What's the most boost you can add to an LS1 (2001 C5) without modifying the internals?
Also this might be a dumb question, but what is the difference between the C5 and Z06 in this year. Specifically I mean the engine, does the Z06 have higher compression, and thus less tolerance for high boost?
Just curious; What some of you guys have got for dyno numbers on a stock motor, and at what level of boost?

 

Heads and cam are the differences in the C5 and Z06. You can safely run about 7-8 psi on stock internals with a good tune.

 

With better gas or meth you can turn it up a little more....

But 7# is a safe number on a healthy motor.

G

 

We typically set these engines up for 8 psi of boost. Once you get use to it, you're going to want more boost, but I don't advise it until you add better rods and pistons. Bob

 

Is it boost alone that we you are worried about or does horsepower and torque factor in at a given rpm ?

 

I've heard 550RWHP is about the safe limit before, after that it's just the luck of the draw.

 

LS1 is 10.0:1 compression and the LS6 (all years) is 10.5:1 so the LS1 can take a tad bit more boost than the LS6. I've always heard 7-8lbs is the max safe amount.

A basic centrifical supercharger kit with longtubes will make 530-540 rwhp on a LS6 w/o meth.

 

I had my old stock Ls6 with a Vortech SC Trim at 9.2lbs and it made 504 rwhp on a mustang dyno. No issues at all.

 

Hoping to get to 9-10lbs on a stock LS6. Meth & stronger springs.

 

This question comes up alot! Maybe it should be a sticky? I'm at 12psi on a stock LS6 with meth. That's on 92 pump gas, thru the OEM cats and OEM fuel pump. The dyno sheet is in my signature. They can take more than people think.

 

Is that your current turbo setup in your avatar? If so do you have any more pictures?

 

You've just been lucky, a lot of others' have not had such good luck. You are the exception, not the rule.

 

If its a TT or roots SC I'd forge it for sure at 10 lbs. If its a Centrifugal SC you may have more latitude. Still, you are playing with fire IMO

 

I have read so many owners posting about engine damage at around 575 rwhp

 

You've likely gobbled up a lot of info but in case you haven't read basic forced induction I would start there. Not saying you haven't nor you sound like you haven't. I think it's a must for anyone running a FI motor. I think it can help you understand why you need certain things and allows you to really understand why your engine builder and tuner is doing all that expensive stuff to your car.

FI motors have quirks that NA motors don't. One is heat and another is cylinder pressure affecting detonation and preignition. There's lots more but basically it's still an air pump esp at low numbers like you're running.

The most important thing is a tune then having the right air/fuel mixture at decent temperatures delivered at the right times. As you go up in pressures you need better internals and a way to get your IATs down and as always not detonate which is too complicated for me to talk about.

I think you're ok for awhile if you stay at that pressure, keep good fuel in the car and keep the car tuned properly to run under boost. One bad injector can lean you out and ruin your day just one thing that can go wrong esp without knock sensors and all the rest of the tune looking for all the bad and good things its supposed to be looking for and then doing corrective things to keep you intact. Any more pressure than you're running needs lower CRs, lower air temps, better rods/bolts/pistons, the proper cam and yada yada yada.

I'm not qualified to sermonize so I'd start there and just ask questions.

 

I ussually recommend 8lbs for a stock motor, 10-12lbs with valve springs. My personal Vette ran 14lbs on the stock motor with springs.It's all in the tune.

 

No - that's my race car. 94MM single front mounted turbo, 427 warhawk block and heads, hogan intake, 2 speed powerglide. Cage/chassis certified to 6 seconds. That car is at Carroll's rod and racecraft/neverlift being finished. Look in my pictures under my avatar

The car I am referring to is a 2003 Z06 with a rodney auto level 5 tranny conversion and a novi2000. ECS is finishing it up now and we put a meth kit in and swapped the springs. Also, will use 100 octaine plus when we run at the track. As slowhawk says - its all in the tune

 

I ran 10#s and made 641rwhp on the stock head/bottom end without meth or alky on 91 octane. That setup felt like it would have lasted forever had I not bought a Katech 402.

It's all in the tune. Listen to Bob as he's answered a lot of questions of mine.

 

I agree, it is mostly the tune. Hell, after 200+ ¼ mile passes, I finally broke a ring land with 665rwtq, sprayed bone stock LS6 though. It still shows what Chris said, that these motors can take a lot more than people think. By the way, I have personally seen Chris run his numbers, dyno and the strip, the car is a true beast.
Robert

 

05 bottem end(LS6)(stock with studs), no meth,....7.5psi 615rwhp 565 ft-lbs. Racetronix, Siemens 60's....and a great tuner.