Now that was a good Monday Update! :)

You're both right. In most cases, we recommend a 3" diameter exhaust to be used with TT applications. Most turbocharged vehicles from sports cars to diesel trucks benefit from larger diameter exhaust, mainly because turbochargers flow a much greater volume of exhaust gases than a naturally aspirated engine. So under full boost, the turbocharger needs flow as much exhaust gas as possible to continue to spool as quickly and efficiently. However, some customers prefer the 2.5" look and sound to the 3" True Dual, and they may sacrifice small amount of top end power, but the smaller diameter exhaust usually produces a bit more low end torque than a 3" exhaust car.

Short answer, both 2.5" and 3" work perfectly fine with turbocharged cars. :tup:


You had a CA too?? That's awesome! I had a CA in my old S13 Fastback, and I loved that engine! My "baby RB", as I called it.

http://i43.photobucket.com/albums/e3...g?t=1264517797

^Ahh, memories. The turbo feel, high revving, signature CA "tilt"...

Sometimes I really miss that old car.

Fire her up yet? :excited:

Needed : Dyno Chart

TUESDAY!!! Lou drive his car?!?

I agree. I looked at your dyno and you lose so much low end tq and power, I really want to see how the 2.5 will effect these numbers down low.

The tq curve isn't to good. In my opinion since the cats are 3in might as well go 3in all the way back

I am excited to see if the lower power band will change

I decided to go bigger on the turbos. I feared that with the smaller turbos and bigger exhaust you would lose the low end power. That and my power goals would not be met with the lil turbos :D hehe GT30's or bigger in my book lol

How long until your kit arrives?

Better question, how long after the kit arrives until it is done? :tup:

Majority of the kit is here I just uploaded pics from my phone to my computer and will be posting a thread tonight :D now I am waiting on the supporting mods and backorder items like the K&N Filters, fuel system and what not. Once I get those parts in I will have a tenative date tto drop the car off at Forged and it should be no longer than 4 weeks until she breaths again! :excited:

Good Luck Bullitt!

Thanks Lou! Same to you! I am enjoying your build hehe we are def gonna have to meet up after our builds!

Yes, 3" is ideal for a TT but "the bigger the better" is not true. 3" would be maximum for that setup.

EDIT: just saw Jon's response...I'm redundant redundant