Good point, I completely forgot about that part.. I knew I was missing something

 

I had the same idea....

"Oh I could just turn it here and.... wait." Lol.

 

I don't know if this will help but its something to think about. About 15 year ago I built a short box Chevy with a 383 stroke and ran full exhaust with header dumps. Never had a problem while running thru the exhaust but one day I opened the dumps. I wasn't even running that hard but I sank 3 valves into the heads. I was pissed the motor only had 5000 miles on it. I asked some of the old rodders why the hell did this happened. They said because of the hi lift can about the valve springs I had. They said I needed the back pressure.
Its just food for thought. I know when I opened the headers it sounded awesome but it was a dog.

 

x2 on balancing back pressure with intake volume.. In general air, fuel, spark and compression all need relative increases to improve HP/TQ... But, either way, no back pressure is no good..

 

I just can't see how anyone can stand having larger then 31 inch tires..... Even with a 4.10s and a ram air intake it still feels so slow, as in 10 second 0-60s/17 second 1/4 miles/fearing for life merging onto highway. My old XJ would pin you in the back of your seat off the line.... Do 31s and 4wd t case really slow it down that much? Feels the exact same as a 4.0 4wd WJ I test drove. I raced my friends 5 speed lifted Cherokee on 33s with a 4.5 inch lift(3.55 axles) and im slower! My old XJ was much faster then his Cherokee. I am barely faster then a Honda civic automatic.... This is like pure hell lol I have a lead foot and people don't know when I floor it :|

 

I could barely beat a stock 1992 Nissan Pathfinder!!! Yes the 150 ish hp 3800 lb boxy one...

 

ok, here's a few suggestions. Get a full exhaust, ie header, muffler, hi-flow cat. Throttle body spacer, it helps out a pretty good bit. Seal off your intake to where its actually breathing in cool air (the cooler air, the easier it will breathe). Go to your local jy and pull a electric fan off of a ford taurus, get rid of the clutch fan. Clutch fan causes drag on the motor. You could also get a 160 deg thermostat. It won't help with the hp or tq, but it will allow the engine to run cooler. Also, when was the last time you changed plugs and wires as well as cap and rotor button? You can upgrade the ignition as well. All of that will allow the engine to get the optimal spark to ignite the fuel, which in turn will allow for more mpg, as well as more power. If you want to really get some power out of it, look at doing a stroker. Your mpg will suck, but you will have plenty of power. There are a ton of things you can do to help get better performance. When I went with my 31"s, my power dropped considerably. But I did all these things and the only other thing I have done is re-gear. That gave me a ton of pull off the line.

 

Sure your truck is working right? My jeep isnt fast but itll get out if its own way. I beak my buddies Pacific and my brothers Xterra with ease. I also have a 500hp mustang the jeep doesnt feel overly slow. And a 5 speed shouldnt be that much faster.

 

It's a jeep. If wanted something fast then would build a muscle car or something. Also hope you raced on the track and not on the street with your friend

 

That's what I was thinking too, the carfax says it had 182k miles in 2008 and 198k in 2009 and my odo says 172k?

 

Raced in Mexico, just because someone considers a car that does 10 second 0-60 slow does not mean they have something wrong with them and require a muscle car. I consider 10's turtle slow, 9's slow, 8 seconds acceptable, 7's fairly brisk, 6's kind of quick, 5's fast, etc. My old XJ was acceptable.... I might be trading my XJ for an Acura Integra GSR, I think I rushed in buying my current XJ and $65 fillup every 5 days takes a toll.... That's $400 a month, same car payment as a new Wrangler. I went 200 miles on a tank, my old XJ went 250 miles. Just thinking about it, I still might keep it, it's a heart vs head dilemma...

 

Dumped at rear axle will drone inside I didn't like it to much for me jmo. I've changed injectors, tb, tune up, specter cai, flowmaster 40. Its gotten me back to stock I feel, I'm on 31s an even helped with gas.

 

Alright thanks for feedback. The 31s slow me down more then I think...

 

The drone will be less with more lift though right?

 

I lost to 80s Chevy reg cab, 4.6 F150 extended cab, dead even with an auto integra LS, and beat a 3.7 crew can ram.... I would have beat all those with my old XJ, in fact I did. Even with newly installed jet stage two, CAI, Magnaflow and high flow cat.... these 31s have got to go, you know it's bad when a Civic knockoff with an auto trans is faster then you almost. Maybe my 99 had more off the line grunt due to it's high flow intake ?