I've been getting conflicting ideas whether or not test pipes help or hurt in a SC application. What have you guys experienced? If it makes a difference, I run a Procharger 7psi pulley and a Borla TD exhaust. Now if this has been covered, just point me in the right direction. Thanks.

 

its been covered....more flow...more power....less flow...less power

 

free flowing is much better for FI than NA

 

I have test pipes and am making very good power. I am planning to get some hi-flow cats, just to cut back on the slight rasp from the pipes, though.

 

Booger,
I'm sure your right, hence me saying, if this has been covered already, please point me in the right direction. I see plenty of post regarding turbo's, but not for my particular application. And yes, I do realize my car falls under the "FI" application, but turbo's and SC are not the same.

 

A motor is a air pump . The faster you can get rid of the air , the faster more can be pumped in by a SC . Example....I had test pipes , Stillen dual exhaust...made 7.5psi and 350whp . I got tired of the loud exhaust and added Crawford cats . I gain 1.5psi [9psi] and lost power and had to retune to get back the same 350whp . Because of the exhaust restriction of the Crawford cats I couldnt make more power with more boost . The air couldnt get exspelled fast enough to take advantage of the extra boost

 

Booger,

So if I dropped the Crawford H/F cats and put on a full exhaust and resonated test pipes my boost would drop and my hp/tq would go up? (with a retune)

If that's the case, could I then add the 2.87 pulley (and get back to the same boost levels) and be 'as safe' due to being at the same boost level or would that not factor into the equation because the hp/tq would be increased?

 

Boost pressure and back pressure are all rerlative need to keep in mind. If you increase back pressure and boost increases you have gained nothing here in fact you are hurting your self with the added restriction. The Vortech and the ATI are set in there ways they will only flow so many CFM of air not gonna change unless you change something.

IF you change your exaust and boost dropps doesn't really matter as CFM will remain the same. But your engine has to work less to expel spent gasses so you will increase power with proper tune. If you restrict flow you will need more agressive tune to make same power.

Adding the 2.87 pulley will increse CFM so boost pressure will increase more air more power

 

What John said...LOL...He can explain it better and knows waaaaay more than me . PMed you John

 

drop me a email will send you pics of 3" tubing

 

So, if the test pipes are added, will there be a drop in power until a re-tune can be done? Or will the power be the same, but running a lower boost pressure because of a less back pressure?

 

I had test pipes on my car for a little while.. no re-tune... I lost a little low end torque driving in and around town but in the higher rpm ranges, the car was definately faster.. The difference was noticible..

I have since gotten rid of my test pipes in favor of high flow cats.. only because my exhaust was LOUD AS H3LL and i couldn't take it anymore LOLOLOL

--mike

 

Leemik, always good to hear from you.

 

As Leemik stated lost bottom gained top. This is true, In most insances even N/A but not with turbo. Since we are not dealing with a turbo were more flow from exaust increases reponsivness form compressor the supercharger cares not how fast or slow air is moved it will only move so much according to it ratio. The thing I would be most concerned about is your A/F ratio when you do the swap!!! Things to remeber the richer less torque and kind sluggish, leaner more torque and crisper throttle responce. Just the way these tune out!!

 

I'm not sure about a Pro Charger, but I am testing a Stillen Super Charger on my car right now, and when we put a set of straight pipes on the car I lost power. After talking to the engineer at Stillen I was informed that this particular kit needs that back pressure or you loose some of your boost in the exhaust. Again I'm no engineer but I saw the Dyno numbers and that's what I was told. I'm not sure how it should effect your Pro Charger, But there's only one way to find out

 

Well, after getting some different responses on the subject from here as well, I went ahead an e-mailed Procharger for there input. I'm sure I will get a response back sometime.................this month.

 

I currently have resonated test pipes, but am probably going to be switching over to HFC's due to the smell...not so much the rasp though. How much power will I lose with a stock Vortech? Will I need a retune after the switch?

 

...

 

I have test pipes, and am making good boost and wrhp

 

I have test pipes and I'll agree, it is loud as hell. However, I am making decent power and it is noticable in the high rpm range used when drag racing.