: N* performance approach?



caddygirlny
10-01-04, 08:27 PM
Hey people. Im new at this so be easy on me. I just started doing the northstar stuff the day my GF got her 99. which was maybe 3 weeks ago. hehe.
heres the deal. I already bought her a pair of 4.6L cylinder heads, full with rockers , cams etc... beautiful, amazing condition, 150 bucks, i couldnt pass it up. I wanna port them out, leave the cams stock of course, only thing id like to do is get stainless steel valves with that, no guides, no new retainers, everything else original, i dont wanna go overboard with this car with aftermarket. I just wanna clean the ports a little more etc...
next i picked up the intake manifold with the TB at a junkyard with injectors for 75 bucks, so whats im paying is cheap for parts. im loving it. I wanna match port the TB to the mounting plate..

CAN the intake manifold be ported?? i havent looked into it???
my next thing is to look for some stock manifolds to just smooth out the openings on each. And then reinstall them with new gaskets for the hell of it. I think this would add some decent power..again i dont wanna go to nuts with the heads etc... just some little power, thinking a cool 15-20hp would be nice out of the whole package for her.

my question is along with what im doing...if anyone has anything to add would be great also....would this throw any engine codes?? im not too sure how set this cadillac is, i know on my regal, no codes are thrown when i did a bigger Tb, and heads with a mild cam. so im assuming the caddy might be different b.c its more computer controlled?? tell me what u think guys, everything is much appreciated to help me finish this project as fast as i can.
hopefully with what i do, no codes will be set.

thanx guys.

eldorado1
10-01-04, 08:45 PM
Instead of doing all that work, you could get some aftermarket cams, and get your 20hp easily. Heck, make it 75hp, doesn't cost any more. $150. Don't even have to remove the heads. Now, when you start talking adding power, you're going to need to alter the fuel delivery system to compensate for the more air that's going into the engine. Best way is to alter the fuel maps, but you may just be able to raise the pressure on your FPR, assuming it's a 95-99, it's just locktited in place. But then you'll be running rich at idle conditions, but the ECM may be able to compensate for that. It's just a pandora's box, it really is.

speedyman_2
10-01-04, 10:25 PM
Instead of doing all that work, you could get some aftermarket cams, and get your 20hp easily. Heck, make it 75hp, doesn't cost any more. $150. Don't even have to remove the heads. Now, when you start talking adding power, you're going to need to alter the fuel delivery system to compensate for the more air that's going into the engine. Best way is to alter the fuel maps, but you may just be able to raise the pressure on your FPR, assuming it's a 95-99, it's just locktited in place. But then you'll be running rich at idle conditions, but the ECM may be able to compensate for that. It's just a pandora's box, it really is.


75HP from a cam alone?? I might want to look into this. Who sells em?? And, what kinda torque curve will I have with a cam like that?? I too am wanting performance out of my N*. I already got the 75 HP shot. But, I would much rather have an "always-on" 75HP. I'm barely using the nitrous anyway, and I'm ready to get rid of it. Still, wondering about that supercharger kit. I dunno if it'll ever be done. :(

caddygirlny
10-02-04, 01:21 AM
ya see i know i can do cams etc...but i said i wanted to leave them alone..i wanna leave the motor cams stock, bigger cams throws codes, engine light b.c of misfires. i want to avoid this. besides im thiunking in terms of her tranny..i dont want her to blow it.
i know by doing litttle BS mods it wont kill her tranny...this is why im interesting in cleaning up some of the ports, and smoothing ou the manifolds and TB to match port. air will flow nicely.

i just wanna know if i do all this, will this throw a code or not...and what do i do exactly to not throw a code if i do this??

eldorado1
10-02-04, 10:15 AM
ya see i know i can do cams etc...but i said i wanted to leave them alone..i wanna leave the motor cams stock, bigger cams throws codes, engine light b.c of misfires. i want to avoid this. besides im thiunking in terms of her tranny..i dont want her to blow it.
i know by doing litttle BS mods it wont kill her tranny...this is why im interesting in cleaning up some of the ports, and smoothing ou the manifolds and TB to match port. air will flow nicely.

i just wanna know if i do all this, will this throw a code or not...and what do i do exactly to not throw a code if i do this??

