Ofcourse we all know that N/A requires High Compression and Turbo applications call for relatively low compression ratios - my question is - how do we balance having both? Done a few searches, but not much has come up....

In the future - i definately want to run my S2StageII cams with a turbo setup...

Any opinions...?

 

You'll have to get a good tuner who can tune it so it doesn't detonate.

 

So what would be he ideal compression ratio whn using both?
Is there a good tuner in the Indianapolis area? I only know one guy, but he doesn't have a dyno in his shop.

 

It all depends on how much power you want to make... If your one of those guys who wants to be able to make 400whp on pump gas then it's good for you to go low on compression around 8:1-9:1. but if you dont really care about making max power on pump gas and will be fine with 250-350 on pump gas and 400+on race gas then you should go 9:1-10:1. Me personally i don't really care about how much i can make on pump gas so i went with 10:1.

 

Yeah - here in Indy, we get 93octane....I'm just trying to make 300whp thats all - don't want to really do too much with a prelude - love them, but i'd rather get an Sti or something....

 

those big cams are just gonna leak out all your boost.....if you want to keep them, and run a turbo to make 300 whp, you will have to find a good *** tuner, and you will want 10:1 or lower.....so just get a set of usdm h22 pistons if you dont already have them....

why would you buy an sti anyways....for the money you could get a regular wrx and make it way faster and better than an sti....

 

I guess thats true - What do you mean the cams will leak out all the boost? i'm confused on that statement - can you explain

 

or you could get an evo 8 w/ 10k miles on it for like 22k and be faster than a wrx w/ bolt ons... not to mention much better handling

 

i will just give you a basic theory here to explain myself, im in a rambling mood:

your skunk2 stage 2 cams are made for an all motor engine, they have bigger lobes for more lift and duration, letting more air/fuel into the cylinder per combustion and different lobe spacing for more overlap....

all motor engines depend upon efficiency to make good power, they need to make the most powerful explosion per stroke, so the more air/fuel, the more powerful the explosion, which is why your s2stg2 cams are designed the way they are....

another component of all motor efficiency is not only gettting a lot of fresh air/fuel into the cylinder, it is to get the old, already burnt mixture out.....cam lobe overlap is used to take care of this: as the exhaust valve is open to let out all of the exhaust gases, the intake valve opens before the piston reaches tdc on its exhaust stroke(that is what overlap is, when both (all 4) valves are open at once), and the air that rushes in the intake valve helps to force the air out of the exhaust port.....in turn, the vacuum created by the exhaust flowing out of the port helps to pull in more fresh mixture from the intake port.....

that is how all motor cams are designed, big lobes and big overlap to make good efficiency....

now, for turbo motors, they dont need as much, but still need to some extent, the help that big lift and duration give, because the air is forced in, the cam lobes can be relatively small and plenty air/fuel will still get in......

now, as this air is rushing in, it helps to force the exhaust gas out, so overlap is no longer needed, and actually ends up having a negative effect.....if there is overlap on the cam, as the boosted air rushes in, it just rushes right out the exhaust port, with no overlap it cant leak away, hence my statement about leaking boost.....

this is why turbo cams are designed with some fairly sized lobes for lift and duration, but no overlap at all, or very very little....

so, basically what im saying is: choose a way, either all motor or turbo, those cams will kill your turbo setup, and you will have to run a lot more boost than normal to hit your whp mark.....

phew....that was a lot, i hope it all makes sense, let me know if you have any more questions.....

 

[QUOTE=flip1199]It all depends on how much power you want to make... If your one of those guys who wants to be able to make 400whp on pump gas then it's good for you to go low on compression around 8:1-9:1. but if you dont really care about making max power on pump gas and will be fine with 250-350 on pump gas and 400+on race gas then you should go 9:1-10:1. Me personally i don't really care about how much i can make on pump gas so i went with 10:1.[/QUOTE

maybe thats why you ran 14.6...... lol

 

the stock cams are good for a turbo application. i've seen people make 600whp on stock h22 cams. i wouldn't waste your money on buying cams for a turbo h22 motor, but if you're n/a, then you'd probably want to get some. i'm more of a boost man myself......but as far as the balance between both n/a and boost - you're kinda comparing apples and donkeypoop. you can either build for n/a, or boost, but you can't really build for both. guys who build turbo motors with high compression pistons can make a shitload of power- Steve at Oaks Racing for ex. has 10.5:1 compression on a boosted motor, making 788whp.....but this is of course on race gas and not for everyday driven vehicles like you've probably got. for the reliability you need in everday driving with boost there is a simple equation:

sleeved block + 9:1 compression + stock cams + moderate-to-high boost + pump gas = awesome reliable power.....and awesome torque too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boost3d22 &raquo;</TD></TR><TR><TD CLASS="quote">[QUOTE=flip1199]It all depends on how much power you want to make... If your one of those guys who wants to be able to make 400whp on pump gas then it's good for you to go low on compression around 8:1-9:1. but if you dont really care about making max power on pump gas and will be fine with 250-350 on pump gas and 400+on race gas then you should go 9:1-10:1. Me personally i don't really care about how much i can make on pump gas so i went with 10:1.

maybe thats why you ran 14.6...... lol</TD></TR></TABLE>

that 14.6 was on stock internal with no traction till top of 3rd thank you...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flip1199 &raquo;</TD></TR><TR><TD CLASS="quote">that 14.6 was on stock internal with no traction till top of 3rd thank you....</TD></TR></TABLE>


hence a 2.4 60ft time with a 102 trap speed.