How much boost on stock lower end is to much?
Thread Starter
11 Second Club
Joined: Oct 2002
Posts: 263
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From: North Carolina
How much boost on stock lower end is to much? A buddy of mine is looking at a 99 Z-28 with 40,000 miles on it. It has a ATI charger with dual aftercoolers and 9.5 to 10psi boost. The car also has a differnt cam(specs unknown) in it. I told him that sounds like alot of boost for a stock lower end but i could be wrong. Please Give me your 2 cents!
On The Tree
Joined: Nov 2002
Posts: 130
Likes: 2
From: Lee's Summit, MO
I'm no expert but I have been sitting on the fence for about two years about installing a ATI Procharger on my weekends only just for pleasure Camaro SS.
Everthing I have read in the last 2 years says on a stock internal engine not to run anything higher than 8 PSI. Now if you have it dyno tuned on the conservitive side of caution and don't drive it when the outside temperatures get above 90 degree's F. than maybe you could roll the dice and run 10 PSI.
Just my 2 cents.
Everthing I have read in the last 2 years says on a stock internal engine not to run anything higher than 8 PSI. Now if you have it dyno tuned on the conservitive side of caution and don't drive it when the outside temperatures get above 90 degree's F. than maybe you could roll the dice and run 10 PSI.
Just my 2 cents.
Thread Starter
11 Second Club
Joined: Oct 2002
Posts: 263
Likes: 0
From: North Carolina
I think you have to consider the hp the car put down also? This guy thats selling it claims well over 600hp with the car running in the low 10's 1/4 mile. that sounds suspect to me on a stock internals with just a cam. any thoughts?
I made 521/504 at the wheels on 10 PSI and 587/532 at the wheels on 12 PSI a few weeks later on the street it went boom (broke a couple of ring lands).
It may be 600 hp at the crank (475-500 at the wheels). I agree with above...8 PSI and a conservative tune is safe. It gets risky as you go higher than that.
Mark
It may be 600 hp at the crank (475-500 at the wheels). I agree with above...8 PSI and a conservative tune is safe. It gets risky as you go higher than that.
Mark
I ran 12psi on my stock bottom end most of a season. Made over 600rwhp and went high 9's in a 3500lb car. There was not a thing wrong with the motor when I pulled it. Tuning has everything to do with it though. It can be done but I wouldn't consider it safe.
Originally Posted by TwnTrboCE
I ran 12psi on my stock bottom end most of a season. Made over 600rwhp and went high 9's in a 3500lb car. There was not a thing wrong with the motor when I pulled it. Tuning has everything to do with it though. It can be done but I wouldn't consider it safe.
Originally Posted by TwnTrboCE
I ran 12psi on my stock bottom end most of a season. Made over 600rwhp and went high 9's in a 3500lb car. There was not a thing wrong with the motor when I pulled it. Tuning has everything to do with it though. It can be done but I wouldn't consider it safe.
I agree Its all in the tuning. I'm staying at 8.5# and just under 600rw
till I do the shortblock. (did 7500mi so far) Also make sure your fuel system is up to the task, If it leans out on the top end...
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I think 9 psi intercooled works fine. I think that 12 psi intercooled could be on the edge for pump gas. I think 500rwhp is doable, and anything above that requires even more attention to your tune, inlet air temps, and efficiency of your intercooler.
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Hey Mike.. just curious if you were using the stock maf? If so then you were obviously outflowing it... did you only make changes to compensate for it in the PE vs rpm? What type fuel and fuel system? What AFR were you tuning for? I was around 10.5-11.1 w/o alky injection, didn't remove and fuel, just added methanol on top of that on pump gas.. and 13 degrees peak torque, 16 peak hp.
Thanks for any input,
-Jarrod
Thanks for any input,
-Jarrod
U dont need to run alot of boost to make the power.... Im running 8psi but seeing 548rwhp 500rwtq with 19 degree of timing. Its all in the setup. U can get close to 600rwhp with 8psi if done right and thats what im planning to do before i increase the boost.
Originally Posted by RICE ETR
Hey Mike.. just curious if you were using the stock maf? If so then you were obviously outflowing it... did you only make changes to compensate for it in the PE vs rpm? What type fuel and fuel system? What AFR were you tuning for? I was around 10.5-11.1 w/o alky injection, didn't remove and fuel, just added methanol on top of that on pump gas.. and 13 degrees peak torque, 16 peak hp.
Thanks for any input,
-Jarrod
Thanks for any input,
-Jarrod
I was running it on the lean side. Was spinning it to 6800 also. From what I remember timing was around 20+/-.I wouldn't recommend doing this though.
Stock maf. Tuned in PE vs rpm table. I was running Sunoco 104 unleaded. Had one intank and one external Walbro running thru the stock lines and rails. With 42lb injectors. I was running it on the lean side. Was spinning it to 6800 also. From what I remember timing was around 20+/-.
I wouldn't recommend doing this though.
I wouldn't recommend doing this though.
Thanks for the info!
where any of you guys who broke ringlands running any type of logging software at the time? Do you know if it saw any knock (the ECU, not your ears).
Doubling the output of a motor only stresses the internals about 15-20% more than stock, but if you detonate i can be in the 1000% range. The motor will get tired faster though making more power and running it hard.
Doubling the output of a motor only stresses the internals about 15-20% more than stock, but if you detonate i can be in the 1000% range. The motor will get tired faster though making more power and running it hard.
yeah, i know, i fear it. Thats why I was asking. I've tuned a lot of boosted cars, but they are usually built to some level. I always tune safe on a stock motor. My target a/f on the street is 11.0-11.2 with conservative timing.
I just picked up my 2000 SS STS car today. I'm retuning it tonight to help with some of the cam surge it has at lower RPMs. At 5 psi it's out of fuel at 6000 rpms (leans out to 12.1). I'll hopefully be throwing the walbro in it this weekend, next weekend at the latest. Until then i'm just taking it easy.
Intercooler will be going on before summer, will run 7 psi max on pump.... if it can do it in our vegas temps. Ran 5psi ok, but could barely get any timing in it during 100+ days. IATs were as high a 170.
I just picked up my 2000 SS STS car today. I'm retuning it tonight to help with some of the cam surge it has at lower RPMs. At 5 psi it's out of fuel at 6000 rpms (leans out to 12.1). I'll hopefully be throwing the walbro in it this weekend, next weekend at the latest. Until then i'm just taking it easy.
Intercooler will be going on before summer, will run 7 psi max on pump.... if it can do it in our vegas temps. Ran 5psi ok, but could barely get any timing in it during 100+ days. IATs were as high a 170.