Catback, X-pipe, Offroad Pipe, any true HP gain?

[04nccobra]

Looking to find out whether or not there is any true (dyno-proven) gains with the many aftermarket exhaust systems out there? Will a cat-back give you a gain, or do you need X or H pipes to realize it? So far none of the manufacturers will quote any dyno proven numbers.

I'm not concerned so much with sound as I am gain in power.

 

[moonltgold]

Based on my experiences with two cobras ('01 [na] and '04), three catbacks (Flows, Magnaflow, Bassani), and four midpipes (stock, Bassani, Magnaflow, custom built):

A good catback with nothing else on our car (04) is 20-25 rwhp. (By adding a good CAI this will go up add another 10-20 rwhp easily -- have to get more air in to get more out).
Aftermarket catted H or X -- not as much. Maybe 5 rwhp. Without cats maybe 5 rwhp more at peak/high rpm, like above 5,000, but will lose hp and torque below that.

 

[zacharyt1122]

Depends honestly. A good catback can produce a few extra horses, but you should consider sound as the most HP is going to come from a straight through muffler, which is going to be louder. I have glasspacks on my GT and it is retarded loud with the offroad x-pipe.

For most HP you will need headers back with an offroad h or x pipe, with long tubes and an x pipe producing the most HP in most cases. And honestly it is all going to depend on your mods currently. A stock car probably won't see a whole lot of gain with a stock eaton as opposed to say a Whipple with high boost.

Also, what are your plans with the car? If its a street car you may want a chambered cat back, depending on how much you can tolerate the loudness. Straight through designs are much louder, but again its preference, I like loud and can tolerate it more. Good luck.

 

[SVTRocket]

Based on my experiences with two cobras ('01 [na] and '04), three catbacks (Flows, Magnaflow, Bassani), and four midpipes (stock, Bassani, Magnaflow, custom built):

A good catback with nothing else on our car (04) is 20-25 rwhp. (By adding a good CAI this will go up add another 10-20 rwhp easily -- have to get more air in to get more out).
Aftermarket catted H or X -- not as much. Maybe 5 rwhp. Without cats maybe 5 rwhp more at peak/high rpm, like above 5,000, but will lose hp and torque below that.

This^

The actual research I've been able to find reflects the same.

 

[04nccobra]

Thanks folks decided to stay away from the X-pipe for now and just do a Dynomax catback kit, hoping to have it installed tomorrow.

 

[itzl0l]

Thanks folks decided to stay away from the X-pipe for now and just do a Dynomax catback kit, hoping to have it installed tomorrow.

very cool...keep us updated (make sure to make a good post) b/c i've been thinking about that catback as well....its fairly cheap and seems very nice...just doesnt seem to be alot of folks running it.

 

[04nccobra]

very cool...keep us updated (make sure to make a good post) b/c i've been thinking about that catback as well....its fairly cheap and seems very nice...just doesnt seem to be alot of folks running it.

Well got the Dynomax catback installed today, my installer (exhaust shop) says it was one of the best fitting cat-back systems he has ever put in, no problems at all.

The car is slightly louder at idle with a deep tone, standing in the rear you can hear it much better than in the car. In gear under throttle it has a nice growl to it, reminds me of the 5.0 mustang sounds, no high pitch or raspy tone at all. At boost and under hard throttle is where these mufflers shine, sounds like a muscle car, not an import. I am very happy with the kit, thinking of ordering a set for my Hemi Ram. :thumbsup:

As far as any power increase maybe a slight increase in the lowend power, haven't been into the upper rpms yet.

 

[jrgoffin]

I had the Dynomax cat-back kit in my previous Fox body and it sounded amazing (with an o/r X) - also had a very sweet muscle car rumble. If I get sick of my M55, I'll switch to the Dynomax kit without any question.