That's why you can't just throw these cams in there, unless your planing on supercharging, or turbocharging the car. It simply isn't going to work. When I spoke iwth CHRFab about it, they said that they had one guy who tried the cams out in his car, and a few weeks later he pulled them out, and put the stock ones back in. The reason for this, was that he said he had almost no low end power, and the car would barely move off idle. This 100hp is also gonna come in at around 5k rpm or so, completely useless for a street car. Hay, if you wanna do it though, it's your money. Good luck.

If you didnt see in my post i plan on doing a custom supercharger setup with it. I understand what your saying about the trade off. do you know of a good cam that has good all around power and still be safe under around 10-14psi of boost. now i know ill have to drop my compression down alot to run that kind of boost but i will be putting alot of money into this car. within a few years. My freind down the street has a 3000rpm stall in his supercharged ram1500 and his will move the truck from about 1700rpm up.

danbuc
02-21-06, 04:13 PM
The converter mark has, has a flash stall speed of 3600rpm. This means that it will in a sense "lock up" at 3600rpm, and create a near solid coupling between the flexplate and input shaft to the trans. Almost like dumping the lcutch in a manual at 3600rpm. The thing abotu marks converter is, it's also designed to slip, with various stages of viscous coupling like the OEM unit does. This means, that you can roll into the power at a stop light, and not have to floor it. The engine torque is enough, to cause the pump side of the converter, to interact with the turbine side and stator. Without this low end torque (e.g. an Northstar with much higher lift cams, such as those from CHRFab) the engine has to work much harder to get the converter to spin the input shaft. This more or less equates to less movent and overall acceleration, and more heat. Mark did install an external trans cooler since the 3600rpm stall converter he got is gonna slip just a little more than the stock unit. He id mention that his was designed to have the driveability of a 2800rpm unit, but still be able to stall at 3600rpm when under high load. Somehting like this would be preferable for daily use. It all comes down to one thing....does the car have the power to efficient accelerate the vehicle. I mean, you wouldn't throw a 3 puck racing clutch on a car that would just stall when you engaged it.....you would need the low end power to keep the drivetrain spinning. I kinda went off on a tangent with that one, but you see where I'm goin with this. In short, a higher stall speed converter can be beneficial to performance without hurting driveability. Cam's don't have the same attributes. They either help, or hurt. That is unless your using variable cam timing like VVT or whatever.

eldorado1
02-21-06, 04:36 PM
I mean, you wouldn't throw a 3 puck racing clutch on a car that would just stall when you engaged it.....you would need the low end power to keep the drivetrain spinning. I kinda went off on a tangent with that one, but you see where I'm goin with this. In short, a higher stall speed converter can be beneficial to performance without hurting driveability. Cam's don't have the same attributes. They either help, or hurt. That is unless your using variable cam timing like VVT or whatever.

You had me until about that paragraph.

Lets do an example with imaginary numbers...

Stock northstar powered car, takes 40hp to get a good average acceleration off a stoplight. Stock stall is 1800rpm, and it makes 80hp there at wide open throttle, lets assume the throttle of an "average acceleration" limits it to 40hp as needed. "Perfect balance" as it was said before.

Northstar car with cams and stall converter, still takes 40hp to get a good average acceleration off a stoplight. However, the cams now cause it to make 40hp at 1800rpm (throttle position limits actual output to 20hp). No good for acceleration, but the 3000 rpm stall converter lets the car get to it's powerband, and it is making 140hp at 3000 rpm. (of course, assuming a "normal" accelerator position, it is making the same 40hp as before)

The stall converter between the 275hp and 300hp northstars changed by a bit, I believe it was 2-300 rpm. The only difference was a little more duration on the intake cams for the 300hp northstar. Everyone says they need low end torque, but I don't see everyone with a 275hp northstar... The 275 makes more torque all the way up to 4800rpm, a full 8ft-lb more.

danbuc
02-21-06, 06:51 PM
Stock northstar powered car, takes 40hp to get a good average acceleration off a stoplight. Stock stall is 1800rpm, and it makes 80hp there at wide open throttle, lets assume the throttle of an "average acceleration" limits it to 40hp as needed. "Perfect balance" as it was said before.


