Posted this in response to someone's question about exhaust systems, but thought I'd post it here too so that it's easy to find.

The graph below is the Stillen full cat-back on my '06 G35 6MT vs the OE cat-back. Test was done on U2Ndyno.com's Dynapack, which seems to read a bit lower than the DynoJets we use in town but produces very repeatable results so we like it for its accuracy and reliability.



Maximum gains were 13 lb-ft of torque and 12 horsepower at 4400rpm, with peak gains of 8.5whp at 6300rpm and 8wtq at 4900rpm. The exhaust note is slightly deeper and more aggressive than stock but it's a mild upgrade in terms of sound...it just enhances that unmistakably VQ growl a bit and there’s zero resonance or other sound intrusion while cruising on the highway. I'm very very happy with this system, plus it fits perfectly. The welds are not JDM tight yO, they are MIG welds done by hand in the good old US of A, but it's full stainless and all the parts that show (mufflers and tips) have been polished to a mirror shine, so it looks just as good on the car as any other system.

Here's a few pics of the system on my G...

 

Hey Dave, the picture links aren't showing up. Can you check them? Thanks. Any sound clips?

SC

 

I have some sound clips of the injen exhaust if your looking for them. Keep in mind I also have an Injen Cold Air Intake, Kinetix HFC, and UR Pullies.

But feel free to check it out. Www.youtube.com/ackilles85

 

Thanks SC, fixed the pics I hope

 

My bad, I had assumed this was the Injen kit, not the stillen lol. I didnt mean to spam ya, I was wondering why it had the 2 canisters

 

Nice video clip, Alpha Ice. Definitely has more induction and exhaust growl than the Stillen stuff. Nice sporty sound, though for me, I wanted something very close to stock with regards to sound level since I drive my G a good 100 miles 5/days a week and the cops around here are always looking to write tickets for noise. I wouldn't mind if the Stillen exhaust was a tiny bit more aggressive sounding, but I'm guessing that when we add headers and high-flow cats we'll pick up a bit more growl.

As for why the Stillen has two mufflers, that's because it's a true dual exhaust. This means it weighs a bit more than a single canister setup, but it also flows better and muffles sound better as a result. Personally, I love the fact that this exhaust is so quiet yet provides excellent power gains throughout the rev range. I'm all about flying under the radar with my street cars and this exhaust is a perfect fit for that kind of build IMO.

When I want to get rowdy and loud, I bust out the race car

 

Great gains on the overall powercurve in that graph. Thanks for the contributions Dave.

PS. Can you post more pics of your car? I'm loving those GT-F's!

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Will post up some glamor shots for you tomorrow, Henry. The car is still pretty much stock on the outside, other than the Volks, clear corners, and shaved rear emblems.

The GT-F are rolling works of art...pictures don't really do them justice. There's just so much detail and precision in the way these wheels are built and assembled. Car is still stock ride height, but have KW coilovers going on soon. Size on the GT-F's is 19x9.5 +17 front and 19x10.5 +22 rear. I think once the car is lowered and the alignment dialed in the overall look of the car will be much improved.

Going to pick up a set of 18x10's for track day use, since most r-compound tires don't go bigger than 18's. Thinking Advan RS's in Gold, though CE28's or TE37's in Mag Blue would be pretty baller too

 

Here's some glam shots of the G with the Volks for you, Henry!

 

nice