I've been running the Borla ProXS muffler (relocated under the cab) for over a year now. Sounds great and it really lets me hear what the engine is doing when I step on the throttle. My only complaint now, and I'm not sure if it's the muffler's fault or not, is that at low RPMs I don't seem to have the power/torque I want. Once I get up over the 3k mark, I'm pretty good. But from 1k to 3k it feels/sounds flat.

I'm wondering if I need more back pressure at the lower RPMs.

The Borla is a free-flow exhaust that I did plenty of research on before I chose it. Unfortunately there were no dyno comparisons run on JKs, so I found a great muffler comparison done on Ford Mustangs. Of all the mufflers they tested, the Borla was the best overall muffler for hp/torque gains without high sound volume. Of course, they are rating the gains at higher RPMs. I'm looking for gains at lower RPMs.

If more back pressure is needed at low RPMs, I'm wondering if something like the DynoMax VT would be a good choice. With that internal valve it has, I would think it would produce more back pressure until it actually opened up at higher RPMs to become a free-flow exhaust.

What are your thoughts?

 

Your used to it and it feels slow. Look into superchips

 

Already did (see signature).

I've done most of the basic performance mods available. I have increased power, don't get me wrong. I just feel like it could be better, should be better, at lower RPMs.

 

I see in your future, a new gear set on the horizone.

 

Gears will come when I pull the trigger on 35s. Until then, I'm just trying to fine-tune the setup I have.

Are we saying my lack of back pressure is not the cause of my lackluster low RPM power? Even the exhaust sounds kinda bogged down until I get out of the 2 to 3k range.

 

Your cats do more for back pressure than the mufflers on these modern vehicles.

 

I noticed in your Sig that you have already increased your tire size quite a bit over OE. So you have already made a change in your gear-set so to speak. Just not a good change. I'm thinking that this is what is responsible for that fealing of loss of power.

 

Yeah, I'm sure that's a lot of it. Just looking for any little way to get some back. Was hoping the back pressure was at least one, inexpensive way. Gears aren't an option right now.

 

I am a little interested as well as I have found a similar case with my RPM band.

I run with no muffler.