I need to redo entire exhaust

[Pneub]

Originally Posted by YMAA

Your exhaust is plenty free-flowing. If you still can't get rid of the torque dip even with a supercharger AND uncatted headers, that's not a problem with restriction.

That's a tuning problem.

HKS Supercharger

Here's my dyno: http://i.imgur.com/mdz7Z3b.jpg

[FreshFRS]

Originally Posted by Pneub

The tune and install was done at Evasive Motorsports who have ample experience tuning. It's also been there a half dozen times and they don't seem to think its that loud. And it's not loud at it idle but on WOT you can hear this car a mile away.

even the canned tunes you get with any of the superchargers pretty much eliminate (most of) the dip, further optimizing that tune is only going to help. Evasives first tune looks like the dyno in post #37 http://www.ft86club.com/forums/showt...t+supercharger

Search any of the vendor threads for dynos; kraftwerks, jackson racing, vortech and even evasive's thread for the hks shows barely anything (~5lb/ft at most) for the torque dip with the canned tunes.

Wot with a header is going to be louder. even the stock catback gets pretty loud under WOT with a header/overpipe/front pipe.

[Pneub]

Originally Posted by FreshFRS

even the canned tunes you get with any of the superchargers pretty much eliminate (most of) the dip, further optimizing that tune is only going to help.

Search any of the vendor threads for dynos; kraftwerks, jackson racing, vortech and even evasive's thread for the hks shows barely anything (~5lb/ft at most) for the torque dip with the canned tunes.

Wot with a header is going to be louder. even the stock catback gets pretty loud under WOT with a header/overpipe/front pipe.

I have a hard time believing it's Evasive's fault considering how experienced with tuning they are. I wouldn't even know how to approach them and say "people on forum say you guys didn't do a good job tuning". Are there any other possible reasons?

[FreshFRS]

Originally Posted by Pneub

I have a hard time believing it's Evasive's fault considering how experienced with tuning they are. I wouldn't even know how to approach them and say "people on forum say you guys didn't do a good job tuning". Are there any other possible reasons?

please re-read the post you quoted, i edited it with a dyno on a bone stock car. look at the discrepancy in the torque lines between the two.

[Apoc]

Originally Posted by Pneub

I have a hard time believing it's Evasive's fault considering how experienced with tuning they are. I wouldn't even know how to approach them and say "people on forum say you guys didn't do a good job tuning". Are there any other possible reasons?

You should replace all your exhaust then it's obviously causing the noise and torque dip. No point in listening to few people on a forum when a reputable vendor has done your tuning.

[Pneub]

Originally Posted by FreshFRS

please re-read the post you quoted, i edited it with a dyno on a bone stock car. look at the discrepancy in the torque lines between the two.

Good point. I guess I'll bring it up with them. Something clearly seems way off in comparison

[InvalidJohnny5]

The quietest front pipe is the Milltek cat-delete. I run no cats in my car and it sounds like a stock STI.

[wparsons]

Originally Posted by Pneub

HKS Supercharger

Here's my dyno: http://i.imgur.com/mdz7Z3b.jpg

Compare your dyno:


To this dyno:



The other dyno makes a lot better torque curve, but not as much top end as yours. Are you running a different pulley? Anything else swapped out? It seems strange that the power curve is that different of a shape with the same supercharger kit.

[Pneub]

I'm running a different pulley. I have 11psi right now

[protpibe]

Like others have said, if you still have a torque dip with a supercharger and that exhaust setup, the problem is your tune.