The 4t80e tranny is rock solid. I would not hesitate putting 400hp with 400ft/lbs of torque through it (stock). More if it was modified with better clutchpacks, higher pressure, etc. The 4t65e's that are in the grand prix and what not are of a similar design, and they are always modding those superchargers with smaller pulleys and nitrous and god knows what else. They're not bulletproof, but I'd say you can get by with 150% of the input torque before you start running into wear/life expectancy problems.

Now, as to whether it will throw a code... Probably. Depending on how much it changes the flow characteristics, you could be running so lean that the ECM can no longer compensate for it in closed loop. However, there is a solution... The fuel pressure regulator is adjustable from the factory. It is just locktited in place. Doing a run on a dynojet with a wide band o2 sensor, and adjusting your FPR accordingly, should make it "okay". Not great, but better than burning a hole in your piston from running lean ;)

eldorado1
10-02-04, 10:16 AM
75HP from a cam alone?? I might want to look into this. Who sells em?? And, what kinda torque curve will I have with a cam like that?? I too am wanting performance out of my N*. I already got the 75 HP shot. But, I would much rather have an "always-on" 75HP. I'm barely using the nitrous anyway, and I'm ready to get rid of it. Still, wondering about that supercharger kit. I dunno if it'll ever be done. :(

Check out chrfab.com. You'll lose torque down low, and gain HP up top.

caddygirlny
10-02-04, 02:58 PM
thanx eldorado, good to know about the adjustable fuel regulator.
i own a 98 regal GS supercharged, after about 300 to the wheel hp the input is done froma launch from zero overtime. i blew my 4t65e. my car is mid 12's to low 12's depending on how cold it is. So i knew my GF 4t80e was kinda similiar, i just fear for her burnin the clutches and snapping the input shaft. besides running cams...like in my car, throws podes that u need a custom PCM to clear the code permanantly, plus its big money.
the porting i can do and re install myself, and its a safer bet for a few good horses IMO. i dont wanna go overboar,d i just wanna squeeze out a few horses from the air flowing in more smoothly.

sO ITS A DONE DEAL THEN,
thanx fellas ;D

danbuc
10-02-04, 05:41 PM
CHRFab's cams are reground for higher intake lift and duration. They can custom grind them for you depending on whether you want more torque, more hp, or a little of both. The only problem with buying even the 272 degree cams is that the cam position sensor might have difficulty judging the position of the cam lobes plus you would have to adjust the timing.

I am in the process of trying to figure out if you can change to the 272 degree cams from the 266 degree cams(intake on L37 northstar-300hp) without any major modification. I believe that 272 is possible without having to reprogram the computer(which I might add at this point is impossible) to tell the cam position sensors to recognize the additional lift and duration of the new cams. Since its only an extra 6 degrees, you could probably get away with it. I'm calling CHRfab on monday to speak with them about the cams and I am aslo calling my dealer to ask them how far you can go with higher lift cams before you create a problem for the engine.

Other than that, porting the heads will not really do anything unless you feel like loosing low end torque and only gaining hp at high RPM's(around 5000 and up). For any real hp/torque gain you have to do some mechanical work to the engine and open up the exhaust. I already have the Corsa system on my '98 STS, which Corsa dyno tested at around 20 extra hp and around 10-15 lb/ft of torque. If you increase exhaust flow, it will add to whatever you do to the engine, whether it is something like an airfilter, or internal modification.