First off, it doesn't take any hp to get good average acceleration. It takes torque. Torque is the turning force produced by the engine. The more torque the engine's producing, the quicker and easier it can spin the drivetrain, thus resulting in quicker acceleration. Horsepower on the other and is the engine's ability to do work in given time, or more simply stated, the engine's ability to carry the previously mentioned torque up through the rpm range. The N* could be making 500hp with cams, ported heads or whatever. All that hp isn't going to help when you go to launch the car and you've got no low end torque. The L37 engine for example produces it's peak Torque output at a lofty 4400rpm. That's one reason for why these cars struggle off the line. Add a 3200rpm stall converter, and you end up launching with more torque (i.e. more overall power). You throw a set of cams in there, and you overall torque output may increase, but it's gonna peak much higher than 4400rpm. Say your now making 500hp at 7000rpm with those cams(which is probably where that power would be achieved), you now gonna end up making maybe lets say, 450lb ft of torque but around 5500-6000rpm. That's the trade off. Even though your now making this much more hp and torque, you've gotta run the rpms up to make you of it. It really is a lose/lose situation as far as gaining either hp or torque is concerned. If you want a strong bottom end, you'll have to sacrifice top end power. On the other hand, if you want a strong top end, you'll haev to sacrifce bottom end power. It's the way it has always been when designing and engine....that is until variable valve timing came out. With that system, you can pretty much have you cake and eat it too. Tha's because it allows you to have the equivelant of a lower lift/ shorter duration cam at low rpm (less hp, but more low end torque/ good of acceleration), and at higher rpm, it acts liek a high lift/ long duration cam, which is excellent for high rpmj hp, but produces much less torque.

Katshot
02-21-06, 06:54 PM
IMO, a higher stall converter WILL hurt "normal" driveability. To a performance-oriented guy, it will probably not be noticable though since his foot's in the throttle more than normal anyway. But the extra heat generated and loss of MPG are not debatable.

eldorado1
02-21-06, 07:53 PM
First off, it doesn't take any hp to get good average acceleration. It takes torque.

It doesn't? :eek:

Okay, then I'll swap your northstar for a 5hp briggs and stratton, with a nice gearbox that will provide you with 500 lb-ft of torque. We'll see how fast you can accelerate.

You'll do good until about 3 mph.

danbuc
02-22-06, 01:01 AM
I don't think there's any way that you could have missed the point of my post more than you already have. Torque is what throws you back in the seat when you mash the pedal. HP is what keeps that torque around (i.e. what allow you to pass on the highway) when you turning 5000rpm at 170mph. And to directly answer you post, a 5hp Briggs & Straton engine with 500 ft/lb's of torque would out accerelate the N* hands down off the line. It won't be able to keep the acceleration going because of it's low amount of hp, but that's exactly the point I was trying to make. For off the line acceleration, hp means absolutely nothing. Do you think if an 18 wheeler had only 200 ft/lb's of torque but for arguments sake 1000hp, that it would be able to move a trailer.....hell no it wouldn't. Why not give it 10,000hp....it's still not gonna move the trailer. Why, because it's got no LOW END torque.

Katshot, as you were saying, any stall speed higher than stock can hurt performance. In Mark's case, he installed an external trans fluid cooler to help with the heat. He did tell me though, that when he had the 2800rpm stall speed converter in his car, that he never noticed any real loss of mileage. Maybe 1mpg or so, but he said it wasn't really noticeable. Of course, like you said though, if your someone who drives the car pretty hard with your foot in the throttle all the time, then you probably wouldn't notice it at all.

Edit: To add to this, where do you think the LT1 in Katshot's Fleetwood develops it's peak torque at. I'll guarantee you it's lower than 4400rpm. If that LT1 was making it's peak torque where the N* does, it's be a hell of alot slower.

