XJ top speed

[bjoehandley]

Nice GTS, I used to have an '85 T1/Auto/SH2 equiped one. It was black with gold pinstriping (actually, it looked alot like yours, just w/out the sunroof, third brake light, all the trim is chromed, and it had pizza wheels), with dark red leather! Unfortunetly, mine only had one of the 85mph speedo's, so when it passed 85, the needle would just wiggle back and forth. I finally lost it to rust and old age in June of '03. How well does yours run with the work you've done? Mine had a drop in K&N, MPP overflow injectors, MPP 8mm wires, Accel SS coil, and 3" exhaust with Dynomax 3" truck cat and 3" Ultraflow glasspack (one of the ones Gu's tested against the Worlock.)

 

[JeepsterXJ]

well, now that we've hijacked this thread, lol: She runs perfectly. The engine has 1000 miles on it, complete rebuild with only the best, total buildup was 5 years and $6000+ in the making. It has 3" exhaust all the way as well. The warlock was picked because it was quieter w/o the cheater pipe opened. I've only put 500 miles on her since last october, I need to align her after installation of the Eibachs and I'll have her on the road in the spring. I plan to take her to several shows next year. Your car sounded quite nice. Mine was actually gold trimmed, as were all the 89 GTS's, but it was converted to silver/grey before I got her and I couldn't be happier of their decision.

 

[Dr. Dyno]

I took my XJ out on a near empty highway last night and tested its top speed again. I already knew that the top speed limiter would cut in at 116mph in 4th except this time I also did it in 5th (speedo showing 195kph), and I only had my right foot at about 1/3 throttle! If I could disable the top speed limiter I could easily reach 130mph. In 4th gear the Jeep was still pulling like a freight train when it hit the limiter and it felt very stable indeed.
______________________
Dino's "Mean Green Machine"
1992 XJ Laredo 4-dr - 4.6L I6 HO Stroker - 178k miles - AX15, NP231, D35c, D30

258hp@4800/320lbft@3200, 1/4 mile = [email protected], 0-60 = 5.9secs
Websites - Jeep 4.0 Performance, 4.6L Stroker Build-Up, Dino's Jeep Tricks

 

[bjoehandley]

Wish there was enough empty roads around here to even try that Dyno, wonder what it will do with out the restricter? Good luck!

 

[Dr. Dyno]

The only way to disable it is to disconnect the wiring harness from the VSS (vehicle speed sensor). The only problem there is that the speedo and odometer won't work anymore so you'll have to rely on the tachometer to calculate your speed. I know mine is 26.6mph/1000rpm in 4th and 33.6mph/1000rpm in 5th.

 

[spazegun2213]

hmm, is there a limiter in all jeeps? I have raced past 107 (i know this because my friends ZX-2 is limited to 107) and there was never a problem. the only problem is that the speedo in my 98 only goes to 100... so umm... i'd need someone pacing me in a fast car. I have done over 100 many times in 4th gear, so i have yet another gear to go.

 

[Osprey413]

I did the math last night and figured out that the 4.0L at redline in third gear, with 235/75/15 tires, and 3.55 diff ratio, the max speed possible is 121mph. Of course you could never reach this because Jeeps a bricks and the wind resistance would slow you down.

 

[theslacker]

My 92 4.0L auto hit 170kph downhill before I ran out of road but she was still pulling hard

 

[Atl XJ]

I did the math last night and figured out that the 4.0L at redline in third gear, with 235/75/15 tires, and 3.55 diff ratio, the max speed possible is 121mph. Of course you could never reach this because Jeeps a bricks and the wind resistance would slow you down.

Mine hits the redline in 3rd at around 100 mph. You'd never hit the redline in 4th though, it'd be like 140.

 

[Osprey413]

Not enough power to go to redline in 4th. Not to mention the speed limiter. Maybe if you had a stroker and removed the limit... then you probably could.

 

[PapaPump]

Alright i know it makes me a lunatic and it's dangerours but where i'm at we have a road heading to the river that is designated quarter mile and so forth in one section. I had two friends...one with a chevelle, and the other with a corvette. The ran behind me the whole way i went down this road. Mind you i have a 91 xj 4 door HO 4.0 with auto tranny and said i was doing 130mph without the pedal to the floor yet. We were on cell phones and at the time i was doin 130 my rpms read about 3100. i am pretty impressed by the performance of it, but it aint something i do everyday seens how i have 266k+ miles on the engine. So i'm sure some yalls cherokee's can handle those speeds as well. and as far as the speedometer goes it was well past the vertical point.

okay that guy is a moron. jeeps can not do 130. they will redline in 3rd though, i have done it. I have a 5 speed so my gears are tall, but with 205/75r15s and 3.07 rear end gears, thats ends up being around 97 mph. that is not a completely accurate number of course because of the imperfections in tire sizing, but it is close. that is with the speedo pointing straight down at the mph, amybe a little past. if i could redline in 4th, it would be 138 mph, but it can't, so no i won't be challenging any 5.0s to topend tests. i do think it is unsafe on lifted jeeps especially with q rated tires (bfg mts, yokohama, most other mts)(99mph), i have h rated tires and no lift, but i dot think wagons are known for downforce either, one mistake and you are gone. have fun!

 

[ZmOz]

okay that guy is a moron.

Agreed. With the 4.0 and AW4 you'd be going about 98mph in overdrive with 225 tires at 3100 RPMs. To get to 130 you'd have to be doing around 4200 RPMs in overdrive, I doubt that's possible power wise, and the speed limiter would stop you anyway.

 

[Atl XJ]

yeah, it think they are governed at 116, I've had mine to 120 (GPS) but speedos arent entirely accurate and the faster you go the more off they are so that makes sense. Its really dangerous, and I'd never do it again in an XJ. Its dangerous to drive that fast on a public street anyway, but if you are going to do it, do it in something that is at least designed for it and has the proper tires.

 

[Mike@Accurate]

I have a '00 2 door auto. Supercharged, 8# boost & 300hp. I hold it foot to the floor untill it shuts off at least once a week. A couple of factors come into play. It won't shift into OD or Lock-up with your foot to the floor. TPS WFO and MAP 0 and it will stay in third. I did the mph/rpm thing (in 3rd below lock-up), and went out the first time. It shut off at what I thought was the rev limit of 5200 or so. If you figure in a really good slip# (truck had no miles on it when I put the S/C in), I came up with 128mph. I've been using this as my mental top speed. I recently took off the JUNK goodyears it came with, and put on a set of Michelins. Now it is so smooth at speed that I drive 20mph faster all the time. You can be going 100 with absolutely no drama. Creeps up on you. So I have been bouncing off of the limiter more lately. Then I got the 12/04 JP ragazine. "Adding 20hp to the 4.0" "Step 5 " Hypertech Power Programmer for '96-'04 X/Z/T J's. Among other cool things "Adjust your top speed limiter to 116 or 128 mph"... No poop. If ever there was an XJ that would do it, that would be me. I'm inclined to believe it. If you back off even a little it will drop into OD/Lock-up and go 125ish all day. I never did the top end run less than WFO, tomorrow I may try to ease up on the top end in OD and see if it shuts off again. That would probably clinch it.
When the S/C was on my '97 TJ 5spd it would be brutally accellerating when it hit the 116mph limit. That truck was mean. If I could unlock it's potential....shew! (1/4 in the 14's with a wheelie to the rev limit in 1st and a 1.9 60' time). It IS squirrelly though. So for the time being I'm staying with 128mph. MIKE

 

[phaythe]

Wow, I keep reading about everyone getting scared right around 100mph...I hit my gov. at least once a week...but them I'm psychotic and happen to drive deserted country roads on a daily basis...and yes, it is gov'd at 116mph...I regularly drive to the gov and back off and cruise at 110 in OD...
Hell on the freeways around here it isn't uncommon for me to have my cruise set at 90mph...

and I just so happen to own a 1997 Auto 4.0...