The exhaust is not under-designed.

The only time there would be more intake air is at wide open throttle and high RPM, like redline.

I have installed oversized TBs on 4.0s with stock exhaust. I have installed free flowing exhausts on XJs with 52mm throttle bodies. I have installed 60mm TBs on XJs with free flowing exhaust.

Each mod individually mad some improvement. Make sense?

 

Yup I understand what you are saying. I guess each one can make a difference. I would just think to maximize either exhaust or intake, you would have to do the other.

 

But you don't have to.

They're complimentary, not necessary. And neither of them is a HUGE improvement anyway...............

 

Thank you guys,

Yes I adjusted the TPS but I haven check for slack on it..
Maybe the is the issue.
I just dropped the jeep for a replacement exahist pipe replacement. Have to be done anyways due to bad welding issue. Let's see if this helps.
The air intake that I using is a aftermarket cone type, I have been thinking maybe a specter cowl swap... Hear that is loud but I don't care much about that .

What about injectors or fuel pump ? Could be that the problem ? ?

Thank you again for the help.
I will post tomorrow and see if the the exahist replacement helped.
....oh by the way I haven't bored out the intake yet I'm waiting for my header to do it I will post pictures : )

 

try larger injections and let the engine breath better. I don't care if it isn't necessary but a better flowing exhaust can only help along with a better air intake setup. Could also run a different duration camshaft to help with torque and slight hp gains. If you really want something much better a stroker or a v8 swap would be the best thing you could do. Personally I wouldn't even mess with a stroker and go right to a 5.3 swap, though that would involve more than engine modification. Goodluck!

 

Never just put larger injectors in unless you want problems. The factory injectors flow plenty well to handle intake and exhaust mods.

 

I think maybe your expectations were too high. A bored TB doesn't make a big difference anyway.
Have you measured the inlet and outlet of the throttle body? The size of the intake manifold inlet to verify sizes?

 

wouldnt going to a 4hole injector like from a neon help with his low end. with little to no flow changes?

 

if the stock in take has a 60mm opening and he put at 62mm on it wouldnt that cause flow issues?

 

The correct ones, yes. But just adding LARGER injectors would be an issue as the stock PCM/ECU can't pull back enough fuel at idle.

 

1mm around the circumference? Have you ever looked at head versus manifold ports, carb gaskets versus manifold openings? This isn't Indy car ****.

 

this is true its a tractor engine. I did look at mine and port matched the manifold and intake. I was just brainstorming ideas for him to look into. missed the part were he said he is going to bore the manifold.

 

It's not a frickin tractor engine!!!!!!!!!!!!

 

LOL. That also frustrates me. Cringe!!!

 

It's a crock of ****.