Gentleman,
What is the max compression ratio I can have with a procharger supercharger. I currently have LPE heads 63cc 11 to 1 with a 228/588/114 cam. I woutd like to install a procharger and keep the heads and cam. Would using a thicker head gasket alone work? Is anyone running a procharger with 11to1 compression.
v/r
Steve Yav

 

I run up to 10lbs of boost on my stock LS6 motor 10:5 to 1 compression and 11:to 1 is too high but you could probably get away with 5lbs of boost with a good tune.

That beings said, For $1,300 you can buy brand new Patriot LQ9 CNC BLower Heads 72cc, and that will knock you compression down close to 10 to 1 and you will be GOOD TO GO!!

 

ATI Procharger's web site has a chart on it that shows boost on the Y-axis and static compression ratio on the x-axis (for pump gas). You can use this to see what is feasible.

--Sean

 

A change in heads to LQ9 truck heads or use thicker head gaskets to bring the compression down a bit and you should be ok. There is a guy up this way who has a p1sc on a 10-1 compression and he's been fine running about 9 lbs of boost. Drives his car to Florida every year and no problems for over 2 years.

 

One that's a bandaid, two a thicker head gasket has a negligible impact on compression reduction, and three thick head gasket are less than optimal for forced induction applications.

Why not just sell off or trade your heads for some that have the chambers opened up? Heads are pretty cheap these days.

Forgot to mention that you can run a supercharger at 11.0:1 CR, just make sure you run good fuel.

Mark

 

And spray meth!

 

Thanks gentlelman for all the info. Looks like a head change or run a low boost 5 psi. Like tuners everyone has their favoriate. Currently what supercharger gives you the the best bang for the $$$.
v/r
THEYAV

 

The 8 Rib ECS Novi kit would get my vote.

Mark

 

Mine as well. If you're in the market for a blower, there's your answer.

 

This may be of some help in your decision process. I pulled off my A&A P1SC kit(red lines) and installed a TTi TT stage 3(blue lines), both on a stock LS1 '99 C5. When we started to dyno tune we did 2 pulls and quit to adjust the wastegates and now I have to go back for a final tweek. Here's a dyno chart where Dan overlayed the best chart of both kits. We ended up with roughly the same HP but way more torque with the turbo. You can see how the power comes on much quicker with the TT.

 

"Here's a dyno chart where Dan overlayed the best chart of both kits. We ended up with roughly the same HP but way more torque with the turbo. You can see how the power comes on much quicker with the TT."




EXACTLY, and that is why the centrifugal supercharger is more practical since it gets you out of the hole for a great 60 ft time (instead of going up in smoke) and makes for much better 1/4 times that way!!!

 

That must be why the fastest C5's have turbos.

Mark

 

Yes, and that is why the quickest (as distinguished from fastest) have centrifugal superchargers

 

Jimmy,

I have a question for you as well as others here. When I look at some of the big hp TT dyno charts here I see the same ramp up of TQ at roughly the same RPM as my graph. Somewhere between 3000 and 3500 rpm the TQ is at or close to 450+ and I repeatedly here bashing of these TT systems because the power comes on too quick. From what I see, the only difference between mine and theirs is the fact that their power continues up to 600, 700 and in some cases 800hp. Yet those systems are just perfect in the application of power. Seems I'm missing something. The one thing I did not like with the P1sc is the fact I had to scream the engine to get any real power from it. Now I get more in the power in the range I typically drive in(2500-4500). I'm not a 1/4 mile guy, just too much abuse on the drivetrain IMO.

Also, I noticed something I can do with the TT is moderate the boost. I can give enough gas to hold a lower boost until I get the rpm up. The P1SC could not do that. It was an all or nothing system. The turbo is load based and the SC is rpm/vac based.

My guess is that anyone with more than 450hp/tq will roast the tires down low.

Almost forgot something. The hole shot, I found was slower with the P1SC because the blower caused more drag than it produced hp down low. I drive an A4 and I can't spool the motor up to 3000 to launch. So for me the SC was a dog off the line until I hit 3500rpm and then it was a game of catch-up.

 

I'm sorry, but I just don't get this post. When giving performance opinions it's much better to make them factually based (ie. ET/MPH)
rather than subjective opinions.
I also don't understand how anybody who has driven a centrifigal supercharger can say "it's all or nothing". Most of the time my boost meter shows "0", but when I get on it you can see the boost number increase. (C5 LS1 D1SC)
And "it's a dog off the line", well I don't know what gears you were running, but with my 4L60E/3:42 I am usually leading the first 60' race even against faster cars.
My car is also a daily driver with 595rwhp and don't have any problems burning up my tires, because when I go to the strip I change to appropriate tires.
As to "spooling the motor up" that's what high stall converters are for.

 

It sounds like you get it without knowing it.

What's subjective about a Dyno graph? Putting that aside, just as you said mostly you see 0 boost and then gas it and boost comes up. If you let up slightly on the gas the boost dies quickly. "All or nothing"

I did say I'm not big into the 1/4 mile thing and so much is based on driver experience/error anyway. Hardly objective IMO

My car is a daily driver and mostly stock with 2.73 diff, stock stall. I honestly don't like the ride of a high stall car. The drivability is not to my liking. Which is why it takes time to "spool" up the engine to get 4#s of boost at 4000 rpm and 9#s at 6000rpm. Now I get full boost at 3000 rpm.

Lastly, you confirmed my point again. Any car above 450 will roast tires in a slow roll.

But this misses the point. I hear critics of the TTi TT because it gives too much boost down low. I see no difference between mine and other Hi HP TT setups except for the fact their power reaches astronomical proportions that would otherwise scare the heck out me. It's great for racing but anything above 450-500 hp on the street is silly and almost pathological IMO. But it take these guys doing big HP setups that helps us in the low FI stratta.

 

I'm talking about stock cube LS6 C5's with turbos that whoop the **** out of big cube blower cars.

Mark

 

Yep they sure do, but then they have to go back and help sweep all the varoius drivetrain and motor parts off the track. and the blower guys are pissed off because they have to wait to run again

 

All in good fun gentleman, all in good fun!!

 

Naturally. We all know that superchargers are easier on the driveline. How couldn't they be - they make less power.

Mark