It feels like i'm dragging a house...

Since i did all my engine stuff (see signature), it hasn't felt quite like i would expect... this may also be because i had my new tires put on right before the mods. but i only went from 28.7 (Wrangler HP's) to 30.1 (Dueler A/T Revo). It just feels like the engine is struggling too much. I remember reading about people thinking that 2.5" exhaust has too little back-pressure to produce the correct torque... is this feasable? I have not been able to find the threads. Do i just need to re-gear? I'm planning on re-gearing to 4.56's, but just have to wait for the time and $$ to do so. Any thoughts are appreciated. --Chad--

There's a good write-up about exhaust on gojeeps's site:

http://go.jeep-xj.info/HowtoExhuast.htm

By going to larger tires you force the engine to run well below the torque curve for the engine (until you re-gear). By going to the 2-1/2" exhaust you killed any low-end torque you had.

Yes ... you NEED to re-gear. Your gas mileage is going to suck until you do, too.

30's shouldn't feel much different than stock, nor should you see a serious decrease in gas mileage. This isn't tires/gears...it's something else.

Nay

Agreed. I went 3 years on 31 10.50s before regearing. Once I did, it felt like I had a new engine. It was a LOT easier to keep up to freeway speed(btw: 75mph in Colorado).

well, i'll admit i'm a bit heavy on the skinny pedal... It's not THAT bad, but i feel after putting near $3000 into the jeep that it should perform better than this. I know i will gain a lot from the re-gear, but would like to resolve this problem before hand.

Nay said:

30's shouldn't feel much different than stock, nor should you see a serious decrease in gas mileage. This isn't tires/gears...it's something else.

Nay

Click to expand...

30s typically measure around 29.4" ... a tire measuring 30.1 inches as noted in the initial post is either a metric tire or a small-ish 31x10.50

Just looked at Audiophile's sig. All those fawncy intake and exhaust mods are aimed at flowing more air at higher RPM. None of them improve low-end torque or street driveability. You can't have it both ways.

I plan on stroking the engine, or supercharging it.. that's why i wanted it all free flowing. But for now, should i have my exhaust cut behind the muffler and have a 2" put on from there back?