etbdmr12

how much psi can a stock ls1 take? 8-9?

anyone have a definite answer?

MY99TAWS6

iTrader: (3)

Depends on what turbo super..pounds of boost are not pounds of boost.Airflow is the determiner of power. Big turbo at 10psi puts out way more power than small turbo at 10psi. But generally if you must have psi numbers run 5psi and be conservative with stock compression heads. If you put on say 317s and drop compression can possilby got to 8 or 10psi again with your basic smaller single turbo like sts starter turbo type of thing.
Make sure your tune is close to perfect in terms of afr and timing. Too lean or too much timing boom boom on the stock ringlands..rebuld time then for sure.
Be conservative and stock engine can last. Have pistons in my garage from people that had various little stock motor accidents. One guy took out his pistons at 8psi on ati. Other guy had little boo boo with his greddy boost control on his lt1 sts car. Both lost ringlands and had to rebuild motor. expensive mistakes.Stock pistons suck.

Johnv

I don't think a given boost psi is a cutoff point for engine longevity.

I'm sure you could kill an engine with zerrow boost if abused or badly tuned, and another may run 15 psi with a good tune and sensible driving and live a long and happy life.

Personnaly i think HP is probably a better measure, and consider 500 rwhp to be pretty reliable limit with good supporting mods,good fuel supply and a solid tune.

But plenty will push harder without to much drama in the knowledge that a forged rebuild could be in there future

'Trust'

iTrader: (24)

I know of one locally a few years ago that was on 14psi, made 630RWHP on a very conservative tune but popped pistons occasionally. The guy owned a shop so he would just replace the pistons and bead hone. The goal was max power boost on a stock bottom end. That being said, I wouldn't go over 10 on a stock bottom end, and I'd prefer 8psi.

transamLs1

hey reza!

TransAmatt99

iTrader: (24)

Hey im just up the river from you a bit...But if you are talking super, I have a v1 vortech it put 12psi@6100=600rwhp on the stock bottom didnt blow anything but probably wouldnt last long. Ls2 403 in the works.

speeddemon651

iTrader: (8)

can't go wrong with 5 psi on a stock ls1

Compressor Surge

iTrader: (21)

Currently at 12 psi from a massive turbo on my 5.3......I'll let you know when (if?) it tosses it's cookies!

cbr600rx7

iTrader: (12)

It may have been said but this is asked a lot. There is no definite answer. A lot depends on what set up you run, How big is your Turbo/SC, what kind of cooler are you using, and a lot comes down to your tune. There are also a million other factors that go into it.

I would say 7-10 is what most guys running depending on there set up on the stock pistons but you will see a few guys running a little more and a few making good power on a little less.

Reject

iTrader: (24)

run 16# on the stock bottom end. TC76F1 turbo with 317's filling the slugs up top. i know it's going to blow up. it's nothing to be unexpected.... i'm just wondering when and if i'll have it on video

speeddemon651

iTrader: (8)

why is it you never seem to get the best carnage on video.

airforcemanss

iTrader: (23)

hey guys im about to buy 317's from the classified section and i was wondering what gasket would i use to lower compression? i plan on throwing on turbo kit on in a few months. i have a stock ls1 and i don't plan on putting a cam in at all when the turbo goes on. any info would be great. i don't know what these heads will drop my compression too

WS6Drop

iTrader: (10)

I think I would use a hp number rather than boost pressure.

airforcemanss

iTrader: (23)

anything over 600rwhp

LS1Silverado05

iTrader: (41)

Keep in mind that unless the rest of the car is already set up... you will probably need work in other areas of the car even at "safe" HP levels like 500...

Rear, Trans, Suspension.... Its fun to see what HP you can make, but its not much good unless it can 60' and pull down a nice timeslip....

That is unless you are the Dyno queen type...

dudeman

iTrader: (43)

soem gm mls gaskets should be fine. i think they are .053 thick.

i have heard 9.5 and 9.8, so somewhere around there. you can try to find a compression calculator.


or unless you do lots of roll racing!!!

sujomatt

iTrader: (7)

Yea i am running 317 heads with the GM MLS gaskets...

I have a very bad tune from a sponsor on here - it is set for 10 but it creeps to 11-12 psi and leans out viciously.

Even with that said and the occasional romp - its holding together just fine.

The only thing that has 'gone wrong' is an oil scavenge pump failing and 1 of the lifters ticks pretty hard now.

LS1Silverado05

iTrader: (41)

Thats not really the tuners fault is it? Did you have it dyno tuned at their facility or go mail order and expect it to correctly fuel your boost creeping motor?

sujomatt

iTrader: (7)

It was NOT mail order, and it was on THEIR mustang dyno that it was tuned on.

Yea has to be my cars fault - it not be the great tune when it goes 9.x:1 AFR when it hits boost and leans out to 12.9:1 a second later..

My purpose in posting that was not to bash the company - i was simply saying - our motors can handle a lot of abuse even with the psi around 10-12

ChevyChad

iTrader: (50)

Wow! this thread is packed full of complete garbage! Serves the OP right tho for not doing a search in the first place.