cfr865

Anyone know if the new American Thunder axel back mufflers reduces h.p. , one person says it does the next one says it don't. I have them on order and suppose to have them installed Sat. Now I don't know what to do. Everyone has a different opinion on exhaust. Why would it loose h.p. Flowmaster said they tested them, and are for the 05 GT. If they decresed h.p. the word would be out and no one would buy them.

SilverR1_04

I'm planning on getting my Flowmasters this Monday, so let me know too! I don't know what model though, I'm assuming the same? Otherwise I'll just get the SLP Loudmouth afterall./

hawgman

The whole point of the American Thunder series was because the 40 series was reducing HP in the 05's. People that say they reduce HP are referring to the 40 series.

cfr865

I read in another thread you need to reset the computor after installing the new mufflers, has anyone else heard this?

Adrenal

I've had the Flowmaster kit for over a month now and can say there is very little difference as far as power. Most cat back or axle back systems are not going to have any significant increase in hp. I did not have to reflash the computer. I love the deep agressive sounds though.

hawgman

You can reset the computer, but you don't have to. With any intake or exhaust flow chanage, the computer needs to adjust itself. On intake, we reflash with the desired settings. On exhaust, the computer will do it. You can disconnect your battery cable for a few minutes ( some people say up to 30 minutes ) and that will reset your computer. OR, you just drive it and in 50 or so miles it will adjust itself.

1fast05GT

I installed my flows about a month ago. Obviously I would need a Dyno to find out if there was any decrease or increase of HP, but in my opinion I didn't notice any either way. I love the sound. I didn't reset the computer.