Removing the Cats..

stang&2Birds said:

I agree that I do like the sound of an x-pipe without cats on a 5.0. But, note what I say at the end.

Also many States/areas, they have noise pollution laws. And, the increased sound will not be legal. Also, it's a violation of Federal Law to remove pollution control equipment.

So, if someone doesn't have to pass smog, doesn't have to worry about noise laws, and doesn't drive the car much (we are talking about 20+ year old cars), and someone wants the sound of an exhaust without cats, then I see it as personal choice.

Still as I said, do NOT remove the cats to "gain HP". Unless it's a quarter mile track car, the LOSS of lower RPM torque and HP will NOT make the car faster or help it get better gas mileage.


FWIW: I have both. In fact, I have all "Four"!
1) BBK X-pipe with cats.
2) BBK X-pipe without cats.
3) BBK H-pipe with cats,
4) BBK H-pipe without cats.

BBK often has very good deals on returns. Just gotta keep checking. I've been checking for the past 10+ years. So, don't expect to find the deal you;re looking for in a short time.

For me, I like sound the BBK X-pipe with cats the best.

Click to expand...

While I agree with you with removing the stock catted H-pipe costing some Mustangs a little in the torque/horsepower department at many areas of the power band, this rule of thumb pertains more to later model Mustangs and the Fox body is most certainly an exception to the rule.

Adding an off road H/X-pipe to an otherwise stock 5.0L has show improvements across the board in countless dyno comparisons over the years. More so when combined with the rest of the exhaust system. While there may be the slightest penalty in the lower off idle regions of the power band, the gains made beyond that far outweigh the losses down low.

That being said....I would always recommend going with a high flow catted mid pipe as a replacement. Modern cats don't rob the horsepower that the older cats (like the ones our Fox bodies were originally adorned with) do. The horsepower and torque losses in many cases are negligible in all the but most extreme horsepower building situations.

My post earlier was based strictly on the audible tone a system like this provides, as the poster I quoted made remarks based strictly on sound quality. If I had the choice, I too would outfit the vehicle with a high flow catted mid pipe over an off road design as well. Partially because I can’t stand the smell of exhaust fumes in any of my drivers, but also catted mid-pipes do a better job of quelling the dreaded exhaust drone associated with aftermarket exhaust systems…which I hate even more than a stinky exhaust.