mb7

what are the average power/performance gains from an x-pipe?


thanks

Diabolical!

None. X/H pipes are purely a sound mod. There are those that will swear otherwise, but any gains that people get go hand in hand with a tune, and the tune would have found that power with or without an aftermarket mid-pipe. The stock exhaust flows remarkably well on S197s until you get into the extremely high HP range.

mb7

So your saying even after deleting the cat's there is still no power gain?

Diabolical!

The exhaust flows great from the factory. Shorties, off road mid pipes and mufflers should all be considered sound mods. Long tubes can net you gains, but even then only on modified cars. If you're looking for power, look elsewhere. If you're looking for sound, lose the cats.

Nuke

An O/R X will gain some RWHP due to the loss of the cats but a stand-alone X won't gain enough to distinguish from the normal variance between back-to-back dyno pulls. Also, the X will add some raspiness that isn't appealing to some.

MustangFirstCar

Yeah, you are really not going to see any significant gains from that alone. Its all about what sound you want.

Recon111

The reason a V8s have to have a X or H pipe is because of the extra exhaust pulse created when there are two cylinders firing in succession on the same bank, there has to be a place to relieve the extra pressure.
As far as HP gain goes, There will be a gain if there is no X or H pipe, but if there is one already there's no gain. Removing restriction in exhaust flow will always gain hp, no cats, no mufflers, open headers etc.
Removing restriction will also lean out the air/fuel ratio.

Wil

Wouldn't you lose torque if you removed all the exhaust flow restriction??

NJBLK07GT

Removing the cats for a high rpm situations will help with horsepower but for average driving taking the cats out will hurt your low end torque and performance. You need some back-pressure for that low end of the power band.

Recon111

Wil
Big difference between "all" restrictions and removing cats or open up headers or removing mufflers. If you took the exhaust manifolds off, that would remove all restrictions and cause a whole host of problems.
Removing Mufflers or cats or opening headers will reduce restrictions and anyone will increase HP and Torque. You still have to have SOME back pressure to function correctly. Tuning exhaust is an art. To much of anything is not good.