I should also mention that if the cams do work, I would only use them on the L37 engine(STS,DTS,ETC) because its only 6 degrees difference. If you have the LD8 engine which has only 244 degrees of lift(SLS,DHS,Deville,ESC) its less likely to work do inpart to the 18 degree difference between its cams and CHRFabs base cams. As soon as I find out, I'll post my results.

danbuc
10-02-04, 05:46 PM
Porting the intake manifold is possible but very tricky. It is made out of a composite plastic which will not react the same way as metal would when grinding and smoothing out the openings. I actually wanted to try that myself but never got around to it. If you did that and opened up the exhaust, you would probably start seeing some real gain in performance. Goodluck with the car. ;)

Anthony Cipriano
10-02-04, 10:47 PM
my GF got her 99.

I already bought her a pair of 4.6L cylinder heads, full with rockers , cams etc...

stainless steel valves

i picked up the intake manifold with the TB at a junkyard with injectors for I wanna match port the TB to the mounting plate..

CAN the intake manifold be ported?? some stock manifolds to just smooth .


A question based on your comments above. What year were the heads you got? If they have "rocker arms" like you describe then they are heads from a 2000-later engine. The 93-99 cylinder heads that fit the 99 your girl friend has do not have "rocker arms". They have direct acting bucket cam followers.

Stainless steel valves? The OEM valves are stainless steel. Don't know what you are planning on gaining there.

The intake manifold is plastic and is very thin so "porting" it is risky at best. By the way, only an intake from a 95-99 will fit the 99 your friend has. If you have one from a 2000 or later it wont fit.

If you want to work on the intake the real thing to do is to cut a hole in the bottom of the manifold on the underneath surface. This will just be an access hole so that you can reach the plenum inside and smooth out the entrances to the various runners. After doing this you will have to "patch" the hole you cut with a formed piece of aluminum, RTV and hi-lo plastic screws.

Extrudehone the exhaust manifolds for best results.

caddygirlny
10-04-04, 07:36 PM
for the 99 STS....The cylinder heads i purchased have direct acting buckets, but they are not the higher lift STS cams. my original ones will bolt right in though. right??
so then the heads should work the same ....

danbuc
10-04-04, 08:58 PM
I have been informed by CHRFab that the 272 degree cams will work just fine in a stock northstar. Anything jigher than that should only be used in a car with a manual transmission. For the 4T80E, the 272's will be fine. You do have to buy the heavy duty valve springs for it though because of the higher cam profile. I also spoke to the service manager at my dealer down here in PA and asked him about possible problems with the cam position sensor. He said that the larger cams would have no negative effects on the sensor and that it would not throw any codes. I'm looking to buy a cheap set of heads on ebay and sending in the cams so I can get the new ones. CHRFab also said that it doesn't matter whether you have the LD8 motor(275hp) or the L37 motor(300hp). I hope this clarifies the issue about the cams ;) I almost forgot, the cams they sell will only work on the 1994-99 northstar engines.

foo
10-04-04, 09:27 PM
Why wouldn't a cam from a 2000 work in a 99? odd.. also what in the WORLD does it matter if the transmission is manual or automatic for a CAM? I've never heard that before :/

Anthony Cipriano
10-04-04, 09:48 PM
Why wouldn't a cam from a 2000 work in a 99? odd.. also what in the WORLD does it matter if the transmission is manual or automatic for a CAM? I've never heard that before :/

The Northstar was significantly redesigned for the 2000 model year. The cylinder heads changed significantly. The cams went from direct acting flat follower tappets to a roller rocker arm setup. They're not interchangable. The cams between a 93-99 and and 2000 and later are completely different ie. profile, material, etcetera.

The point about the cams working with an automatic or manual transmission is that the power characteristics of the higher performance cams causes a significant loss in lower end torque to achieve the greater hp on top end. With an automatic transmission (without significant modifications and a high stall torque converter) the car will likely be slower with the greater horsepower cam as it can't get the RPM to the powerband off the line with the automatic. This is a pretty heavy car with an automatic so losing low end torque is going to slow the car down a lot. With a manual transmission the driver can "drive around" the loss of low end torque by keeping the RPM high and slipping the clutch.

CHRFAB makes a lot of parts for sand cars that use manual transmissions and low gears and the cars only weight 1000 pounds or less. You can get away with losing a lot of low end torque to get the high revving power in that type of car. The same mods do not work on a heavy automatic transmission passenger car.

