From reading the forums I gather if the exhaust is too free flowing you lose some low-end torque due to loss of back pressure.

If your exhaust has 4 cats, wouldn't they create most of your back pressure?
I wouldn't think factory cats would have too much free flow.

I want better sound and performance without losing any low end if possible.
Looking at true dual with magnaflow 14" DI/DO thru-X and 2.5 pipe.
Would 2.5 to the muffler then 2.25 to the tips help?

Any suggestions?

 

Loss of torque has more to do with loss of the velocity of the exhaust. In general, if the pipes are too big, you'll lose velocity, which increases backpressure. The only way to gain back the velocity is to increase the volume of exhaust (high rpms), which kinda defeats the point of low-end torque. Which is why not as many go with duals. 2 1/2" pipes might be too big for a dual, some of the experts here might have more info. I think that most folks have a 2 1/2" or 3" SI/DO for that reason.

Just my two cents...

 

i'm dynoing my van tomorrow then installing 2.25 true duals and x pipe next sat and will dyno again- we'll see any tq gains- i'll post pics and dyno charts-phil

 

Sweet! I'd like like to know how that goes.