Topic: HIGHWAYs and the 2.5L YJ

[MechanixRage]

So I just got this vehicle about 5 days ago and I have noticed that passing on the highway is not a good idea since putting the pedal to the floor doing 100 km/hr really does nothing and as I have been reading in your forum it seems normal, also I have a completely stock 1994 2.5L YJ, so my question is:

Do you get a noticeable difference in performance @ highway speeds with the upgrades you guys have listed; the ones I am refering to are the electric fan conversion, the 4.0L throttle body, etc.

[jonzjeepyj]

To give us a base line for comparison.....

What size tires
What's your gearing
and how fast is YOUR highway speed / Trust me,  Mine is over the legal limit.  LOL


Just to check....     
Quote   "also I have a completely stock 1994 2.5L YJ"

[Jeffy]

Passing at 62mph is going to be a PITA even with mods.  Takes planning ahead too.  The mods should help since you won't be topped out at 3700RPM though.  Really though, aerodynamics come to play at high speeds more them mods.  The engine will have to work and so will you.

Gearing is the number one concern, although you said you're stock.  Hard top, soft top or no top?  The best for high speeds is the hardtop even though it's heavier.  It's 4" shorter then the soft top and does not flap or catch the wind.

Tire size?  Stock tires are usually 205.75R15's.  Anything larger will affect the speedometer and rolling resistance.

Speaking of aerodynamics, the front wheel openings act like giant collectors so if you could seal off the front, you'd get better performance.  This is actually what they did with the TJ for Europe.  I believe there is also laws against having the opening between the bumper and the fender.

Still, the mods that have been mentioned on the forum do help.  Most are pretty inexpensive as well.

[TahoeYJ]

Passing at 62mph is going to be a PITA even with mods.  Takes planning ahead too.  The mods should help since you won't be topped out at 3700RPM though.  Really though, aerodynamics come to play at high speeds more them mods.  The engine will have to work and so will you.

Gearing is the number one concern, although you said you're stock.  Hard top, soft top or no top?  The best for high speeds is the hardtop even though it's heavier.  It's 4" shorter then the soft top and does not flap or catch the wind.

Tire size?  Stock tires are usually 205.75R15's.  Anything larger will affect the speedometer and rolling resistance.

Speaking of aerodynamics, the front wheel openings act like giant collectors so if you could seal off the front, you'd get better performance.  This is actually what they did with the TJ for Europe.  I believe there is also laws against having the opening between the bumper and the fender.

Still, the mods that have been mentioned on the forum do help.  Most are pretty inexpensive as well.

I always forget that my hard top makes it much easier to cruise at highway speeds. I never used my soft top and recently sold it but topless it takes some extra effort to push my rig down the freeway, but it's not much. I easily run down the highway at 80 MPH, I installed some 19# injectors Monday and gained a little more than I expected with 'em. I figure at highway speeds they should help a lot since I noticed the most gain mid-top end. Won't be going over 70 before I get my 5th gear fixed though 

And as Jeffy said, all the mods are relatively inespensive, and in conjunction make a noticeable difference

[MechanixRage]

Its a 1994 2.5L YJ, Hard Top, Stock Tire size and wheels, stock gearing.

I just find it really odd that being on the highway and pushing the pedal straight to the floor the rpm's don't move at all, its like I didn't push it at all.

[Jeffy]

Its a 1994 2.5L YJ, Hard Top, Stock Tire size and wheels, stock gearing.

I just find it really odd that being on the highway and pushing the pedal straight to the floor the rpm's don't move at all, its like I didn't push it at all.

Are you in 4th or 5th?