Axle-back, any gain?

[NorthwestGT]

I know you might be able to get a different sound, but are there any proven gains from any of the axle-backs? MM&FF ran a test a while back that didn't show anything much better than the OEM mufflers. But, just about every manufacturer claims gains of anywhere from 8-20 HP. Doesn't make sense.

 

[JTGrant]

you are no going to gain much from just axlebacks.

 

[discofan]

I know you might be able to get a different sound, but are there any proven gains from any of the axle-backs? MM&FF ran a test a while back that didn't show anything much better than the OEM mufflers. But, just about every manufacturer claims gains of anywhere from 8-20 HP. Doesn't make sense.

Dear NorthwestGT,

No significant gains but just more sound...

Stock exhaust comes pretty much opened up for the average stang driver...

Dave

 

[Stangnut]

The only advantage other than sound is in low end torque & hp. IIRC, at 2200 RPM, the gains were around 40hp & 28 ft-lbs. Which is EXACTLY where the 4.6L motors really need the gains. The numbers start to drop off pretty fast and by the time you're up to 4000 RPM there's no gains at all.

That's all according to the MM&FF test you refered to, but I'm pulling all those numbers from memory.

 

[boss377]

Not much HP, but transforms the sound from "rental car" to "kick-ass".

 

[NorthwestGT]

I think the gain is mostly in sound, but folks are still saying they dyno'ed such and such an axle-back and got 30 hp and 25 tq. Maybe I'm just skeptical, but I find it hard to believe.

 

[Stangnut]

Overall, you actually lose a little, but down low, where it's needed, you pick up a lot.

 

[StonePony]

The stock motor does not respond withmore HP from the reduced backpressure, it actually may lose a few.
I still can't figure out why so may people want to put on offroad H or X pipes. The cost does not justify them in my opinion.
I would love to see a dyno of how a stock motor responds to an X pipe or O/R H.