Catback exhaust suggestions?

That's not a torque loss, you effectively reduced the height of your gear ratio with larger tires, therefore your engine has to work harder to accelerate. Increasing the exhaust on these trucks does reduce low end torque. These aren't high horsepower engines, and they come with 2 1/4" piping already, which is plenty for the amount of power these trucks make.

It's called exhaust velocity. Think of it like a water hose. You turn it on and it flows out nicely. But you put your thumb over it, and you get a quick, powerful stream. That's effectively what exhaust piping size does.

Intake will do almost nothing on these trucks either. Header does change the torque curve a bit.

 

Well, my catback is 2.25 to the muffler. Not seeing how the 2.5 out from there will change back pressure or torque. Intake is noise maker, washable non-oiled filter in a box breathing thru oem fender well opening & better looking when hood is open. The tooter IM spacer moves the peak torque down in rpms to a more useful range. The bigger heavier tires making the motor work harder is effectively the same thing as torque loss, call it what you will, end result is the same. That was on old truck, this one has a factory size tires. I have done nothing to try and add power. I have done things to up the driveability of what is there. Just like adding the short shifter doesn't improve the tranny strength or capability but it sure makes using what's there more efficient and fun. My need for speed doesn't involve a lifted aerodynamic brick. That has never been the point of mods on my truck. However, if I just remove the oem bug guard from the front of the hood.....

 

Increasing exhaust size It will change the torque curve from the low end to the high end on these trucks. Like I said, Toyota did a really good job in balancing the intake and exhaust to get decent low end torque and high end torque. The best mod for these trucks is a header for naturally aspirated. With a supercharger then you could really start to take advantage of other mods.

 

I think I'd opt for a 4.0 swap before doing SC on 2.7. I would love to have the 4.0/6 spd combo in my reg cab.....then do SC on the 4.0 instead if more was needed. Everything I've done to it has changed nothing as far as hp/torque/mpg but it definitely is more fun to drive than it came. Goal met.

For most part, any catback will be about same as doing any intake.....change of sound.

 

LC Engineering has a supercharger kit for the 2.7 that blows a 4.0 out of the water

 

I plan a supercharger, header, and cam kit for my 2.7

 

I'm old school and always enjoyed FlowMaster 2 chambers (as we used to call them). I have one sitting in a box at home (single in and single out). Just need to take the time to cut the stock muffler out and fit in the new one with clamps. No need to weld these things anymore IMHO when fitting it up with the stock pipe.

 

Until you SC the 4.0................