Katshot
02-22-06, 07:23 PM
Exactly, That's why I always cringe when guys talk about changing cams etc. on these big LT1-powered boats. Yeah, you can beef-up the top end but you sacrifice that wonderfully wide, low powerband that makes these cars so nice to drive in the everyday environment.

eldorado1
02-22-06, 09:15 PM
I don't think there's any way that you could have missed the point of my post more than you already have. Torque is what throws you back in the seat when you mash the pedal. HP is what keeps that torque around (i.e. what allow you to pass on the highway) when you turning 5000rpm at 170mph. And to directly answer you post, a 5hp Briggs & Straton engine with 500 ft/lb's of torque would out accerelate the N* hands down off the line. It won't be able to keep the acceleration going because of it's low amount of hp, but that's exactly the point I was trying to make. For off the line acceleration, hp means absolutely nothing. Do you think if an 18 wheeler had only 200 ft/lb's of torque but for arguments sake 1000hp, that it would be able to move a trailer.....hell no it wouldn't. Why not give it 10,000hp....it's still not gonna move the trailer. Why, because it's got no LOW END torque.

Katshot, as you were saying, any stall speed higher than stock can hurt performance. In Mark's case, he installed an external trans fluid cooler to help with the heat.

Danbuc, you can move a semi trailer with a pissant with enough gearing. HP will tell you how fast it will move. The 500ft-lb briggs powered car will out accelerate a stock northstar, but the fraction of a second it does so will make it SLOWER. That's HP at work. It takes time to accelerate to 30mph. Torque is a force, acceleration requires force acting over some finite amount of time - You can push as hard as you want on something for 0 seconds, but it's not going to accelerate.

btw, Danbuc, do you remember what our old friend "Rob" said about what mods he would do to a stock Northstar, over anything else? He said he would extrude hone the manifolds, and drop on a 3000 rpm stall converter to make up for the low end torque. Why would he say that if it weren't streetable or helped performance? Call Yank, and ask them if any of their northstar customers returned their converter for a refund due to bad performance.

davesdeville
02-22-06, 10:32 PM
I think the torque multiplication of a high stall convertor would do well with some mild grind cams. I'd think it would take a very high stall (36-3800 or so) to make up for the loss of low end, even with 272/274 dur. cams. The Monte Carlo has a 3500 stall, it would take a bit more in a heavier Caddy to get the same feel.

Dave, you should ask the Monte owner to give you a ride in this thing and give us your impressions of the low end, both at WOT and just regular acceleration.

danbuc
02-22-06, 10:33 PM
Danbuc, you can move a semi trailer with a pissant with enough gearing. HP will tell you how fast it will move. The 500ft-lb briggs powered car will out accelerate a stock northstar, but the fraction of a second it does so will make it SLOWER. That's HP at work. It takes time to accelerate to 30mph. Torque is a force, acceleration requires force acting over some finite amount of time - You can push as hard as you want on something for 0 seconds, but it's not going to accelerate.

btw, Danbuc, do you remember what our old friend "Rob" said about what mods he would do to a stock Northstar, over anything else? He said he would extrude hone the manifolds, and drop on a 3000 rpm stall converter to make up for the low end torque. Why would he say that if it weren't streetable or helped performance? Call Yank, and ask them if any of their northstar customers returned their converter for a refund due to bad performance.


WTF are you talking about. Your just restating what I have already said in my last two posts. Torque is the turning force produced by the engine. Horsepower, is the engine's ability to carry that Torque up through the RPM range, so that it is still usuable at higher speed.

You said that the 500lb Briggs and straton engine WOULD out accelerate the N* but that the fraction of a second that it does will make it "SLOWER". If it's slower, than it wouldn't be out accelerating the N*. You really have to think before you write something like this. It just doesn't make any damn sense. It's only gonna be slower in the long run, because it doesn't have the high level of HP needed to carry that torque to a high enough RPM. Off the line though, it's still gonna win. Sure, it won't get very far before it runs out of gear, but it'll get to that point faster than the N*.

As for moving a trailer with a pissant with enough gearing, yeah it'll move, but it's only gonna go so fast. You need HP, to get the engine spinning fast enough so that it isn't crawling across the road. Let's say the average Semi engine has 300hp (YES, it's that little), they have well over 6-700 lb/ft of torque. Usually available off idle, but only up into relatively low RPM's. This is why they can pull those trailers, but can't sustain very high speeds, or pass quickly on the highway.

