What exhaust are you guys running? Ive always heard that these superchargers love backpressure.... but wouldnt getting any aftermarket exhaust reduce backpressure resulting in no power gain?

Right now Im looking at either FI or Stillen exhaust. I love the way HKS looks but I want to hear how it sounds in person.

Do these superchargers perform best with stock exhaust?

What gains/losses would I be expecting?

 

i put on a borla before i even went with the stillen,so i really cant give any positive or negative impressions.

 

I'm in the same boat as ^ I had my Greddy SP2 rear section and Topspeed headers on before the S/C install. Sorry...

 

Yeah I also had the Greddy Sp2 rear before the install but I doubt that it would make any difference. Hows the supercharger with those headers by the way?

 

Seems fine? Haven't had a chance to dyno yet. Haven't had a chance to install my gauges yet, either, to measure boost...

 

Ohh hehe... When I installed my gauges it saved me from potential problems..... I was overboosting cause I had the wrong pulley....which caused me to go on the lean side From what I read maybe you lose boost from the headers?

 

Anything that is on the exhaust side will increase flow and decrease back pressure. You will loose boost but the flow will be more. On my 03 roots blower cobra I lost 2 psi with a cat back and picked up 30rwhp.

 

Believe me...that is not the case with these VQ motors. ...... I wish.

 

There is no real gain in adding a better flowing exhaust in conjunction with a (Stillen) roots style SC, as far as power goes. If you are after the sound of a new exhaust, then by all means, go for it if you wanna spend the money. It won't really hurt power but you won't gain any either. When you open up the exhaust even more with headers, you really start to loose too much back pressure and, in turn boost, then power loss. These style (roots / twin screw) SC really like back pressure unlike a centrifugal unit that WILL benefit from better breathing.
Keep in mind, this Stillen (Eaton M62) SC will loose its efficiency after 7.5 to about 9 psi. After that if you try to make more boost with it (by way of a custom higher boost pulley) you will experience a great deal of heat, cavitation, and power loss.
IMO, stay with the stage 2,3, or maybe even 4,but don't expect to see anything that will give you any real power gains except maybe a methanol drip system (about +10whp), or cams (about +17whp). And remember there is no full proof, "safe" FI kit out there, I have seen this Stillen SC claim just as many motors lately as anything else on these motors. Its all in the tuning....whatever you get make it tuneable and have it tuned.

 

So if I go with a stillen or procharger the I wont pick up any gains from a cat back or cat delete?

 

You will pick up some but not much from exhaust side mods. Too little back pressure with the Stillen and you may end up hurting the low end and not feel much on the high end of the power band.

 

Only with the Stillen is this the case. With a Procharger or a Vortech (centrifigal SC) You do stand to benefit from exhaust mods.

 

That's inline with my common sense reasoning. Who cares about boost #'s, if your hp/tq #'s increase? That's what you're ultimately after, right?

 

One more time.....
With this Stillen (Eaton M62) roots style SC, you will not gain any HP or TQ. by opening up your exhaust on these VQ35 motors. You might slightly change the TQ. curve, but you will not stand to gain anything, and you stand a good chance of loosing power / torque. Trust me.....

But if anyone wants to do what I have already extensively have tried to do (extract any and every ounce of power out of this blower) than knock yourself out!

 

Guys he is right. I tried high flow cats on my stage 4 and lost a couple hp.