Originally Posted by Fast_Freddy (Post 997938)

So are you running the Q300?

Originally Posted by Gardus@Supersprint (Post 999542)

You could change the headers and overpipe and keep the stock front pipe with the secondary cat and the rest of the OEM system.
In terms of power increase I have no sure values but my guess is around +7-10 hp of peak power at the crank, probably more than 10 at 6000 rpm.
You'll need to sort out the O2 sensor issue with a microcat/emulator/cheater, with a ECU tune or extending the wire and plugging the sensor after the secondary cat instead of between primary and secondary (you must weld a bung!)

An even better idea is to replace the front pipe with the secondary cat with a sport cat, along with the headers. You'll get the same increase of a full system, low emissions if you go for a good cat and a nice sound increase.
Don't go for a fully decat setup with the stock centre and rear exhaust as it'll be VERY metallic. We've tested this solution and while the car runs fine (no time for dyno testing) the sound is not very good. We're thinking to make a resonated front pipe for this purpose (full decat front section with stock or aftermarket catback)

Originally Posted by Gardus@Supersprint (Post 1001620)

Hi Simmons. Did you dyno the car before and after those mods (without the tune or with the same tune both times)?
I'm skeptical about the advantage of a unequal lenght header kit, aside from the advantage of the removal of the primary cat.

Originally Posted by Simmons (Post 999865)

This is what I had last week, JDL UEL Header, Perrin over pipe, Perrin front pipe with hfc, and stock cat-back.

It was very quiet, maybe a little louder than stock.

Originally Posted by Fast_Freddy (Post 1129524)

Okay, I received my Tsudo catted front pipe from Jon Motoring and it is a true objet d'art. Much prettier TIG welds than any other front pipe I've seen yet and 304SS polished to perfection. Perfect fitment, 200 metallic substrate cat and 1/2" thick, perfectly flat flanges. Jon Motoring even included a 304 SS L-shaped O2 spacer much like one sold by Weapon-R for $60. All this for $170 with free shipping? WOOT!!!

Originally Posted by Aaron_blatherwick (Post 1130386)

You really should get some sound clips up, that is exactly the set up I am wanting to do also, I have decided to do the muffer last if at all. The header and hi flow cat front pipe will be first. I want the real nice sound and the hp gain in the torque dip from the uel header, but I think with cat back it might be too loud for what I'm looking for. I don't want people to hear me coming from a mile away as I drive spirited on their lake road. I'm really wanting to try and get the rev works header but the price of borla is hard to pass up, as long as they hold up on their end for warranty issues.