It wouldn't surprise me at all if the computer won't give you wot under a certain rpm.

 

ok let me back up...I was rolling down the highway at 70. I tried gears 4th through 6th. I don't know when the last time you had your jeep in 4th going 70 with 3.73's out back and 32" tires, but thats a shit ton of rpm. I even briefly tried 3rd, but that was about redline and honestly didn't keep it there long enough to see what was going on. Don't make me bust out my data logger to show yall what is going on.

Summary-no matter the rpm, the jk will not go 100% WOT

 

I would bet at a higher altitude (where the air is less dense) it would open the throttle fully, trying to get more air in. Like you said though, in 4th gear, doing 70, with the high RPM, I don't see why it wouldn't open all the way.

Try asking a master mechanic (or whatever their title is), because I would also bet that it isn't just your jeep, but possibly all newer cars that have the same computer logic.

 

I would guess its software limited. We all complain about how underpowered the Jeep is. A simple solution to that is to use all the available performance in the engine you would think

 

Again, just adding more air won't do anything if the motor can't use it.

The computer is constantly monitoring manifold pressure, O2 sensors, load, and other factors. It's more complex than just dumping more air and fuel into the cylinders. If it can't efficiently make more power with the available and and fuel, it's going to let the rpms rise before giving more of either.

I think it boils down to two large limiting factors:
1) intake manifold design. The intake manifold is optimized for midrange torque and not top end hp. Once manifold pressure rises to zero vacuum, the manifold cannot efficiently use more air volume (unless you add forced induction).
2) emissions. Just dumping more air and fuel into the cylinders beyond the efficiency range will result in higher emissions, which much of the programming is trying to avoid. I'm sure aftermarket programmers help with this, but they don't eliminate it.

I have the procomp/hypertech tune on 87. From watching my vacuum gauge and feel, mine is still limiting throttle opening on the highway to varying degrees. But it is always once vacuum reaches zero.

 

bingo. the engines biggest concern is emissions. power is almost just a bi-product

 

interesting thought on manifold pressure. I'll have to set everything up to take a look at that data and see. I agree, if the pressure reaches 0, then its maxed out. Good thought!

 

Did some data logging on the way to lunch. It appears y'all are right. It maxes out manifold pressure way early.

 

So change out the intake manifold for more power. If they make one for it.

 

this is good info.

so would it be possible to create more vaccuum somehow

is intake design the only way or larger throttle body or a spacer wich I always thought were total snake oil

as I understand it, the throttle plate isn't open all the way because it doesn't need more air.(perfect fuel to air ratio)

adding more fuel won't help at this point because you are at 0 vac.