Safe amount of boost on a stock bottom end?
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From: TAMPA by way of MIAMI!!!
Safe amount of boost on a stock bottom end? My wifes uncle has a 2000 C5/A4 and is looking into boosting it. The car is low miles like 25k. He's been thinking about a Maggie well actually he's thinking Lingenfelter I know I can dupe that package way cheaper. But the question remains what can the stock bottom end take? The kit is 5psi but I am thinking 8-10psi intercooled of course. He doesn't drive it all that much and usually doesn't whip it too much.
I'm figuring for the price of the Lingenfelter kit I can do some headers and a cat-back plus a ported throttle body get her to about 550fwhp without breaking too much of a sweat.
Opinions, speculations, wild *** guesses, and even educated guesses are welcome and actually what I'm looking for. Thanks in advance.
I'm figuring for the price of the Lingenfelter kit I can do some headers and a cat-back plus a ported throttle body get her to about 550fwhp without breaking too much of a sweat.
Opinions, speculations, wild *** guesses, and even educated guesses are welcome and actually what I'm looking for. Thanks in advance.
http://www.exoticperformanceplus.com/hotCars.php?car=48
http://www.exoticperformanceplus.com....php?service=6
We typically shoot for 8 psi of boost with the ATI ProChargers. Bob
http://www.exoticperformanceplus.com....php?service=6
We typically shoot for 8 psi of boost with the ATI ProChargers. Bob
With more than 5 lbs of boost you are taking a chance. Too many cars have had problems with #7 going to lean and grenading. Some have made it to 8,000 miles, some to 15,000 and some to 20,000 before it happened. In every case it was # 7 and it usually took #8 with it.
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
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From: TAMPA by way of MIAMI!!!
Yeah I would like to do the whole motor but a rebuild is outta the question a cam change will prolly even be a stretch I don't think he's willing to go that far. But a pully change is more than poss what I'll prolly do is go with the standard pully until the rest of the mods are done and then we'll see about spinning the Maggie faster.
But guys keep coming with the opinions. Thanks.
But guys keep coming with the opinions. Thanks.
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From: TAMPA by way of MIAMI!!!
Originally Posted by Gordy M
With more than 5 lbs of boost you are taking a chance. Too many cars have had problems with #7 going to lean and grenading. Some have made it to 8,000 miles, some to 15,000 and some to 20,000 before it happened. In every case it was # 7 and it usually took #8 with it.
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
Is that with a centrifigal? Because I've heard of some guys having that same problem N/A (it might have something to do with the manifold) in the case of the Maggie you lose the manifold. That may fix the problem? I'm jest guessing here.
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You can always get away by running more boost on a Centri style SC than a turbo or a Roots style blower just because of the nature of how both produce boost. For example, I'm at 13psi now on the stock bottom end and only seeing an avg of 9psi from 3K to 6000 RPM. On a Turbo or Roots style car it will most likely have a higher number than that which means you want to dial the peak boost back to a safe level. Usually turbos make peak boost in the midrange and either hold it or drop by 1-2 psi by redline. Some of them starts dropping at the end of the run due to high backpressure. A roots style makes even a higher avg number than a Centri or a Turbo because they usually dont drop in boost pressure and hold it to redline while building almost full boost by 2-3K RPM.
So IMO a safe boost level on a LS1 (10.1 C/R) running a roots style blower would be around 7psi, Centri SC would be 9psi and 7psi on a front mount turbo or 8psi on a rear mount turbo. That is assuming the SC's flow 1000-1400 CFM and the Turbos are in the 60-67 range.
So IMO a safe boost level on a LS1 (10.1 C/R) running a roots style blower would be around 7psi, Centri SC would be 9psi and 7psi on a front mount turbo or 8psi on a rear mount turbo. That is assuming the SC's flow 1000-1400 CFM and the Turbos are in the 60-67 range.
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From: TAMPA by way of MIAMI!!!
So I think the Maggie is gonna be the way to go (he likes the look of the hood too..... Old school) it'll be a good foundation and will prolly be more than sufficient for him. That with some supporting mods (headers and full exhaust, ported or aftermarket TB) will do well hell you never know maybe I'll get him to do a head/cam change. But I can safely say he's not into rebuilding the shortblock.
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From: Ft. Irwin, California (But Virginia is home)
Originally Posted by Gordy M
With more than 5 lbs of boost you are taking a chance. Too many cars have had problems with #7 going to lean and grenading. Some have made it to 8,000 miles, some to 15,000 and some to 20,000 before it happened. In every case it was # 7 and it usually took #8 with it.
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
Also, many thought IC or tuning would eliminate the problems but evenually they were victims.
For longevity, go Forged....
Originally Posted by LSs1Power
You can always get away by running more boost on a Centri style SC than a turbo or a Roots style blower just because of the nature of how both produce boost. For example, I'm at 13psi now on the stock bottom end and only seeing an avg of 9psi from 3K to 6000 RPM. On a Turbo or Roots style car it will most likely have a higher number than that which means you want to dial the peak boost back to a safe level. Usually turbos make peak boost in the midrange and either hold it or drop by 1-2 psi by redline. Some of them starts dropping at the end of the run due to high backpressure. A roots style makes even a higher avg number than a Centri or a Turbo because they usually dont drop in boost pressure and hold it to redline while building almost full boost by 2-3K RPM.
