Exhaust gurus help me out

mjh78

Member
Oct 12, 2007
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ok basically on an 00GT you're looking at 3 major sections of the exhaust..headers, midpipe (xpipe), and catback. Is this correct? I don't want longtubes for certain reasons and from what I hear shorttubes really aren't even worth the time and effort. If I go with a catback alone and maybe down the road upgrade the TB and plenum, is that going to make a pretty decent gain for me as far as a little more kick and better throttle response? How much more of a difference would an aftermarket x-pipe make in addition to these? I'm looking at the Bassani BX catback priced at around $489.
 
Don't bother with a Plenum and Throttle body unless your planning to go FI because you won't see much gains from it.

And you are correct that shorty headers do not give much gains, people see good gains with long tubes but it is alot of work to get them on and you said you don't want them anyways.

I would go ahead and do a Midpipe and cat-back at the same time if I was you. Might as well get it all knocked out at once while your already under the car. Bassani CB's sound awesome so you won't be dissappointed if you go that route. Have fun picking and installing the exhaust.
 
The mid pipe is where you’re going to pick up your most gains. Most people would say go with an off road mid pipe (No cats) but I say get a catted mid so you don't lose some low end torque. Also a TB and plenum will probably net you about 10 hp more and much betther throttle response. I would say with TB, plenum, mid pipe and catback you could gain around 20hp. Then get a Xcal II or III and you will be up probably over 30+ hp. I would also suggest steeda U/D pulleys (5+ hp gain). Every little thing will add up in the long run as you can see. If I was going to do it over again I would skip on the exterior mods like getting my hood scoop and wing painted plus getting the window louvers and honey comb tail panel (all adding up to probably $500 or more). The only exterior mods that are a must are the mach 1 grill delete and the chin spoiler.
 
thanks for the info. so the stock x-pipe is much more restrictive (versus the OEM) than the catback is (versus the OEM)? If so, heck if an aftermarket catback is more or less just a big improvement in sound and maybe a little bit in power, I might consider just keeping what i've got from the cat back and replacing the xpipe. I love the sound of my exhaust right now. from what i can tell the previous owner had welded on some aftermarket mufflers, but as far as I know the rest of the piping was left as-is. any problem with an aftermarket x-pipe and leaving the rest as-is?
 
thanks for the info. so the stock x-pipe is much more restrictive (versus the OEM) than the catback is (versus the OEM)? If so, heck if an aftermarket catback is more or less just a big improvement in sound and maybe a little bit in power, I might consider just keeping what i've got from the cat back and replacing the xpipe. I love the sound of my exhaust right now. from what i can tell the previous owner had welded on some aftermarket mufflers, but as far as I know the rest of the piping was left as-is. any problem with an aftermarket x-pipe and leaving the rest as-is?

The 99-04 Mustangs come with H pipes and 2 cats per side. As said above you will feel a big difference if you get 3.73 or 4.10 gears
 
Have thought about gears too. Let me say this, maybe my tires are crap..they are like Khumo Korean tires. I have 285's in the rear. tread looks fine on them, but even with the stock gears...even if I just roll out of first and gradually put it to the floor, after about 4k there is quite a bit of tirespin. however, maybe this is normal even for a stock GT? definitely have given the 3.73 gears a thought. not sure if 4.10 is overkill or not. I don't want to spin the tires in 1st everytime I give the throttle even a little bit of juice.
 
Have thought about gears too. Let me say this, maybe my tires are crap..they are like Khumo Korean tires. I have 285's in the rear. tread looks fine on them, but even with the stock gears...even if I just roll out of first and gradually put it to the floor, after about 4k there is quite a bit of tirespin. however, maybe this is normal even for a stock GT? definitely have given the 3.73 gears a thought. not sure if 4.10 is overkill or not. I don't want to spin the tires in 1st everytime I give the throttle even a little bit of juice.

It might be your tires, I have an automatic but when I all I had was 4.10s it would chirp them on the 1-2 shift and sometimes the 2-3 shift. These were on BALD stock tires with like no tread on them at all. LOL