Wicked C5

So I guess the Gm Engineers are dumb to do 9:1 on the 6.2 LS9 Zr1. They should of just kept the LS3 10.7:1 and thrown the blower on it.

I also guess Wieco,Diamond and the other companies are silly to offer dished pistons to lower compression

I've been on here along time and have seen more of the Ls6 motors that blow up compared to the lower compression Ls1 gee I wonder why.

Yes it is possible to put a blower on a 11.1:1 motor but your chances of detonation go up as your PSI rises not to mention temperature and elevation changes.

My only point was you can sell your AFR's to pay for the labor in the end you will end up with a higher hp safer motor then running lower boost and keep the Afr's.

user_name

OEM's work under quite a few different terms when building their cars. They also run the AFR into the low 10's on the ZR1's. It is built way beyond safe.

Your chances of detonation at 11:1 are no higher than 10:1 with the right timing and octane.

As for dish pistons, I don't even see what point you are trying to make.

Point is, TONS of people are running boost on the higher comp motors. You can't run as much boost as you COULD on as lower comp motor, but most don't even push it with the lower comp motors. I'd throw 8-10psi on an 11:1 setup all day long with meth+93.

Wicked C5

Yes and many more Stock Ls6's with 10:5:1 go kaboom then stock Ls1's with 10:1:1 and even less with 9:5:1 like me. He is in California like me and we have crappy E15 winter blend gas currently with 91 octane but the methanol does help a bit.

user_name

No point in arguing with you. This is not what I have seen.

Shinobi'sZ

I would suggest two things that you could do.

1.) Take off your heads, keep them or save them and purchase some LS6 heads off of Ebay for $450-500. Send the LS6 heads to any reputable race shop...MTI, LME, Vette Dr's, ECS, A&A. etc and have them open the chambers up to 72-74ccs. This will drop your static CR down significantly...target should be 9.7-10.0 for a centrifugal setup..like A&A or ECS. It will probably cost you about $400-500 to have the heads transformed into blower heads.

2.) Do the same thing with you existing heads and only spend $400-500.

You will be able to safely run your motor at a lower compression ratio and with a good tune you should be able to run 10#s boost easy and make 550-600 rwhp.

I would recommend West Coast Cylinder heads. Richard (WCCH) did my stock LS6 heads 6 years ago. I am still using them...I have only made 850 rwhp though.

Just for reference I ran 10#s boost with my D1 initially on my stock LS6. I had low miles on it...first time I had detonation underboost I lunched the motor and broke 5 piston ringlands. You can certainly run your motor until it pops...but you run the risk of damaging (scarring) the cylinder walls and not being able to re-use the block. It doesn't happen to often as the ringlands tend to stay in place they just crack like and the ringseal is lost...but if chunks come off or one of the rings bends it will scar the **** out of your cylinder walls.

You can safely run boost on your car with just a economical head swap...you could even go old school and just buy some 6.0 liter truck heads and drop your compression down to around 10:1..with no port work at all...it will only cost you the price of the heads but you will need upgraded dual valve springs.

If you decide to run boost on your 11:1 motor...I have a late model 2001+ LS1 for sale complete...and it has a GT2-3 cam (a little better then the 2002 LS6 cam (which is a great blower cam)...but you already have that cam so you should be in good shape with just a head change.

I also have some AFR dual valve springs for sale.

Good luck.

I agree 100% with you as this has been my personal experience as well as many of my friends and it can be viewed on this forum with a search...which will turn up all of the motors that have popped when people have chosen to go the high compression boost route. One could also visit the LS1tech site and do a search and find the same information....it is consistent.

On the flip side of things people choosing to run high boost on stock motors with higher compression...certainly have helped to keep vendors and tuners in business..some of them my friends.

69dodgecharger

I sent you a PM.

robert miller

Shinobi'sZ

Just curious if you looked at the above link first? While impressive it doesn't apply to the OPs topic. The question the OP posed was running boost on a high mileage, high compression (11:1) on a stock bottom end. I don't consider diamond pistons, total seal rings, and a Callies Dragonslayer crank anywhere close to a stock bottom end. Let us not forget the stronger block (case support) of the LS2 versus pre 2001 LS1 cases also.

Just for reference I have seen an LS6 D1 bend the stock rods when forged Diamond pistons were used. It was popular (and I think short lived) for some tuners to re-use the stock "powder" rods with forged pistons. The stock hyperuetetic pistons will not put up with any abuse when subjected to any sort of detonation under boost. They will pop faster then mentos dropped into diet coke (for you new guys) for you old guys Pop Rocks in regular Coke.


It really boils down to tune and ZERO tolerance for error...which if the OP chooses to run meth or high octane all the time or both....and a good tune..he should be able to do it. I kind of prefer just using 91 octane and throwing in some higher octane (mix) when I want to crank it up a bit.

100 octane is about $6-7 per gallon. At that pace (< 100 gallons) it wouldn't take that long to get up the $400 needed for some 6.0 liter heads off of Ebay.