Technically, the cams will run the engine with an automatic. That has no bearing on whether the cams will open the valves and make the engine run. It's just how it runs that's being discussed. You wont be happy at all with a big cam in a small displacement engine in a heavy passenger car with an automatic.

Case in point. One poster this forum put the 300 HP L37 cams in an Aurora 4.0 liter. On the dyno it looks like a good swap with the engine gaining about 30 horsepower. The trouble is, the gain puts the peak power at over 6500rpm and the loss of low end torque is significant. He made the swap anyway and was so unhappy with the way the car drove he put the stock cams back in.

Shelby used the 4.0 Aurora in the Series 1 car that they developed and sold. That version of the engine was turned longitudinal and attached to a manaul transmission. The car weighed about 2600 pounds. Shelby put a modified version of the L37 cams in the engines. They made about 300 horsepower on the dyno and ran great in the cars. Why? The light weight car, manual transmission and low gears. They screamed in a Series 1 but were a turd in a production Aurora.

danbuc
10-04-04, 11:02 PM
Anthony, I don't know if this would change anything but the exhaust cam are also swapped for 272 degree cams. With a highflow exhaust system i.e. (Corsa) would that even out the power band at all, or would it still be to high. The guys over at chrfab have these cams in a few of their cars and they said that they run great. They are regular street cars too. They also mentioned that they put similar cams in a buick and it ran great too. If anyone wants to call them, they can give you much more detailed info on how they affect performance of the car. The number is 760-451-8796. This is a part of what it says on their pages about the cams- (For the normally aspirated engines, we have 5 grinds from mild to wild. These cams will still make enough vacuum to operate your power brakes, etc. We also set up the intake centerline a little differently to obtain more "torque" or more power.) You can basically customize how you want the cams setup. You have to speak with them about that though

Night Wolf
10-04-04, 11:23 PM
How much does of a set of the 272* cams run? (with the needed springs)

danbuc
10-05-04, 12:44 AM
After sending your old cams in(or a set from another set of heads) the four cams are $450 plus $150 for the springs. If you don't have a set of cams to send in first, its another $400 which you get back when you send them your old cams.

Anthony, chrfab runs 700 R4 "automatic" transmissions in there sand cars. Although they are more of a higher performance tranny, they are automatic none the less. Just thought I'd throw that in.

Anthony Cipriano
10-05-04, 11:00 AM
Anthony, I don't know if this would change anything but the exhaust cam are also swapped for 272 degree cams. With a highflow exhaust system i.e. (Corsa) would that even out the power band at all, or would it still be to high. The guys over at chrfab have these cams in a few of their cars and they said that they run great. They are regular street cars too. They also mentioned that they put similar cams in a buick and it ran great too. If anyone wants to call them, they can give you much more detailed info on how they affect performance of the car. The number is 760-451-8796. This is a part of what it says on their pages about the cams- (For the normally aspirated engines, we have 5 grinds from mild to wild. These cams will still make enough vacuum to operate your power brakes, etc. We also set up the intake centerline a little differently to obtain more "torque" or more power.) You can basically customize how you want the cams setup. You have to speak with them about that though


Yes. Thank you for the update. The cams might work fine if you're willing to live with the loss of lower end torque and/or work around it with a high stall converter. Several folks have used the higher stall Yank converter with excellent results. I know from dyno work with the L37 cams that the horsepower peak is at 6000-6200 so any more cam is definitely going to push the peak power up higher in RPM so you will have to shift higher to take advantage of it.

Like any modification, changing the cam events must be treated as a system approach. Just changing the cam alone will rarely give positive results in a heavy car with an automatic. With other changes it is possible I suppose to make a bigger cam work but it is not simple. I would spend the money on the higher stall torque converter first as it will certainly be necessary with the bigger cams and it will be the most bang for the buck that you can spend on the FWD Northstar package for performance whether you go with a cam or not.