So IMO a safe boost level on a LS1 (10.1 C/R) running a roots style blower would be around 7psi, Centri SC would be 9psi and 7psi on a front mount turbo or 8psi on a rear mount turbo. That is assuming the SC's flow 1000-1400 CFM and the Turbos are in the 60-67 range.
So IMO a safe boost level on a LS1 (10.1 C/R) running a roots style blower would be around 7psi, Centri SC would be 9psi and 7psi on a front mount turbo or 8psi on a rear mount turbo. That is assuming the SC's flow 1000-1400 CFM and the Turbos are in the 60-67 range.
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From: TAMPA by way of MIAMI!!!
Bryan okay I get what your saying make sense. My thinking is though GM will boost a 3800 with 5-7lbs out of the box sounds like a nice safe number right? But I know there are guys out there who claim they run 12psi + on stock short blocks (I think they are a lil crazy) but what I'm getting at is that the LS1 rods are supposed to be stronger and the pistons are similar and the crank is supposed to be stronger. Now assuming that I'm careful of detonation and don't go too crazy I would think 8psi would be cool. I am considering the higer static compression of the LS1. Also the Maggie (an Eaton) to me is gonna be reliable, the one on my Impalla SS (M90) seems pretty reliable and I've seen those motors with a schizz load of miles and they were running well (a lil down on power needed to rebuild the SC) so I'm thinking the rotating assembly of the LS1 is better and then the only question is the durability of the cylinder liners. With a proper tune 8psi should be good.......... I think.
Keep it coming guy's I appreciate the opinions.
Keep it coming guy's I appreciate the opinions.
Originally Posted by firefighter
Bryan okay I get what your saying make sense. My thinking is though GM will boost a 3800 with 5-7lbs out of the box sounds like a nice safe number right? But I know there are guys out there who claim they run 12psi + on stock short blocks (I think they are a lil crazy) but what I'm getting at is that the LS1 rods are supposed to be stronger and the pistons are similar and the crank is supposed to be stronger. Now assuming that I'm careful of detonation and don't go too crazy I would think 8psi would be cool. I am considering the higer static compression of the LS1. Also the Maggie (an Eaton) to me is gonna be reliable, the one on my Impalla SS (M90) seems pretty reliable and I've seen those motors with a schizz load of miles and they were running well (a lil down on power needed to rebuild the SC) so I'm thinking the rotating assembly of the LS1 is better and then the only question is the durability of the cylinder liners. With a proper tune 8psi should be good.......... I think.
Keep it coming guy's I appreciate the opinions.
Keep it coming guy's I appreciate the opinions.
Many people have bashed me about a turbo being better than the supercharger, so I guess I am going to find out. I bought an 06 GTO and I am going to install the ls1turbo.com.au twin setup. They are telling me it will be running somewhere between 7-9 lbs on my stock block. I am not changing the bottom end, so we will see if the proof is in the pudding.
Last edited by Bryan Wilkinson; Jun 2, 2006 at 06:31 AM. Reason: spell check
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From: TAMPA by way of MIAMI!!!
I don't argue the opinion on the turbo. Both methods have been used with lot's of succes by many OEM's with minimal problems. I personally like the Eaton/roots style SC because of sheer simplicity. Turbos are cool, and some of the fastest cars I've been in were turbo but all the owners eventually said the same thing, they were complicated to set up. I also think you have to know a little more to get a turbo to work right but once it does and you have it dialed in so that lag is minimal they run like hell. To me the Maggie is so simple to get going it essentially is like an intake swap set a blow of do a pully cange get it tuned drive the hell out of it. For this case I think the maggie is the answer it'll prolly be more complicated getting the hood prepped and the paint to match than it will be to install the SC itself. I would think about doing a turbo on a project car maybe the Monte in the sig but the Blazer is gonna stay N/A or maaaaybe do a Maggie on her cause there is no hood clearance issues from what I've been told.
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From: Elmhurst, IL (Chicago Suburb)
Originally Posted by Noyzee
i ran 10 to 13 psi on my stock motor for over 20k miles with not 1 issue.
No there you go, although this seems to be the exception on a stock cubed motor but we all no ITS ALL IN THE TUNE BABY!! Get it tuned by a PROFESSIONAL F/I LSX expert, don't get greedy on the boost, and you should live happily at 10lbs of boost if all is set up right.
I have pushed 4200 miles with 0 issues on my stock 10:5 to 1 LS6 motor in my Z06 but i keep the boost around 7 to 8 lbs on the street and have seen 10lbs on a few occassion!!
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From: East Side Performance! mASShole
Originally Posted by MTI 427 C5 Roadster
No there you go, although this seems to be the exception on a stock cubed motor but we all no ITS ALL IN THE TUNE BABY!! Get it tuned by a PROFESSIONAL F/I LSX expert, don't get greedy on the boost, and you should live happily at 10lbs of boost if all is set up right.
I have pushed 4200 miles with 0 issues on my stock 10:5 to 1 LS6 motor in my Z06 but i keep the boost around 7 to 8 lbs on the street and have seen 10lbs on a few occassion!!
I have pushed 4200 miles with 0 issues on my stock 10:5 to 1 LS6 motor in my Z06 but i keep the boost around 7 to 8 lbs on the street and have seen 10lbs on a few occassion!!
any all my stock parts looked perfect when i pulled the motor apart.
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From: East Side Performance! mASShole
Originally Posted by firefighter
This is the kind of stuff I was looking to hear.
