I just installed this on my 08. It had been tuned a week ago and dynoed. I posted those results earlier and now I have new results WITH ONLY THE CATBACK INSTALLED so we have dyno results that reflect ONLY this mod! I'll post the charts tonight when I get home.
Basically I got 5-10 LbFT increase between 3500 and 4500RPM..and 5LbFt increase above 5000RPM. HP increase was a maximum (10HP) around 4000 RPM and PEAK HP was up about 4 HP. Charts to follow..stay tuned.

Dyno showing Gemini Catback added ( BLUE) vs previous dyno which included TUNE and Nismo Intake RED.
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This is previous dyno showing TUNE vs Stock (had Nismo Intakes).

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NOTE!
THIS PARTICULAR DYNO IS TO THE HUBS (DYNAPACK) AND READS ABOUT 25 HP HIGHER THAN DYNOJET, OR 8% HIGHER

 

not bad now you need to get headers and HFC's on that bish lol...

 

Yeah..but I'm an 'ol fart and don't like a loud exhaust

 

Its REALLY not loud at all...its very conservative..

I think it could also be cause i have HFC's and not test pipes...test pipes have a tendency to get the exhaust tone kind of raspy

 

Charts just posted.

 

were??

 

Did ya mean *WHERE* are the charts posted?
If so look at the original post again.

 

i feel better about my gemini.

 

UGHH! my bad dude...websense blocks images at my work sometimes so i dont c anything haha...i guess ill have to look at it at home, all i see is the test in the OP.

 

I wanted to nail down any gains to be had with this on an HR motor and now we know...you really get a nice bump in certain areas. Peak HP is very misleading. I think DE cars with a more restrictive Y pipe may get even better gains, since the HR Y pipe is pretty efficient.

 

^ most definitely. i have no complaints with the exhaust other than it's too quiet for me when I want it loud. However, i love how civil it is at highway speeds of up to 80, or under normal driving.

I'l throw on some test pipes later on and get a tune to really open her up.