LQ4 turbocharged

[ute 400]

Hi guys my name is Manuel im from Australia ,Sydney,I have a Holden commodore ss with a genIII 5.7 engine.
I reacently put a intercolled turbocharged kit,(garrett gt 3540rr turbo) running 10psi,and while it was getting dynoed it opened a crack in the bore.I previously had a supercharger on it which ran 10 psi aswell for 1 year,i had problems with the previous tuner with detenation,lots of detenation,i think iy weakend the bore.
I sold the supercharger because lt kept on throwing belts,so i went turbo instead.

My question is i have now a 6.0litre iron block with 317 casting heads and dished pistons from the lq4 engine,i bought all the parts separate,block,pistons,heads,with the crank and the rest from ls15.7 engine.
At the time i cant aford forged internals which would be the best for my application.but i thought going this way i could drop the comp.
In Australia lots of guys are running these same turbo setups on standard ls1 5.7genIII with standard comp.(10.1) on 10 psi.

Are the dished pistons from the LQ4 engine stronger than the ls1 5.7flat pistons?
The dished pistons have a thicker ring lang ,and the piston itself is chunkier,would this make it stronger?Being from a truck engine plenty of torque.
The reason im asking these questions is because not many people here know about these truck engines,and my mechanic thinks that the pistons look weaker than then ls1 5.7 beacause the casting on top of the dish looks rougher.
Ive being told here that all Ls1 genIII pistons are made of same material,is that true?

Could some one let me know what they think.

[1slow01z71]

Ill put it this way there a re few guys running mid 500 rwhp on stock LQ4s. I wouldnt worry about it. I have lookied at all different stock GM pistons and they all seem to be made of the same stuff, the LQ9 pistons ahve a coating on them so they look a bit different but under the wrist pin area they look the same. You cant afford 500 bucks right now? If it was me I would wait and buy the pistons there are plenty of manufacturers out there that make replacement 6L pistons that are forged and will net a much stronger engine.

[RedHeartbeat]

Save your money and do it right the first time. Get some forged turbo pistons. Wiseco make a good forged budget priced piston. Get quality rings to go with it. You don't have to change the crank, just get the pistons installed before you swap it in. Forged will go a long ways for reliability.

[bud8fan]

yep what they say...welcome to the site.....

[ute 400]

<div class='quotetop'>QUOTE(1slow01z71 &#064; Sep 23 2006, 10&#58;37 PM) [snapback]66255[/snapback]</div>

Ill put it this way there a re few guys running mid 500 rwhp on stock LQ4s. I wouldnt worry about it. I have lookied at all different stock GM pistons and they all seem to be made of the same stuff, the LQ9 pistons ahve a coating on them so they look a bit different but under the wrist pin area they look the same. You cant afford 500 bucks right now? If it was me I would wait and buy the pistons there are plenty of manufacturers out there that make replacement 6L pistons that are forged and will net a much stronger engine.
[/b]

Thanks guys.

All standard 5.7 ls1 genIII engine ,turbocharged are all running about 330-400rwkws and no one has had any problems on 10 psi.
The problem is that the engine has already being built and in the car ready for tuning soon.To pull engine out would cost to much im on tight buget.
Ive been told that there is no point having forged pistons if your leaving the conrods standard.
If the standard ls1 flat top pistons ,standard comp. engines are running fine on 10 psi,wouldnt i be safer with lower compression,that they are?

I know that forged is the way to go,but could some one tell me if the LQ4 pistons are stronger or made out of the same material as the ls1 5.7?


Cheers guys i appreciate you helping me.

[1slow01z71]

Any time you can lower the CR wit boost do it. Like I said in my first post tehy look to be made out of the same stuff. The stock connecting rods can handle alot. There are people putting 800rwhp+ down with stock con rods. Also with forged pistons you will be able to drop the CR alot more than the -7.1cc dish the LQ4 pistons have.

[RedHeartbeat]

The lower the static compression ratio, the higher the boost you can push through the engine. With stock LS1 compression, increasing to 10 lbs of boost is like running 15:1 compression. If you drop the compression down to 8:1 you can pretty safely run 15+ pounds through it. The whole point of going with a turbo is to push more fuel and air through the engine. There are all kinds of people running 20+ lbs of boost in a low compression setup, doing it daily and on high octane 91-93 versus starting out with stock compression and having to run racing fuel to prevent detonation.

[DBYRD]

can u post a pic of the car and engine, isnt this australias version of the GTO? seems they make an el camino-like version of this too? SWEEEEEEET&#33;