Crackerballer

I know that alot of people are searching for more HP on their forced induction cars, and don't wanna boost over a certain PSI, so I think a thread should be started about how you all have pulled more HP out of diff parts without up-ing the boost. Like throttle bodies, intake manifolds, cams, timing, valve train, etc. We all know TUNING is the biggest one, but I want to hear what parts, name brands, style, etc where effective, i.e size throttle body, what intake mani, cams, timing. Just thought it would be a good reference for everyone.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crackerballer &raquo;</TD></TR><TR><TD CLASS="quote">I know that alot of people are searching for more HP on their forced induction cars, and don't wanna boost over a certain PSI </TD></TR></TABLE>

That's because they don't know what they are talking about. PSI isn't a stress on the engine... it's the interplay of power, quality of tune, and rpms on the bottom end. What PSI you hit that power on is divorced from the reality of the situation.

When you go running off your compressor map, or most popular compressor maps, without getting the full cfm that your compressor is capable of, that is when you reach into the bag of tricks to make more power at a lower PSI. We are talking about a power level you can't put to the ground in a streetcar, so it seems pretty pointless.

TurboJesse

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">

That's because they don't know what they are talking about. PSI isn't a stress on the engine... it's the interplay of power, quality of tune, and rpms on the bottom end. What PSI you hit that power on is divorced from the reality of the situation.

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...but the cool thing to do is make the most hp with the least amount of boost

boostn420

What you guys are talking about is efficiency, and thats good. But another thing that tends to come with it is reliability.

Crackerballer

Yea I know its not about peak Hp, and what you can put down, but what I am saying is, the average FI person knows a set PSI their car can handle, for whatever reason. I was just trying to see what some parts were that showed good improvements in top end, or low end, or mid range, whatever. ANd ye,a how reliable has it been, etc...

stackz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crackerballer &raquo;</TD></TR><TR><TD CLASS="quote">I know that alot of people are searching for more HP on their forced induction cars, and don't wanna boost over a certain PSI, so I think a thread should be started about how you all have pulled more HP out of diff parts without up-ing the boost. Like throttle bodies, intake manifolds, cams, timing, valve train, etc. We all know TUNING is the biggest one, but I want to hear what parts, name brands, style, etc where effective, i.e size throttle body, what intake mani, cams, timing. Just thought it would be a good reference for everyone. </TD></TR></TABLE>

another one to add to that list would be upgrading the turbocharger itself to a larger unit = more volume per psi so even at the same psi rating you'd be getting more air into the engine.

0xenocron

Cracker,

Reread J. Davis's post...

Its NOT about PSI...its about POWER (HP), RPMS, & the tune.

I can make 350 @ 7psi or I can make 250 @ 7 psi...there's gonna be more "stress" at 350 HP...

OR...

I can make 350 @ 7 psi or I can make 350 at 14 psi, same amount of "stress" on the engine basically.

Crackerballer

Ok so let me see if I am gettin this right. If you have more Hp, on less boost, I.e the 350 on 7 psi, and u get that from bolt ons, tuning, etc, it will put mroe stress on ure engine than if the car was running 14psi with a conservative tune, and less bolt ons?

The reason I ask this question is because I will be turboing my GSR this summer, and want 320 very usable WHP, and I wanted to do it on about 9 psi. I figured that 9 psi should get me close to 300 hp, and the rest I could squeeze out with a nice manifold and throttle body, come cams and head work.

I was gonna use an SC32, hopeing it would quickly spool.

SO maybe I will be better getting bolt ons, a conservative tune, and runnin bout 11PSI?

I just want a car that has full boost aroun 6k and is very streetable, pulls hard in the mids, and con slay a z06 from a stop or roll.

0xenocron

The numbers I used were examples...just so you know.

If you want a streetable, "usable" setup, use Torque when looking at things instead of horsepower. HP is a max rating, its a marketing thing that people & companies use. HP directly comes from whatever torque you acheive.

Remember that FI is different than NA. You cant just turbo your ride, have it tuned, and then slowly add more "bolt-ons" like you would NA.

Every bolt-on will throw off your tune, and you will more than likely need a tweak done to your tune as free-er flowing things like manifolds, exhaust, Cams, whatever increase your engine's VE (volumetric efficiency) and will make the tune you paid for run leaner than intended.

And full boost around 6k is ludacris!!! try to shoot for lower than that or it wouldnt be classified as "streetable" or "usable" IMO

Crackerballer

Ok, yea i guess full boost by 4500 would be better, and yea i see what ure saying about the tuning issue, so I guess I should turbo it, then see what happens, then add things in chunk, i.e manifold, TB, and a fuel rail all at once, tune, then maybe like cams, port and polish, and valves, then tune. I got it. Thanks guys

Joseph Davis

How hard you blow in the intake (PSI) doesn't mean anything. Stop paying any and all attention to the boost pressure as a yardstick of performance. The power exerted on the crank and rods; the cylinder pressures, spikes in pressure if you are near/at detonation, exerted on the sylinder walls; and rpms you spin as force on the rod increases as a square of the rpm are what you worry about. When you max out a component, it is due to power level or tune and not PSI.

People have some wierd idea in their head that the boost figure is impressive and what you need to pay attention to, when it's whp and your engine's ability to deal with that whp that is impressive. Pick a power level, figure out what is needed to build a bottom end that can reliably handle it, and select your turbo to suit power level and engine displacement and power band. Once you get your desired power output, you monitor boost figures as a safety measure to make sure something isn't, or doesn't get, completely fucked underhood.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crackerballer &raquo;</TD></TR><TR><TD CLASS="quote">I just want a car that has full boost aroun 6k and is very streetable, pulls hard in the mids, and con slay a z06 from a stop or roll.</TD></TR></TABLE>

Hahahhaa. Right. After you finish shitting money all over your engine, make sure you get to race the Z06 from a roll as well as from a stop.

Crackerballer

Ok, so what are you saying about beating a z06? It can't be that hard, they are quick cars, but i mean, i should be atleast be able to hang, maybe not slay.

TurboJesse

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crackerballer &raquo;</TD></TR><TR><TD CLASS="quote">Ok, so what are you saying about beating a z06? It can't be that hard, they are quick cars, but i mean, i should be atleast be able to hang, maybe not slay.</TD></TR></TABLE>

It will be hard from the dig, especially on normal street tires, i can take them from a roll, but its over from a dig..