Here's good, simple example of what I've been talking about for the last day and a half. Say you have a Dodge Ram with the Cummin's inline 6, and an Acura Integra type R, with the DOHC Inline-4. The Cummin's engine is probably making around 250-300hp, but around 600lb/ft of torque. That Integra is making about 190hp, and around 125lb/ft of torque. Now, if you line them both up at the 1/4 mile track, which one do you think is gonna post a better 60ft, and 1/8 time. The Dodge will, becuase it has lots of low end torque and will easily out launch the Integra. The Integra is gonna have a better 1/4 time, and trap speed, because it has that high end HP to pull it along at higher speeds. What this means si very simple. Torque=Quick Accerlation, and lots of low end power. HP=slower accerlation, and lots of top end power.

Here, I've got an even better example. Say you gave the SLS the same 3.71:1 final drive ratio that the STS has. The SLS would out launch the STS off the line, but the STS would achive an overall greater top speed. WHY? Because the SLS is making 300lb/ft of torque at 4000rpm, where the STS makes 295 at 4400....therfor the SLS is at an advantage off the line having more low end torque avaiable for quick acceleration. The STS with it 300hp at 6200rpm though, will still be able to carry it's torque further up into the power band, and therfor will be able to push the car faster than the SLS, since it only has 275hp around 6000rpm or so.

Finally, with regards to the Torque Converter comments you made.....you a f**kin' idiot. You obviously for the second time, have completely missed the meaning of what I have posted. I suggest that you go back, and reread what I have said regarding this matter. It's obvious you either didn't read it, or comprehend it for that matter, other wise, you wouldn't have said what you did.

danbuc
02-22-06, 10:45 PM
I think the torque multiplication of a high stall convertor would do well with some mild grind cams. I'd think it would take a very high stall (36-3800 or so) to make up for the loss of low end, even with 272/274 dur. cams. The Monte Carlo has a 3500 stall, it would take a bit more in a heavier Caddy to get the same feel.

A higher stall speed converter will work wonder with a bigger cam. The real issue is, is it driveable on the street. Most peopel would say no. I know I would engine having to give it 3/4 throttle to get the same level of accerlation I do now with 1/4 throttle. A Higher stall speed converter would work much better with the stock setup. With the cams, you have to rev higher to get the same results, therfor it's not as efficient. That Monte Carlo also way a good deal less than the averge Cadillac. In fatc it was eldorado1 who posted the curb weights for both vehicles. According to his info, the Monte Carlo is over 600 pounds lighter. That's a pretty damn big difference. Hell, my STS would be running low 14's if it weight 600 pounds less. With less weight, you can sacrifice your low end torque for more top end power, since you don't need as much of it.

eldorado1
02-22-06, 11:44 PM
If it's slower, than it wouldn't be out accelerating the N*.


I think the problem is you are talking about instant acceleration, while I am/was always talking about an acceleration to a cruise speed, like 30mph.



..you a f**kin' idiot.

Thanks for keeping this professional. Can't have a disagreement with you without it becoming a personal attack. I'm done with this thread.

danbuc
02-23-06, 12:45 AM
Hay, it's not my problem if you can't comprehend what I say.. That's your deal, not mine. There's no point in keeping it proffessional, your replies are nothing more than my previously stated posts, which you then twist around to use as material for this argument. You can say what you want about how you were reffering to a specific speed, or a particular application, or what have you. I wasn't. I was making general statements regarding the differences between torque and horsepower, and the benefits/trade off's from loosing or gaining one or the other. Every post I've made, you've somehow found a way to question it, and reply with a comment that in most cases just doesn't make any sense. 20, 30...130mph, it doesn't matter. Low end torque is what wins a stop light to stop light race. NOT high end horsepower, that's for the Autobahn. That's all I have been trying to say, yet you just don't get it. I've tried to explain it, I've given numerous examples as well. All I ask is that if you make a statement, have the information to back it up. You asked about Torque converters, and I replied with an explanation. You mentioned the cams, and I responded with a logical, and well thought out explanation of why they simply aren't practicle in a 4000lb daily driver. If you can't deal with the fact that putting Cams in a N* while it's still in a 4000lb daily driver is a stupid idea, then you should be posting here. It's as simple as that. If your gonna comment about such things, you have to be willing to take criticism for it when your wrong. I know when I've been beat, and leave it alone. I don't keep arguing with the person, until I get to the point, where I'm arguing with myself. My suggestion is to quite while your not too far behind. I'm sorry if this sounds condescending, but at this point, I think this is the only way I'll ever get my point across. I wasn't gonna respond, but I figured I should dignify you with an explanation for my actions. Anyway....I've grown weary of this and won't be replying to this thread anymore either. Perhaps next time, it won't go this far...but one can only hope. Until then, I suggest you find a book on basic automotive fundementals and start reading. You could certainly use it.:thumbsup:

davesdeville
02-23-06, 02:40 AM
A higher stall speed converter will work wonder with a bigger cam. The real issue is, is it driveable on the street. Most peopel would say no. ...

You know what, I don't think you can make a determination on what people would say until someone has built a car with a really high convertor and cams. The higher stall the convertor the more torque multiplication... it may or may not "make up" for the low end loss from the cams. Hence me asking Dave to get his impression.

No way a Monte Carlo with a Northstar in it is gonna weigh the same as or less than a Monte Carlo with a 3.1 V6. It's a bit over 3300 with the 3.1 AFAIK, and an ETC is just over 3800. That's a 500lb difference to start with. Northstars are light but I seriously doubt it could be lighter than any of the 60* V6s, even the dohc 3.4.

It doesn't matter to me, I'm not going to do cams simply because I bought the ETC to be fuel efficient. I'm only going to consider a convertor after I've installed my nitrous kit if I feel I can launch better with it without losing traction all kinds.

davesdeville
02-23-06, 02:42 AM
you a f**kin' idiot.

Is it just me or is that one of the most ironic statements ever? :bigroll:

danbuc
02-23-06, 07:34 AM
You know what, people have tried. Most drag car's you see with an Automatic trans out there,are probably running a High lift cam, with a high stall speed converter. Are they a daily driver....no. That ALL I've been trying to say. Driveabilty with a high stall speed torque converter does suffer. The amount may be negligable to the avergae river, but it is affected. Adding a set of cams that shifts the torque further up the power band, will only exacerbate the problem. AGain, the driver may, or may not notice this depending on their driving style, but it does happen.

Also, building a torque converter with a high stall speed, doesn't mean you going to get more torque multiplication out of it. Until it reaches that stall speed, it's gonna slip more than the OEM unit. This is part of the reason for Mark (or any sensible person runnign avery high stall speed converter) to put in an external heavy duty trany cooler.

Once again, I have to re-axplain myself. The argument here is not whether it's possible, or even logical to do these kinds of mods to a car. It's whether or not it will make the vehicle less driveable on the street. That's all. The real point of this argument has been completely lost of over the last series of posts.

MARK99STS
02-23-06, 03:01 PM
wow... id race it lmfao

Eldo1 is porting a N* that beneficial i herd it really isnt worth it

Porting the heads on a stock aplication is worthless because the crossover pipe is the chokepoint for the N* in a stock application. What CHRFAB is talking about is NOT in a stock application. I had a 27cfm increase in my heads after porting, but my times were actually slower, because the exhaust is restricting the motor. I had already opened it up as much as possible with the Corsa and open intake, but untill you open that pipe, your stuck.

My 3600 stall converter was in before the turbo and it is totally streetable. As KATSHOT said I know I have lost mileage and it definitely runs hotter. That is why I installed the tranny cooler. But unless you were an expert, you would never know it had a higher stall converter in it. I can't speak for all, but this applies to YANK converters.

danbuc
02-23-06, 05:17 PM
How much worse is the mileage compared to the 2800rpm converter you used to have? I think I remember you telling me a long time ago, that with the 2800rpm one, the difference between it, and the stock one was negligible. I can't remeber though.

MARK99STS
02-23-06, 05:29 PM
How much worse is the mileage compared to the 2800rpm converter you used to have? I think I remember you telling me a long time ago, that with the 2800rpm one, the difference between it, and the stock one was negligible. I can't remeber though.

I now it is worse, but I couldn't tell you how much as I am the high performance guy with my foot in it all the time and don't really look at the mileage. I know I am getting 24mpg on the highway now with the turbo and 42lb injectors as I checked it on the trip to the dyno. Otherwise I am clueless. Actually I could care less what the mileage is as long as it has kick ass power.