It's like porting heads or anything else. If you test the cams with ported heads and a bigger exhaust and throttle body the look like they make more power but without all the parts the cams alone (or throttle body or other single mod) does not do much. It really takes a whole system approach. Just because a horsepower gain is quoted for an optimum package does not mean that the same gain will be evident on an otherwise stock engine.

Adding more cam to push the horsepower up will almost without fail cost a loss in low end torque. The torque can be improved with more compression but it's always going to suffer all other things being equal. The cam events really govern were the engine will have the optimum pumping efficiency relative to RPM. Changing the cam can move the torque/power peaks up and down the RPM scale but it doesn't really "create" anything.

danbuc
10-05-04, 11:14 AM
I called them again today and spoke with some woman who yealled at me when I asked about the cams. She said it wa a stupid idea and that I would not get anything out of them. Then she said that the reciept is "stamped" non returnable, so if I couldn't use them, I'd be up s**t creek without a paddle. That pretty much what she said. Even if they did work fine, I have no intentions in dealing with a person like that. I'm moving on to something else. :annoyed:

Anthony Cipriano
10-05-04, 03:45 PM
I called them again today and spoke with some woman who yealled at me when I asked about the cams. She said it wa a stupid idea and that I would not get anything out of them. Then she said that the reciept is "stamped" non returnable, so if I couldn't use them, I'd be up s**t creek without a paddle. That pretty much what she said. Even if they did work fine, I have no intentions in dealing with a person like that. I'm moving on to something else. :annoyed:


She told you it was a stupid idea because it is. You don't want to put those cams in a production street car because it will slow down. Do you really expect someone to take back a used cam? That's why you'll be up s**t's creek without a paddle when your car slows down.

Listen to "her" because she knows what she's talking about and forget the cams unless you're really building a monster. The girl you were talking to knows far more about cars and engines than you do. You should listen to her.

eldorado1
10-05-04, 08:49 PM
Anthony makes good points. The torque converter is the auto tranny's "clutch". Getting a looser converter with a higher stall is similar to dropping the clutch at higher rpms in a manual. It could mean the difference between a "slow, soft start", and "whoa, better ease off the gas so I have some tire left". BUT - on the stock computer, I can say with almost certainty that it will set a transmission code. Doesn't the 4t80e computer monitor torque converter slip through the input shaft speed sensor and driveshaft speed sensor?

Anthony Cipriano
10-05-04, 09:20 PM
Anthony makes good points. The torque converter is the auto tranny's "clutch". Getting a looser converter with a higher stall is similar to dropping the clutch at higher rpms in a manual. It could mean the difference between a "slow, soft start", and "whoa, better ease off the gas so I have some tire left". BUT - on the stock computer, I can say with almost certainty that it will set a transmission code. Doesn't the 4t80e computer monitor torque converter slip through the input shaft speed sensor and driveshaft speed sensor?



No, not exactly. The PCM monitors transmission input shaft speed vs. Engine RPM to determine slippage across the torque converter. This is monitored but is only used to determine if the torque converter clutch is operating correctly. A high stall torque converter will have no effect on operation of the torque converter clutch. When it applies the torque converter will lock up no matter what the stall speed is. If performance is the main concern the torque converter clutch can just be eliminated electrically so it never applies and that would not set any codes.

danbuc
10-05-04, 09:20 PM
I got it now, thanks for clarifying my foolishness Anthony . I was curious about high stall torque convertes though. I have heard people talk about them, and even some have said that they have them in their cars. Does it really make a difference? I would really like to know, and if it does, how can I get one and install it. Any info on this would be great. Thanks.

