Well my friend and I had our cars dyno'd at Allspeed Auto Works today. Great shop in Peachtree City, Ga. Talked for a while with Tim, the owner, super cool guy. Highly recommend his place. Dynojet btw.

First graph is my car.

Pop charger, resonated test pipes, y pipe, and 5/16 plenum spacer.

Second graph is my best run and his best run. His mods include:

Pop charger, 5/16 plenum spacer and nismo exhaust.

So for everyone out there that thinks test pipes lose low end, or torque or whatever...eat your hearts out. Ha

 

VERY nice comparison

who ever said test pipes lose low end? I've never seen that...

now if only the other 99% of people who install mods had the same initiative to get them tested.

 

Test pipes will NOT lose any power in any rpm range.

The '04 clearly makes more power over the whole range compared to the '03. I bet your car sounds mean with the stock muffler and test pipes. Way to go!

 

Nice numbers, seem very much on par.

 

Ya Im happy with the way the car sounds and for less than the price of a nice exhaust I've probably doubled the gains of an exhaust alone.

pop charger..$110
test pipes...$300 (i got labree resonated, didnt skimp on these)
intense power y...145
motordyne 5/16 spacer...$230 I believe

Total of right at $800

 

I saw that shop in Peachtree City, but have never looked in there. I live close by in Griffin.
I put down numbers close to yours with roughly same mods.
Popcharger
TurboXS Non Resonated TP
Greddy Ti-C
Motordyne 5/16 Spacer

 

I've done comparative dyno tests of the stock cats Vs test pipes and yes, it is true that test pipes can lose TQ, but it's only down really low at about 1500-2200 RPM. Everywhere else the gains are really good.

Not too relavent to anything but low RPM cruising on the Fwy. ...but just in case someone wants to argue with you about it, technically, yes, its true.