procharger

[toppthat]

Im trying to decide if my ls7 can handle adding a procharger to my 120hp. over stock. I realise stock clutch wont be enough. But will i have some other problems? Im trying to get a non biased opinoin

 

[Hib Halverson]

It cannot.

Compression ratio is too high and you need forged pistons.

To successfully run a supercharger on an LS7 you need to pull the engine and change the pistons.

As for the clutch...you didn't say what the planned use of the car might be so I can't answer that question.

 

[toppthat]

Thanks. I am currently over half way to pro.and clutch. Lower end work talk was not stressed,as long as i kept boost around 4-4.5 lbs. Last round of mods included mast heads arp studs,and all intake and exhaust bolt ons. I want a faster z06(1/2 mi.)but will not sacrifice engine,for another 2-3000 for crank pistons ect. (Less sleep more work)

 

[Hib Halverson]

You're not going to get an additional 120-hp with 4-4.5lbs boost.

As I said...if you want a useful increase in performance and wish to get there with a boosted engine, you need to lower the compression ratio and go to forged pistons...especially, if by "1/2-mi" you mean half-mile drag racing or acceleration testing.

 

[6 Shooter]

Art had a procharger on one of his Vette's for quite sometime, my test drive in it was awesome...

 

[toppthat]

You're not going to get an additional 120-hp with 4-4.5lbs boost.

As I said...if you want a useful increase in performance and wish to get there with a boosted engine, you need to lower the compression ratio and go to forged pistons...especially, if by "1/2-mi" you mean half-mile drag racing or acceleration testing.

Thanks . Im gonna do it right. And im looking for a legal/local way for speed and i heard about events at airstrips,helmet only.

 

[TooFast]

Im trying to decide if my ls7 can handle adding a procharger to my 120hp. over stock. I realise stock clutch wont be enough. But will i have some other problems? Im trying to get a non biased opinoin

My apologies, but I am a little unclear about your post. Are you saying you currently have an LS7 with 120 additional HP (due to mods) and you want to add a supercharger? If so, I agree you cannot do that without internal (piston mods) in fact, as you exceed 750HP you will be stretching the limits of the aluminum block. However, if you have a stock LS7 and are questioning whether or not you can supercharge it without internal mods; then generally yes, there are countless examples of centrifugal supercharged "stock" LS7's without any internal changes, running successfully...you will end up somewhere in the 690-710 HP range with low boost; anything higher and you will run into trouble.

 

[Hib Halverson]

You said previously, you're thinking about running half-mile events held on airport courses.

If that's the intended use, you need the engine to be reliable for long periods of time at wide open throttle/high rpm at the 620-650-hp level.

At that power level and duty cycle, the engine simply will not be reliable with stock compression and cast pistons. The boost plus the high compression will have the engine in significant detonation. Even if you run high enough octane and retarded spark to keep the engine out of detonation, the heat you'll put in the combustion chambers will destroy a cast piston.

To be reliable and durable at that power level for sustained WOT, you have to change pistons.

I'll add that you're likely going to have to make some significant changes to the car's cooling as well to keep both the engine and the blower's charge air cooler cool.

 

[catbert]

I'm not as certain of disaster as HIB, but a half mile run may be at the edge of really pushing your luck. Twenty to twenty five seconds of WOT is do-able, but leaves no margin, and I wouldn't want to do it very often. Feel lucky?

As others have noted, a quarter mile blown Z seems to work pretty well, but you can't stress that big, little motor forever. Going with Hi's advice is certainly right for the long run.

 

[toppthat]

You said previously, you're thinking about running half-mile events held on airport courses.

If that's the intended use, you need the engine to be reliable for long periods of time at wide open throttle/high rpm at the 620-650-hp level.

At that power level and duty cycle, the engine simply will not be reliable with stock compression and cast pistons. The boost plus the high compression will have the engine in significant detonation. Even if you run high enough octane and retarded spark to keep the engine out of detonation, the heat you'll put in the combustion chambers will destroy a cast piston.

To be reliable and durable at that power level for sustained WOT, you have to change pistons.

I'll add that you're likely going to have to make some significant changes to the car's cooling as well to keep both the engine and the blower's charge air cooler cool.

I know your right about lower end. Any aftermarket ls7- F.I or not has calles crank and rods and mahle pistons. Im gonna follow their lead (mast)and go all the way.

 

[toppthat]

I'm not as certain of disaster as HIB, but a half mile run may be at the edge of really pushing your luck. Twenty to twenty five seconds of WOT is do-able, but leaves no margin, and I wouldn't want to do it very often. Feel lucky?

As others have noted, a quarter mile blown Z seems to work pretty well, but you can't stress that big, little motor forever. Going with Hi's advice is certainly right for the long run.

THANKS i needed some disaster talk.