Anthony Cipriano
10-05-04, 11:28 PM
Yes, a high stall torque converter is the single biggest bank for your buck if you are interested in acceleration. That would be the first thing I would do with a Northstar package is to put a 3500 stall speed converter in it. There are quite a few previous posts on this subject.

caddygirlny
10-06-04, 12:04 AM
the cylinder heads i picked up do not have rockers. The cam is direct acting on hydralic lifters, and they are directly interchangable with a '99.
So once i port them, its just a simple swap, and im good to go. so these heads would work.

caddygirlny
10-06-04, 12:07 AM
hmm and if i were to get a higher stall converter in the N*, id might as well get a rebuilt tranny. stronger 4340 input shaft, some type of high energy clutches if they offer them for the 4t80e...and my tranny will be stronger...and id just hope the stater wouldnt break in the converter.

so for this off the line power, its big money IMO.

JaxxMan
01-05-06, 12:01 AM
Adding more cam to push the horsepower up will almost without fail cost a loss in low end torque. The torque can be improved with more compression but it's always going to suffer all other things being equal. The cam events really govern were the engine will have the optimum pumping efficiency relative to RPM. Changing the cam can move the torque/power peaks up and down the RPM scale but it doesn't really "create" anything.
You mentioned adding more compression might get back some of the torque lost by the bigger cam. In your opinion what kind of a ratio are we talking about ? 11:1 - 11.5:1 or is that going to make all other things suffer as you stated.
I ask only because Chrfab states they offer any ratio.
Your posts are very appreciated, I've learned a lot Thx

eldorado1
01-05-06, 10:57 AM
Good luck finding 100 octane when you're stranded...

JaxxMan
01-05-06, 01:14 PM
Ultra 94 fuel is sold in my area and will run 11:1 no problem.
Interesting read: http://www.powellmotorsport.com/ultra94.html
My long term goal is something completely different, Hydrogen.
Is has higher octane rating. The problem will be getting rid of the heat.
I have been watching this company for a while would like to implement their system when it's available.
http://www.switch2hydrogen.com
Very cool concept!

I should add that they recommended the Hydrogen conversion is only for engines with no higher than 9.5:1 ratio.
New pistons from CHRFAB to put in a Project engine.

94CaddyConcours
01-05-06, 03:55 PM
My long term goal is something completely different, Hydrogen.
Is has higher octane rating. The problem will be getting rid of the heat.
I have been watching this company for a while would like to implement their system when it's available.
http://www.switch2hydrogen.com
Very cool concept!

I should add that they recommended the Hydrogen conversion is only for engines with no higher than 9.5:1 ratio.
New pistons from CHRFAB to put in a Project engine.

Cool I can't wait for it to be available. But I tell you what they are not that cheap. One thing that I concern is that that you can run Hydrogen or Gasoline.

danbuc
01-05-06, 04:02 PM
Hmm...nothing like digging up an ancient thread:annoyed: CHRFab cams will NOT work properly in any Cadillac. The torque move way too high up in the RPM range, and trying to compensate that with higher compression on the N* is just stupid. I would imagine it would be done my machining the head surface slightly. A bigger lift cam, with less deck high, on an interferance engine is asking for trouble. I seriously doubt that the N* using the stock programming could run reliably if it had 11:1 compression on only 94. The ignition timing would have to be adjusted appropriately, which is prety much impossible to do without an aftermarket ECU.

JaxxMan
01-05-06, 04:39 PM
Hydrogen or Gasoline.
Early explainations on their website were: start the car on gasoline to get things heated to release the hydrogen from the tanks then electronically switch over making it a Bi-Fuel car. Making your own hydrogen is part of the kit's cost so you spend less on gasoline.
Perhaps this should have been in a new thread.

Aurora40
01-05-06, 06:00 PM
Ultra 94 fuel is sold in my area and will run 11:1 no problem.
I think it depends a LOT on the engine, not just the compression ratio. For example, GM's first DOHC V8, the LT5, can run 87 octane in spite of the 11:1 compression. However, look at the cooling system of the LT5 compared to the Northstar. It is much more complicated, all aimed at keeping hotspots down to allow the higher compression.

I think just tossing in 11:1 pistons or shaving the deck/heads might not necessarily work just by tossing in 94 octane. The 1st gen Northstar already recommends 91 octane with a 10.3:1 compression.

I'm just tossing that out, I'm no expert by any means. :)