What RPMs Do You Shift At? (MT Owners)

[desertred]

Just curious what RPMs manual tranny owners shift their XJ (4.0L) at, and where the sweet spot on the tach is. Occassionally, my 88XJ will get a bit tempermental and want to run at a higher engine speed than normal. That started me wondering at what engine speeds other 4.0 XJ owners shift at, and what RPM range they find optimal. I know that the shift light for my rig comes on when the tach hits approximately 1250 rpm. Does the tranny make a difference (BA5/10 or AX15)?

 

[5-90]

Tranny - doesn't matter - it's the torque curve of the engine that drives things.

Shift light - I pulled the bulb on mine a few years ago. I got tired of it telling me what to do - and being wrong.

I aim for cruise at about 2600-3000rpm, and generally shift about 3800-4000 while getting up to speed. Shifting after that depends on a number of factors - mainly, how much throttle response I think I'll need, and if I'll want compression braking right away.

88XJ/4.0/BA-10/NP231/D30 (3.07)/D35 (3.07), in case you were wondering.

5-90

 

[IXNAYXJ]

What size tires/gear ratio? When my 1994 4.0 H.O. 5-Speed was stock, I would shift between 1500-2500 most of the time. Now, with 33" tires and the stock 3.07 gears it takes considerably more revs to get it going, both on and off road. I have to use 3rd gear on the freeway to pass or climb a grade...which is why I've got a set of shiney new Yukon Gear 4.56's sitting in a box at home...!

-----Matt----

P.S. I find the sweet spot in the power band between 2500-4000 RPM's. Much after 4k, it just seems to make more noise and the power dies off. But after 175k miles I guess one can't expect too much....

 

[MENEZES]

i always shift at about 2000-2500 unless someone is riding my ass or i wanna get movin quick.

 

[Kejtar]

I got a 97 with 4.88's and 33's and I shift more by feel/sound then anything else as the terrain, load kind of dicate the shifting a bit. I do know that I try to keep the RPM's under 3200.

 

[summitlt]

Trying to get the best mileage, I shift at a little over 1500. I have 215's and 4.10s so its not like im wokring to motor at all (this is the 4.0 too)

If im "racing" I usually shift right at 5K in 1st and 2nd, 3rd and 4th usually around 4300. The 1 - 2 and 2 - 3 shifts I stay til 5 k because it takes no power to go through those gears. In 3rd it starts taking time and you can feel the power drop in third a little over 4K.

 

[Colorado_XJ]

When I was cruising around town in my '90 with 3.07's on 29" tires, I'd run up to 23-2500 most times. I'd drop it a few hundred RPM's if I was taking my time on some flat ground. But that rarely happened! My "new" '99 auto likes to shift at 26-2900 RPM's around town. I am still getting used to hearing the motor rev a little higher. I need that AW4 shift knob...

-Rich

 

[R6TeXJ]

I shift around 2k-2.5k I don't want it to blow. I already makes enough noise as it is lol

 

[bajacalal]

For everyday driving, at 2500 RPM. Less than that it seems to drop too much RPM and dogs. It seems to like bieng taken out of 1st early and shifted early going downhill unless I'm decelerating. Now, for speed around 3300, and at the 4000s range thats just racin.

 

[PhilSine]

I have no idea. It seemed practical for them to have put a tach in both my 88 and 96 XJ's both with automatics but heaven forbid they toss one in my MJ with a stickshift

I will be installing a tach when I get around to it. Gotta fix her up a bit first.

 

[Eagle]

'88 XJ with BA 10/5 tranny. First to second really likes to shift at 2000 RPM or a bit less. Other shifts are about 2200 to 2300 RPM.

 

[87manche]

87 MJ with 31's, 3.07, AX-15
I've found that it really likes me to run it out to about 3000 RPM before I start my shiftg. Anything less and it sounds like I'm lugging the motor. I rarely go above 3000 RPM, but if I'm in a hurry it's 3800-4000

 

[Dr. Dyno]

I usually shift between 2000-2500rpm. At 2500rpm I'm doing 17mph in 1st, 29mph in 2nd, 46mph in 3rd, 66mph in 4th, and 84mph in 5th so that usually means I'm going faster than almost everybody else on the road.
I rarely see the need to go above 2500rpm unless I'm really in a hurry 'cause I've got so much power in reserve, but I do like to rev the engine to 5000rpm occasionally just to hear it growl through the 3000-4500rpm sweet spot and fly by slower traffic at warp speed.
__________________________________
Dino's "Mean Green Machine"
1992 XJ Laredo 4-dr - 194k miles - 20k miles on 4.6L HO Stroker
AX15, NP231, D35c, D30

265hp@4900/325lbft@3500, 1/4 mile = [email protected], 0-60 = 5.6secs
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks

Forever in the s__t. It's only the depth that varies!

 

[Kejtar]

I do believe that you should mention that this is not on a stock motor.....

I usually shift between 2000-2500rpm. At 2500rpm I'm doing 17mph in 1st, 29mph in 2nd, 46mph in 3rd, 66mph in 4th, and 84mph in 5th so that usually means I'm going faster than almost everybody else on the road.
I rarely see the need to go above 2500rpm unless I'm really in a hurry 'cause I've got so much power in reserve, but I do like to rev the engine to 5000rpm occasionally just to hear it growl through the 3000-4500rpm sweet spot and fly by slower traffic at warp speed.

 

[edmaude]

Usually 2200-2500 between all gears in normal driving

 

[Eagle]

87 MJ with 31's, 3.07, AX-15
I've found that it really likes me to run it out to about 3000 RPM before I start my shiftg. Anything less and it sounds like I'm lugging the motor. I rarely go above 3000 RPM, but if I'm in a hurry it's 3800-4000

Considering that you are shifting well beyond the torque peak at 3000 RPM, you're fooling yourself if you think you're getting better performance by shifting that high.

 

[87manche]

Considering that you are shifting well beyond the torque peak at 3000 RPM, you're fooling yourself if you think you're getting better performance by shifting that high.

I know it's past the torque peak, but if I shift at anything lower than that I really feel like I'm lugging the motor. It's real sluggish below 2000 RPM, I suspect that my larger tires and stock gearing have a major part in that. So I either need to go back to stock sized tires (not likely), or gear to 4.10 (found a source for a 4.10 MJ AMC 20 and it's matching HP30)

 

[summitlt]

Considering that you are shifting well beyond the torque peak at 3000 RPM, you're fooling yourself if you think you're getting better performance by shifting that high.

I would hope your wrong!?! Lets say your racing (yeah racing!) you think that shifting at 3 k is your best bet?! I dont think so.

 

[Rev Den]

I dont think so.

There you go...working without tools again.


Rev

 

[Dr. Dyno]

I do believe that you should mention that this is not on a stock motor.....

That's why my siggy says I have a stroker. Mind you, my driving habits were still the same even before I built the stroker. The only difference is that the stroker sounds sweeter than my old 4.0 at higher revs so it doesn't cry for mercy when I'm nearing the rev limiter.