[Bullitt95]

I've decided to take a systems approach to modifying my Stang since I bought it so I started by removing all the rubbish that impedes performance (smog pump, EGR, air silencer, MAF screen). I also installed an MSD cap/rotor during a routine service.
Now I'm working on the intake system. I've done the C&L MAF kit and a larger TB and intake manifold spacer are next. Why not replace the intake manifold you may ask? I'm doing it later with the heads and cam.
With the intake system out of the way, I'll get a better response to gears so it'll be 3.73's for me.
After that, it'll be a full exhaust system from headers to tailpipe (MAC long tubes for torque, custom X-pipe, custom 2.5" cat-backs).
I'm not sure if I'll do underdrive pulleys. I'll be using the AC all the time in the summer so I don't want cooling or charging problems. Maybe I could do only the crank pulley?
By this stage I'll need to do other ancillary mods before what will be the final stage, the HCI (TFS Twisted wedge heads, TFS Stage 1 cam, Holley Systemax intake). Those mods will be the Tweecer RT, adjustable fuel pressure regulator, 24lb injectors, 190lph fuel pump, AODE Baumann shift kit and Baumannator tranny computer.

[acmsheva7]

hello i have a 1994 mustang gt convertible i just put a Mac O/R X-pipe with 2.25 flowmaster without tailpipes. Does this diameter size affect the performance??

[Bullitt95]

A dual 2.25" system should support up to 400hp (dual 2.5" supports up to 500hp) so unless you plan to do all the bolt-ons and supercharge later on, your pipe size won't be a restriction to performance.
If you really want to enhance your exhaust system, get rid of those terrible stock manifolds and replace them with a pair of 1-5/8" long tube headers.

[acmsheva7]

Originally Posted by Bullitt95

A dual 2.25" system should support up to 400hp (dual 2.5" supports up to 500hp) so unless you plan to do all the bolt-ons and supercharge later on, your pipe size won't be a restriction to performance.
If you really want to enhance your exhaust system, get rid of those terrible stock manifolds and replace them with a pair of 1-5/8" long tube headers.

if i get long tube headers can i modify my regular x-pipe so they can fit? or do i absolubty have to get a long tube header x-pipe??
or should i just go for shortie headers?

[Bullitt95]

Your regular mid-pipe is an H-pipe, not an X-pipe. You could have a custom H or X-pipe made to go behind the long tube headers.
Shorty headers are easier to install and you can retain your stock H-pipe and cats with them, but the performance gain with shorties is much less than with long tubes.
I'll be going for MAC 1-5/8" long tube headers, custom X-pipe, and custom 2.5" cat-backs when I have my exhaust replaced later this year.

[Mellemasfinest]

If you install a x pipe without cats will my engine computer have any problems?

[Bullitt95]

It shouldn't do. Many Stangers have installed offroad X-pipes without any issues. Your local smog inspector might not be impressed with a catless system though.

[Mellemasfinest]

lol, cool thanks for the help

Originally Posted by Bullitt95

It shouldn't do. Many Stangers have installed offroad X-pipes without any issues. Your local smog inspector might not be impressed with a catless system though.

[acmsheva7]

Originally Posted by Bullitt95

Your regular mid-pipe is an H-pipe, not an X-pipe. You could have a custom H or X-pipe made to go behind the long tube headers.
Shorty headers are easier to install and you can retain your stock H-pipe and cats with them, but the performance gain with shorties is much less than with long tubes.
I'll be going for MAC 1-5/8" long tube headers, custom X-pipe, and custom 2.5" cat-backs when I have my exhaust replaced later this year.

no, i already have a mac off-road x-pipe with stock headers my question was if i could have a muffler shop modify my x-pipe so it can fit long tube headers??

[Bullitt95]

I don't see why not.

[whitepony1995]

Dude go with gears 3.73 trust me you will be happy

[Bullitt95]

Originally Posted by whitepony1995

Dude go with gears 3.73 trust me you will be happy

x2
I'm very happy with mine. The 3.73 r&p dramatically improved acceleration in each gear even if it made little difference to the 1/4 mile ET/trap speed.

[acmsheva7]

do you need any extra parts when you install gears??? or can you just buy a complete gears kit?

[Bullitt95]

I also bought The Yukon master bearing kit for the 8.8 from Late Model Restoration and had that installed at the same time as the r&p.

[cobraman7594]

Of all the mods I've done, the 3.55 gears were the biggest noticealbe improvement! It actualy knocked a full second of my times! Had mine installed over the winter, cost alot more than I bargained for. All of the bearings in the rear end, including the axle bearings were pitted and worn! It was worth the money though.