Max boost on stock LT1
 

Bought an ATI procharger kit, and wanted to know what the max reliable boost would be. Planning on running 8 psi from the d1sc twinhighflow intercooled kit. I have heard lt1 pistons are crap and bla bla bla..mods in sig...lemme know!! :death:

Re: Max boost on stock LT1
 

You heard right...

Stock + reliable + boost = 0 psi

If everything is working right, tuned perfectly, and you pray vigorously...you'll be fine...for awhile. Some people get 400 miles while others get 40k+ miles on stock motors. Mine lasted about 20k.

You can add another certainty to your life...death, taxes, and an eventual membership in the rebuild club. :cry:

But it's still worth it...blower whine rules! :bow:

Re: Max boost on stock LT1
 

I agree with the above post. But 6psi is RELATIVELY safe on a stock LT1. The power gains from 6psi are not huge, however. Partly because even if you retard the timing and run it rich (which in and of themselves decrease power) you will have some detonation on pump gas. This will lead to power loss directly as well as knock retard, further decreasing hp. Overall, I am not sure adding a blower to a stock LT1 is worth it. Unless you are planning on rebuilding anyway!

Rich

Re: Max boost on stock LT1
 

Save yourself the time and labor....the ringlands on the stock pistons will give up the ghost, just build it right to start with, even if that means you will have to wait a while to afford it. It will be worth the wait!
-Michael

Re: Max boost on stock LT1
 

Not a question of if you will break a piston but when. I got about 2K miles on 8 psi procharger until I started blowing smoke out the breather and tailpipe. Eventually took the supercharger off and sold it. I had a lot of problems with that supercharger kit anyways. I bought it when they first came out. It leaked oil, they machined the bracket wrong so the belts where mis-aligned, then the thing seized up on me in the middle of nowhere Arkansas at two in the morning. This happened 1 month after warranty expired and they charged me over $1,000.00 to repair the stupid thing(and it still leaked after that!!!). Maybe they are a lot better now but I will never recomend them.

Re: Max boost on stock LT1
 

You're definitely going to want a more detonation resistant fuel than common gas station fuel; which is only available up to 94 (Sunoco Ultra)

If you race brackets, where they don't do fuel testing, then you can use Toluene (114 Octane) as a booster. (I get mine at Sherwin-Williams and use a 4:1 G/T ratio.). It IS safe for Cats & Ox sensors by the way. It's a pure hydrocarbon and wont hurt your car.
If you DO race in a class where fuel is checked, then you'll want to use race gas as a booster.

You see, there are two ways to kill an engine that are related to this question. One is to generate higher cylinder pressures than your engine can tolerate and exceed the elastic limits of your piston's top land. In the same category, you can also get metal fatigue even if you never go past those elastic limits.
The other way is to get into detonation, which not only takes your pistons right past their plastic limits, it takes them right past your oil pan's limits. ;)

If you stay out of detonation then you have a much better chance of running that 6-8 lbs of boost for a long time.

Having said all that, and hoping I got my terminology right, the suggestion from Mike & Rich; to build your engine right the FIRST time, is probably going to be your most cost effective option in the long run.

Re: Max boost on stock LT1
 

I don't have firsthand forced induction experience but from what i have read and learned from talking with guys that run FI, here is some advice, highest possible octane fuel a given, upgraded ignition like the new MSD or Crane HI-6S, upgraded fuel pump&injectors, water meth kit&a GOOD dyno tune and they say even with crappy CA 91 it should be fine :D Here's a link to a water/meth injection kit
http://www.aquastealth.com/browsepro...ction-Kit.HTML

Re: Max boost on stock LT1
 

I wouldn't do more than 8. Start saving for a motor.

Re: Max boost on stock LT1
 

heres the thing. I am in colorado, and my elevation is over 5000 feet. I have a MSD 6A box, 160 thermo, Fan switch, headers, catback, and 1.6 rr's. I have installed a walbro 255, and will be running with 42# injectors.I will be getting a dyno tune first and foremost, and will run with 2-3 degrees retard and a fuel air ratio of 12/1. Hope everything turns out. I will also post my rwhp numbers soon!

Re: Max boost on stock LT1
 

I would stay around 5psi. I made 340rwhp with 4.5psi of non intercooled boost, went to 7psi and motor started blowing smoke out the breather.
I ditched the blower and built a nice N/A setup. Wasn't planning on rebuilding my motor at 80k, but the blower thought otherwise.

Re: Max boost on stock LT1
 

I'd say get rid of the supercharger and get a good cam, heads and a tune! A guy I've raced 6 times with a stock LT1 TA has lost 6 times to my NA Trans Am. And the races were not very close either!!

Re: Max boost on stock LT1
 

since i am at 5500 feet elevation, 8 psi up here is 5ish psi at sea level because the air is less dense. I will have dyno tuning done, ignition retard, and fuel/air ratio of 12/1. Think i will be fine.