Car shuts off at 98!!!!!

[1BADAOD]

Ok guys, I have a 99 Mustang GT Auto. For some stupid reason, the car will not go past 98 MPH (acts like its hitting a rev limiter). I was told the car was sopposedly a former rental car. Anybody got any ideas where they would put some kind of speed limiting module???


I already had the computer completely cleared and reflashed/updated by ford. Also, on my predator my speed limiters are turned off and rev limiter has been raised. Any suggestions?

 

[UhadMEatGT]

It sounds like they have something on there. But how does your sig say that you go "99 Mustang GT - 13.43 @ 103" when you can only go 98?

 

[poorcollegekid]

Ok guys, I have a 99 Mustang GT Auto. For some stupid reason, the car will not go past 98 MPH (acts like its hitting a rev limiter). I was told the car was sopposedly a former rental car. Anybody got any ideas where they would put some kind of speed limiting module???


I already had the computer completely cleared and reflashed/updated by ford. Also, on my predator my speed limiters are turned off and rev limiter has been raised. Any suggestions?

ok...im ASSUMING that this car is the same one in your sig...and there it says you've hit 103....so im confused. anyway...ill act like i didnt see your sig and go on. the way the auto stang is geared 4th is a dog...if youre in 4th and trying to climb...good luck...it takes forever but even my non PI would hit 147...if the computer has been cleared...i dont know what it could be...good luck with it though.

 

[Master_Chief]

I am not sure- took mine to 130 two days ago, I don't know if it has a limiter

 

[hotmustang331]

Try looking under the dash behind the shifter...like take off the cover around the shifter, could be there. I also find it funny that you already been to the track and went 103 when its limited to 98. Unless this just happened for no reason, then I would say the car is in some sort of a safe mode.

 

[triggz]

you'd have to have 4.10s for that to be the right mph for OD, but maybe the OD band in your tranny is wasted?

will it shift into OD at all?

 

[tomustang]

did anyone mention you went 103 in the quarter?

 

[Kilgore Trout]

 

[CanadaStang]

ok...im ASSUMING that this car is the same one in your sig...and there it says you've hit 103....so im confused. anyway...ill act like i didnt see your sig and go on.

 

[Mossberg]

Self ownage alert! Self ownage alert!

 

[tjm73]

You do realize that momentum could potentially add speed even after the 98 mph speed is reached, right?

5 mph isn't that much.

I can push the clutch in on my '98 when I'm accelerating hard and before I can complete the shift from 3rd to 4th I've gained 10 mph.

Do you remember HS physics? A body in motion, tends to stay in motion. If it's still accelerating, it's gonna continue to accelerate till some force slows it down.

 

[jstreet0204]

You do realize that momentum could potentially add speed even after the 98 mph speed is reached, right?

5 mph isn't that much.

I can push the clutch in on my '98 when I'm accelerating hard and before I can complete the shift from 3rd to 4th I've gained 10 mph.

Do you remember HS physics? A body in motion, tends to stay in motion. If it's still accelerating, it's gonna continue to accelerate till some force slows it down.

Ummm, you need to check your facts. momentum and acceration are not related. Acceleration requires force. let off the gas and the only forces acting on the car are friction and gravity. Momentum will keep an object at its current velocity, until forces act on it to either accelerate, or decelerate it.

 

[mrvax]

Ummm, you need to check your facts. momentum and acceration are not related. Acceleration requires force. let off the gas and the only forces acting on the car are friction and gravity. Momentum will keep an object at its current velocity, until forces act on it to either accelerate, or decelerate it.

Nicely stated and quite correct.
Still, the car in the original post says it went 103 in his sig. I think the car stops at 98 now so he won't kill himself or other innocent people.

 

[CanadaStang]

Ummm, you need to check your facts. momentum and acceration are not related. Acceleration requires force. let off the gas and the only forces acting on the car are friction and gravity. Momentum will keep an object at its current velocity, until forces act on it to either accelerate, or decelerate it.

Not to mention that the car in question is also an auto!!

 

[tjm73]

Acceleration requires force. let off the gas and the only forces acting on the car are friction and gravity. Momentum will keep an object at its current velocity, until forces act on it to either accelerate, or decelerate it.

Then please explain to me how my car continues to gain speed even after I have removed engine forces by depressing my clutch, disconecting forward motion providing power.

When I push the clutch in at 70 mph while accelerating hard, the car continues to gain speed, all be it at a slower and slowing rate. Yet it is still gaining speed. An additional 5-10mph is the norm. It still has a momentum from stored energy that is still being applied.

You have confused and intermingled true scientific principles with what I was trying to explain in plain laymens terms.

 

[tjm73]

Not to mention that the car in question is also an auto!!

Actually this ability to continue gaining speed even after letting off is enhanced with an automatic. They, by design, store energy in the fliud within them and then distribute that energy in, for lack of a better term, a smoother way. Ever hit the gas in grandma's car and nothing happen's for a second or two? Well something is happening. Energy is being stored and it will be delivered even if you let off.

With a stick the engine is pysically connected to the transmission via the clutch as long as the clutch is engaged. When you let off, the engine adds a large ammount of immediate force slowing the car.

The car will continue to accerate until frictional forces overcome the stored energy and then the car will stop accerating completly and start to slow down.

 

[jstreet0204]

Then please explain to me how my car continues to gain speed even after I have removed engine forces by depressing my clutch, disconecting forward motion providing power.

When I push the clutch in at 70 mph while accelerating hard, the car continues to gain speed, all be it at a slower and slowing rate. Yet it is still gaining speed. An additional 5-10mph is the norm. It still has a momentum from stored energy that is still being applied.

You have confused and intermingled true scientific principles with what I was trying to explain in plain laymens terms.

Newtons laws say it ain't happenin. So maybe its an act of god if that is happening for you. Other wise I would look for a simpler explanation like the momentum of the speedo needle as opposed to the continued acceleration of the car.

Any stored energy, which would be minimal in metal driveline parts is going to go the way of least resistence. In which case would be released on the open driveline when the clutch was released. Not through the axles.

 

[DaNd4Speed]

wow, this whole thread stinks of BS!

 

[tjm73]

Newtons laws say it ain't happenin. So maybe its an act of god if that is happening for you. Other wise I would look for a simpler explanation like the momentum of the speedo needle as opposed to the continued acceleration of the car.

It sounds as if what you are proposing is that if I floor my car and run it up to say 80 mph and let of it will immediatly stop accelerating at that speed and not go one bit faster. Or if I get to that speed and push the clutch in it will immediatly start to slow down.

That is absurd and I suggest you go out and try it before you tell me "Newton's laws say it ain't happenin".

In physics, momentum is the product of the mass and velocity of an object. If it's gaining velocity at a rapid rate, even taking power away, it will for a short time continue to have momentum. And given the mass of the object it can still gain speed until friction over takes the available stored energy and starts to slow it down.

 

[tjm73]

Take a 10" diameter 1" thick "wheel" of steel. Accerate it at a constantly rising rate and then abruptly take away the accelerating force. For a short time the wheel will continue to accerate due to it's mass.