Cats or no Cats
 

I would like anyone's opinion on the cats matter. I have a 2000 GT and I just removed the cats. The car sounds GREAT!!! But was told that I may lose in the low end. I feel like I did lose some. Is this true or is just a myth.

My next step is to install and offroad X-pipe and a set of long tube...should I put high flows on or not.

Thanks for any reply,
GerryGT

cats restrick the exaust. I have bbk full length headers, off road h-pipe, and Mac mufflers and tails. sounds great and good power.

Once again I was talking to tireburner about this and he reminded me it adds horses and for the minimal torque loss that and the sound makes up for it :D

I would dump the cats ( keep the catted pipe for the sniffer test if you have it in your area)

i have high flow cats...i dont like them.

You know the cats are not THAT restrictive! You know the 03 Cobra puts down about 370 H.P. to the wheels stock! With cats! If they were such a restriction they could never have made that kind of power. Now on the Cobra removing them frees up a lot of power, BUT you have a lot of power to begin with. In my experience having cats or no cats is only about a 5-7 H.P difference on a 300 rwhp car. The 96 Mustang is an exception as it has 6, yes 6 cats from the factory. a bit of overkill and Ford went back to the 4 cat H-pipe in 97. Just look at how fast a 99 or up GT is with JUST the addition of a 6-9 psi Supercharger! Look at the Steeda Q cars, the Roush cars, Look at the Lightning! lots of power thru the stock cats! Maybe they are not as bad as made out to be! Now if we are talking about ANYTHING older than 97 then you have a very valid point about the cats. The older cars ect just did not have the advantage of technology that is available today when it comes to exhaust systems and cats in particular.

Technick: Every bit of horsepower counts. That's why bolt ons are so popular, they're fairly cheap and when a couple are performed, you can really see it in your et's and by the seat of pants. I have an offroad h-pipe on my 5.0 and my friend has one on his 99 and it sounds mean. I'd definately go with the offroad version for any application. ~Brian

Brian you are right every bit of H.P. counts, BUT, I seriously doubt that you would feel or even see a E.T. improvement with just the 5-7 H.P. difference. You will HEAR the difference, but in reality you would not see a bit of difference at the track. 5-7 H.P. just does not show up at the track in a 3,400 lb car. Now if the cats are removed in addition to other mods at the same time then the story is different. In a lighter car it is possible to MAYBE see a difference, like a 2,500 lb car it might show up. On average in a late model Mustang (94-up) it takes at least a 15 H.P. difference to show even a .010 drop in E.T. Thats 1 hundredth of a sec.! To drop a tenth you are looking at something even more dramatic. And of course the faster the car the bigger the improvement HAS to be to show up. So I guess if you have a 20 sec car 5-7 H.P. would show an improvement. But on a stock 13.8 sec Mustang you are really splitting hairs to even get that one hundredth of a sec. improvement. It will SOUND like 1/2 a sec improvement, but that is all. I am not bashing the idea of removing the cats even though it is against Federal Law to do so. It all adds up in the long run and you have to start someplace, I am just pointing out that on average it just does not make much improvement if that is all you ever do. If done in conjunction with other things, then yes it can be a more significant change.