• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Fastest XJ

My speedo said I was doing 195kph (122mph) but I was actually doing 116mph when the top speed governor cut in (and scared the shite out of me 'cause of the sudden drop in speed).
 
boise49ers said:
Your 6'8" and you drive an XJ ? ? ? That is a tight fit.
Click to expand...

I'm 6'7", and love my XJ, fits like a glove!

Now, back to the thread. . . .

jfox21 said:
does the governor run off of a separate spedo gear? im confused how it can be correct if your speedo isnt.
Click to expand...

There are two circuits(?) that initiate the governor: the first kicks in when activated by the tach/rpms, and the second activates when you hit the limited speed setting.

Both are tied in to the electronic ignition system, which has the governor built into it.

Switch out your ignition system for a MSD unit and you can set your rpm limitor where ever you want. I'm not sure if that affects the speed limitor.

And at any point in time I've been incorrect, please, Dr Dyno correct me.
 
SBrad001 said:
I'm 6'7", and love my XJ, fits like a glove!

Now, back to the thread. . . .



There are two circuits(?) that initiate the governor: the first kicks in when activated by the tach/rpms, and the second activates when you hit the limited speed setting.

Both are tied in to the electronic ignition system, which has the governor built into it.

Switch out your ignition system for a MSD unit and you can set your rpm limitor where ever you want. I'm not sure if that affects the speed limitor.

And at any point in time I've been incorrect, please, Dr Dyno correct me.
Click to expand...

I'm no Dyno, but the governor is electronically limited by the computer. I used to have an MSD 6AL, and it automatically cuts off the ignition above a certain RPM. But if your computer isn't sending a signal to spark (and it wouldn't above its set limit), the setting on the MSD would have no effect.

I believe I had my MSD set to 5500 or 5750 or something. I of course never hit this RPM.
 
AFAIK, the rev limiter and the top speed governor are activated in different ways.
The rev limiter is controlled by the computer and it cuts the spark. It presumably gets the rpm signal from the CPS so I don't think there's any way to disable it without losing the spark fom the coil altogether. If you have another ignition system e.g. MSD, you probably could do it.
The top speed governor gets its signal from the vehicle speed sensor in the output shaft housing behind the transfer case. When the road speed reaches a predetermined point (~116mph with stock tires, higher if you have bigger tires), the governor shuts down the fuel pump (not the spark) and it feels like a rug has suddenly been pulled from under you. It's quite scary. If you disconnect the wiring harness from the sensor, this should disable the governor but you'll also lose the speedo and odometer function.
 
Not many places to race here in Albany, NY. On a straight section of I-787 I had just gotten the speedo pegged (100 MPH) when I caught a glimpse of a po po coming down an on-ramp. Thank God for manual tranny engine braking!!!

'98 4.0L Sport, 5-speed, bone stock, 3.07 gears.

"When it comes to being the soothing light at the end of your tunnel, its just a freight train coming your way." - James Hetfield
 
db209_2000 said:
Not many places to race here in Albany, NY. On a straight section of I-787 I had just gotten the speedo pegged (100 MPH) when I caught a glimpse of a po po coming down an on-ramp. Thank God for manual tranny engine braking!!!

'98 4.0L Sport, 5-speed, bone stock, 3.07 gears.

"When it comes to being the soothing light at the end of your tunnel, its just a freight train coming your way." - James Hetfield
Click to expand...

A 5-speed 4.0, even a stock one, should be capable of more than that, I would think. I know my brother's bone stock 99 AW4 doesn't have anywhere near the torque mine does, but it still feels stronger than 100. Then again, I figure I have about 15-20RWHP more than stock, and I don't think I've hit the governor yet (no "rug being pulled out from under you" feeling).
 
My Kick-A$$ '85 Chief with the GM 2.8 v6, tops out at over *65MPH*!

It feels like 178MPH. ssssssh-boom!!!..................

Tom in KY, hangin' on with white knuckles. (gotta wear gloves or they'll blind me.)
 
db209_2000 said:
Not many places to race here in Albany, NY. On a straight section of I-787 I had just gotten the speedo pegged (100 MPH) when I caught a glimpse of a po po coming down an on-ramp. Thank God for manual tranny engine braking!!!

'98 4.0L Sport, 5-speed, bone stock, 3.07 gears.

"When it comes to being the soothing light at the end of your tunnel, its just a freight train coming your way." - James Hetfield
Click to expand...

I'll bet it's a Wrangler, which would explain it with worse aerodynamics and everything. Could be wrong though.
 
I've wraped the needle back around past the M on the MPH on the bottom of the idiot light cluster on my way home from night shift at 3 am this summer and it was still climbing back up toward the 0

Officer - "Son do you know how fast you were driving?"

Me - " Honestly, no...85+?"
 
Officer- Yeah, that'd be a safe bet. Driver's license please? *pulls out lighter*
 
60thAnivrsryXJ said:
Automatic transmissions have engine braking too. Thats what manual 3rd and manual 1st/2nd are for on the AW4.
Click to expand...

And nuke your already frail tranny mounts (take it from somebody who drives his XJ like a McLaren F1).....
 
You must log in or register to reply here.

Similar threads

Root Moose
Restoring a Uniframe
Replies
7
Views
504
DirtySouthXJ
D
D
Does This PDC Belong In An XJ?
Replies
4
Views
226
DirtySouthXJ
D
D
Specific Moab Wheel On XJ
Replies
16
Views
364
DirtySouthXJ
D
N
  • Locked
Cheap Shocks For the XJ
Replies
0
Views
48
NAXJA_Archives
N
Lost_Wrench
Strange Starter Noise
Replies
10
Views
104
Saudade
Saudade
Back
Top