streetxj
NAXJA Forum User
- Location
- Pembroke Pines, FL
I just wanted to discuss my experience with a few exhaust configurations that I've used on my 96' jeep cherokee sport for those who are thinking of getting certain things done to their exhaust.
First of all, my 96' jeep XJ is a 2 wheel drive 2-door model, hence the name "streetxj" with some modifications. The mods are 2003 jeep 4.0 intake manifold with some light porting done to the injector bosses, 62mm ported throttle body, bosch 703 fuel injectors, 180 thermostat, Intake Air Temperature sensor relocated to the stock intake box lid (I live in south Florida), hood vents, Gibson GP400S header, Crushed down pipe beneath the header collector was replaced with a section of smooth pipe, 2.5 inch high flow cat and 2.25 inch catback.
Setup 1: Thunderbolt 425250 cat, Aero turbine muffler AT2525, 2.25 inch dynomax tail pipe. I've noticed that my exhaust was a bit smellier with this smaller high flow cat and on occasion during early morning cold starts it will have a brief even misfire, then it evens out. During hot 80 + degree (Fahrenheit) humid weather, the jeep will have a noticeable lack of power when I floored the truck from a dead stop (I was not speeding and I was testing it out on an empty road) and an overall uneven power curve (like torque management on steroids). During 70 degree weather or below, the jeep felt like a completely different truck. It had no lag and had much better acceleration and an even amount of torque throughout the entire rpm band. The engine didn't feel like it was castrated.
Setup 2: Same as setup 1, but the exhaust was much louder due to something that I would not mention in this or any other jeep forum. The result was very similar to the first setup, but more noise.
Setup 3: I grew out of the loud exhaust phase of my life and wanted to make it quieter. The jeep now has the Thunderbolt 445250 (Heavy-Load) cat which is 2 inches longer than the original smaller Thunderbolt cat, a 2.25 inch Jones Maxflow (similar to Magnaflow) muffler and the 2.25 inch Dynomax tailpipe. WOW, that is all I can say. This setup sounds like the factory stock exhaust setup with a bit more growl in regards to interior noise levels. The idle feels smoother and the engine climbs through the rpm range more smoothly as well. There is actually more power through out the entire rpm range without any noticeable flat spots in the power band (jeep feels more zippy) and I don't need to press down the accelerator as much as before and this result was experienced in 80 degree weather. The exhaust smells like a clean OEM exhaust too.
Basically, for those wanting to install a more economic-friendly high flow cat on an OBD-II jeep 4.0, I highly recommend the the Heavy Load version of the Thunderbolt cat and for those wanting to get a mod done that is not allowed to be discussed, I would REALLY not recommend it. I hope this information was helpful. :read:
First of all, my 96' jeep XJ is a 2 wheel drive 2-door model, hence the name "streetxj" with some modifications. The mods are 2003 jeep 4.0 intake manifold with some light porting done to the injector bosses, 62mm ported throttle body, bosch 703 fuel injectors, 180 thermostat, Intake Air Temperature sensor relocated to the stock intake box lid (I live in south Florida), hood vents, Gibson GP400S header, Crushed down pipe beneath the header collector was replaced with a section of smooth pipe, 2.5 inch high flow cat and 2.25 inch catback.
Setup 1: Thunderbolt 425250 cat, Aero turbine muffler AT2525, 2.25 inch dynomax tail pipe. I've noticed that my exhaust was a bit smellier with this smaller high flow cat and on occasion during early morning cold starts it will have a brief even misfire, then it evens out. During hot 80 + degree (Fahrenheit) humid weather, the jeep will have a noticeable lack of power when I floored the truck from a dead stop (I was not speeding and I was testing it out on an empty road) and an overall uneven power curve (like torque management on steroids). During 70 degree weather or below, the jeep felt like a completely different truck. It had no lag and had much better acceleration and an even amount of torque throughout the entire rpm band. The engine didn't feel like it was castrated.
Setup 2: Same as setup 1, but the exhaust was much louder due to something that I would not mention in this or any other jeep forum. The result was very similar to the first setup, but more noise.
Setup 3: I grew out of the loud exhaust phase of my life and wanted to make it quieter. The jeep now has the Thunderbolt 445250 (Heavy-Load) cat which is 2 inches longer than the original smaller Thunderbolt cat, a 2.25 inch Jones Maxflow (similar to Magnaflow) muffler and the 2.25 inch Dynomax tailpipe. WOW, that is all I can say. This setup sounds like the factory stock exhaust setup with a bit more growl in regards to interior noise levels. The idle feels smoother and the engine climbs through the rpm range more smoothly as well. There is actually more power through out the entire rpm range without any noticeable flat spots in the power band (jeep feels more zippy) and I don't need to press down the accelerator as much as before and this result was experienced in 80 degree weather. The exhaust smells like a clean OEM exhaust too.
Basically, for those wanting to install a more economic-friendly high flow cat on an OBD-II jeep 4.0, I highly recommend the the Heavy Load version of the Thunderbolt cat and for those wanting to get a mod done that is not allowed to be discussed, I would REALLY not recommend it. I hope this information was helpful. :read:
