GreenYJ
Registered User
- Location
- Marysville, CA
I have a 4-banger YJ (and proud of it)...I just need a little more. I have heard of people installing a 4.0 throttle body on the 2.5l. Has any one ever done this and do they notice an improvement.
Throttle Body engine upgrade
- Thread starter GreenYJ
- Start date
tweakeyjeep
Soccer Mom
- Location
- Sandy
GreenYJ said:
I have heard of it done on a 4.0, but not on a 2.5... On the 4.0 it usually helps out probably like 2-3 hp... Not sure on torque, but I am planning on getting one.
I don't know if the 2.5 has it, but on my 4.0 I opened up my air box tube and inside is a funnel type air restrictor. I pulled that out (I had to mangle mine with needle nose pliars) But I think it gave me maybe 10 hp... Can't notice a huge difference on flat roads, but the big difference is on big hills, I could leave it in gear not worry about downshifting.
yes, I ahve heard of it being done ut never done it myself...but basically what you are doing is allowing more air in but you need to let mroe air out too inorder to get full advantage of it...I tried several things on my 2.5L and IMO most weren't worth anything...
BTW, the 2.5L do have the resrictors in the air tube also...
BTW, the 2.5L do have the resrictors in the air tube also...
GreenYJ
Registered User
- Location
- Marysville, CA
supergper said:
Yeah I took that peice of plastic out, added a K&N filter, added a poweraid spacer. So if I were to put a 4.0 throttle body on and then buy a new header and pipes then that should increase the airflow out, right. well which brand header is best and which is bigger than stock. "if mess with one thing you mess with it all."
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tweakeyjeep
Soccer Mom
- Location
- Sandy
GreenYJ said:
Sorry... I should read your posts more clearly... I thought you were putting on a 4.0 Throttle body spacer onto a 2.5 throttle body... My bad!
For the headers, I'm not sure about that, I personally don't want headers because they give you torque in the higher RPM range, rather an exhaust manifold will give you torque in the lower RPM range.
I just added on 2.5" pipe and a magnaflow muffler all the way out, kept the stock manifold and piping to the catalytic convertor and with that alone (plus k&n and modified tube in airbox) I think I got about 10-15 horsepower.
I wouldn't do the entire exhaust system unless you put on a new intake system, like the K&N FIPK Kit. Just my $.02
grinch
inner city redneck
- Location
- Salt Lake City
Your right not orrignal but still looks good. I have yet to see a mettle fender flare that looks good thoagh.... well maybe on a fj 40 or somthing like that but thats only a maybe......
tweakeyjeep said:Sorry... I should read your posts more clearly... I thought you were putting on a 4.0 Throttle body spacer onto a 2.5 throttle body... My bad!
For the headers, I'm not sure about that, I personally don't want headers because they give you torque in the higher RPM range, rather an exhaust manifold will give you torque in the lower RPM range.
I just added on 2.5" pipe and a magnaflow muffler all the way out, kept the stock manifold and piping to the catalytic convertor and with that alone (plus k&n and modified tube in airbox) I think I got about 10-15 horsepower.
I wouldn't do the entire exhaust system unless you put on a new intake system, like the K&N FIPK Kit. Just my $.02
hahaha, actually the TB spacer is the same PN for the 4.0 as it is for the 2.5
...you are correct in you assumption about needing new exhaust, but its not really just a matter of size as an aftermarket design is usually more free flowing than the factory one...I cant give you any reccomendations for specific brands cause I have never tried any of them...tweakeyjeep
Soccer Mom
- Location
- Sandy
supergper said:hahaha, actually the TB spacer is the same PN for the 4.0 as it is for the 2.5
Well, one thing I noticed about the Flowmaster Design and the Magnaflow design (on the inside of the muffler I mean) is:
I am not skilled enough to draw a diagram, but the Magnaflow is a straight free flowing muffler, it is almost straight though... It goes from right side inlet diagonally to the left side exit... Straight on the inside, no restrictions.
Flowmaster is the same way, but has some restrictions to get a better resonating sound... Kinda looks like this.
\\\\\\\\\\\\\\\\\\\\\ Entrance Side on right, exit on left
/////////////////////
I saw both mufflers cut open.
Just my $.02