Anybody ever put their 5.4L (or 4.6L) Ford to the floor to see where the speed limiter is set?
I took a little high-speed road trip to Utah a few weeks ago and on a nice stretch of deserted road I put my 5.4L to the floor!! It's a 2000 E-150 with the 4R70W auto tranny, so with a little help from gravity (down hill) I found out where the computer steps in and says "NO MORE". At 92 MPH the computer shuts down half of the injectors and at 97 MPH the computer shuts down the injectors completely AND locks up the torque converter? (That's plenty fast enough, no need to get a new chip burned to raise the speed limiter) Is that about average?

 

 

No just average... but on all of them. The top limit is 97 mph, except on the Lightning.

 

Ken, I'm not sure all of them cut out at 97mph anymore - I talked to one of our Ford engineers, and he claimed some of the new ones cut out at 105mph.

I'm not entirely sure when mine cuts out (2001 4.2L with the manual tranny), though I did take it out once just to see what it would do. The needle goes past 100mph, and hits the pin built into the speedo face at about the equivalent of 102mph (no markings above 100). After it hit the pin, I held it to the floor for about 30 seconds and it seemed to accelerate a bit further - and I never noticed any engine cutout at all, so unless it's so smooth I didn't notice it it's either higher (maybe 105) or the manual tranny 4.2L doesn't have one. I did that in 4th gear one direction, and then turned back and did it the other direction in 5th with the same result - and I was impressed that the V6 had enough torque to pull 5th past 100mph w/a 3.08 rear end ratio. However, I still wish they made the old 300 straight-6 instead...

Oh, and I've checked the speedometer calibration and it seems to be accurate within 1mph. I wish I knew someone with an accurate radar gun that I could use to check the true top speed...other than the cops, of course.

And before anyone asks, I don't normally drive nearly that fast - but I did want to know where the cutout was, so I went out to a seldom-used section of interstate very early in the morning when nobody else was around.

LK

 

good question. ive had mine well over 105. was over 100 and rpms still moving fast. 99 f150 offroad. then read article somewhere in here stating that due to high clearance if u drive over 100 your truck can become airborne at any little bump. whoaaaa!!!! i know it doesnt shut off at 97 cuz its been over 100 half dozen times. be a bummer as ur passing someone doing 98 and it shuts down on u!!


i only did my over hundred on a county road that is new and i grew up on so ive driven on it for 17 years now.

 

Here's what I've heard:

85, 92, 95, 97, 105, 120, etc. However, all I can find officially (shop manual) is 97. But.... this can certainly vary by ECU, but typically stays the same for an engine/year combo.

 

[updated:LAST EDITED ON 07-Jan-02 AT 09:46 PM (EST)]You guys want to know the easiest way to find out how fast your truck is?

Screw the radar gun - get a GPS unit. You can pick these up for a 100 cool ones and they are great for many other uses. I would recommend having a passenger read the thing though at speed. It is way more accurate than your speedo but you will need to hold the speed long enough for the unit to triangulait between the satellites. Which in most case ain't very long. A second or two will do.

 

Good point about using a GPS unit - I hadn't thought of that. I don't happen to own one myself, but I do have a friend who does...and since he has a laptop computer that hooks to it, I might be able to get it to automatically record the highest speed (so I wouldn't have to have someone reading it).

If my truck had a tach, I could at least get a guesstimate figure - but it didn't come with one from the factory, and I haven't gotten around to installing one. Why does Ford sell manual-tranny trucks without a tach? Maybe tachs "confuse people", just like they claimed the old (real) oil pressure gauges did...

LK

 

My speedo stops at 100 so, I added my own markings.

I've had it up to MORON several times.
Twice I reached IDIOT.
One time I got it up to DAMNED FOOL and it started to hesitate.

 

I gotta agree with LK here.

A tachometer is a must with a man. tranny. Also, would you want a fuel gauge that just said "Hey, I have fuel" instead of "Hey Idiot, I am on E and you are about to be hitchiking?"

Probably not. So why they took away the oil pressure gauge is beyond me? Maybe all the yuppie *******s that buy pickups for toys and drive the price up for everyone who needs them couldn't understand what that was and felt offended by it....

 

Speedometer and Fuel Gauge are required, everything else is a Luxury item. True for most all manufacturers.

Info can be passed via idiot lights.

and you're close on the oil pressure situation. Ford got complaints from owners wanting to know what was wrong with their vehicle when they stopped at a light and the oil pressure dropped.

Now you get an oil pressure idiot light or the optional oil pressure idiot gauge.

 

OK I ran my 2002 Screw up just to see....in the interest of science you know!!! at just a little over 100 (I'm guesstimating 105) it started shutting down injectors. Yes I realize thats faster than anyone usually needs to go but I have had situations when it was neccessary to run faster (injurys and other emergencies). Thats why I'm looking into a chip. Later Whit

 

My 01 F150 4.2, 5-spd hits at 97, I tried it for kicks, had a T-Bird before and never hit the speed limiter, boy did that speed limiter hit hard in that truck.

 

I have the 4.2L V6, but it has the auto tranny. I was on a road tripn with my friend in Cali, and we were passing a big long line of sunday drivers. I had never before known that my truck had a speed limiter until I got it up to around 94-95 mph. Once I hit that speed, the injectors shut down and it felt like someone had shifted my truck into neutral (because I decelerated so fast).

I've been hearing you guys talk about 97 being the limit, but I've never gotten my truck up to that mark personally.

 

My 02 SCrew 4.6,will hit the peg which is 105 prox on the speedometer. Strangely, mine just doesn't go any faster like a governor- no miss, loss of power, just won't go any faster. I run it from Knoxville, Tenn. to Lake Charles,La at that speed and it didn't miss a lick. Got 18 MPG's too.