Making Power on a 1-3/4 x 3 " header & 2.5" Catback....

[broke7]

Just wanted to throw this out there with my experience. There seems to be alot of questions on exhaust size from LT's to Catbacks thrown around. Recently got my new combo together, no dyno #'s yet. Its fairly simple.

Ran [email protected] last weekend, on a fairly conservative tuneup, and shakedown passes. Car weighs around 3650.... 6 speed, IRS.

Teksid 9:1
Stock Heads
Comp 3's
KB 2.8H @ 23psi custom inlet like the mammoth/behemouth.


Exhaust setup....
ARH 1-3/4 x 3"
ARH 3" Xpipe, and 2.5" Ball connector at end
Borla Stinger



I guess from my personal experience, you dont need HUGE 1-7/8th header, & full 3" to make big power, and run solid #'s. I plan on running again this weekend with a little more boost, #'s should improve.

 

[Bdubbs]

I have the same exact headers and x pipe going on my car as we speak. I'm running 2 1/2" bassani catback. I'm not expecting big hp improvements though, as I'm not making huge hp already. It seems headers fair better on higher hp cars.

 

[stangfreak]

I agree. Mustang magic was building two cobras. Both with built engines cams 2.8 kb etc etc. one car had custom exhaust 3 inch and huge headers. Venomous johns car had off the shelf Mac 1 5/8 long tubes mac pro chamber and magnaflow catback 2.5 inches. Both cars made the same power.

 

[Woody6799]

From what I read 1 5/8 is the way to go on the Terminator motor up until the 725+ area. Considering I am not going that high I grabbed a 1 5/8 kooks set up and I am sticking 2.5 back. Why go bigger if it doesn't help your end goal?

 

[Cabbage]

I did 1 3/4 x 3 ARH to bassani 2.5" this spring. With a 2.93/4lb combo on my stock eaton/fuel system my car layed down 485/529 on 94 octane but up here I believe it's 10% ethanol not sure how good the fuel is but it's the most octane at the pumps available The sound alone is worth it. I love it. The car sounds like it has 700hp. Lol. Can't wait till the tvs and new fuel system this winter.

 

[Stage 4.6]

I have the same exact headers and x pipe going on my car as we speak. I'm running 2 1/2" bassani catback. I'm not expecting big hp improvements though, as I'm not making huge hp already. It seems headers fair better on higher hp cars.

Bdubbs, did you get your car dynoed after the header install? curious to what kind of power improvements the 1 3/4 header w/3in X gave you?

 

[04ScSaleen325]

Am i loosibg powet with my 1 7/8 kooks ( previous owner installed them) is it worth the hassle going down a size

 

[broke7]

No, I dont think so. I have always been told the power is in the collector design, and muffler choice. I would touch a thing