Hey Everyone,

I have a quick question last time I raced my friend from a dead start I downshifted my car in 1st to start with then I shifted into 2 about like 50-60mph then went into 3rd and my car topped of at 110mph in 3rd gear not even red lineing yet, bearley in the orange part. I was like WTF! So I threw into 4th and nothing just my rpm's dropped and still nothing.

Is there a way on how I could fix this? I heard something about the governor not sure if this will fix my problem.

And by the way I have a 700R4.

Thanks. Tony.

 

Works great on a TBI. Dunno what the difference is, between TPI & TBI, but I would think it should be VERY similar, if not the same. I'll ask my electrical friend about it tomorrow.

https://www.thirdgen.org/unlimited

 

My problem is that I can not go over 110mph. How do I fix that?

Tony.

 

I understand that. I'm talking about the ECMs built in speed limiter.

What I posted about, is a way to keep the ECM from knowing how fast you are going. If it doesn't know, it can't limit your speed.

 

But is there a wya were I could have my speedo work and the computer lting me go over 110mph.

Tony.

 

Our speedometers are mechanically driven. So if your car shuts down at 110 (i think the the speed limiter is actually 108) then your speedometer is reading right, just the ECM is stopping you.

When you defeat the speed limiter, it has zero affect on the speedometer.

 

The 700R4 in my 88 is electronic. Run off a pulse generator driven by the tailshaft in the trans. I'm going to assume that on a 91 you would also be electronic. The pulses are run to a neon yellow box next to the ECM, where they are converted to a number that can be used by the speedometer or ECM. I believe I heard that the generator puts out E.X. 4000 pulses per mile and it then needs to be converted to 3200 to be used by the speedometer.

I'm not positive on the numbers or accuracy of all this, but is what I heard in the past. This is how they get around gearing ratios between the trans tailshaft and the speedometer besides the normal drive and driven gears that are used to account for rearend gear ratios.

I believe in the tech article section there was something about overriding the governer. I've never done it because I burned a new PROM with the speed limiter set at 255. I cannot tell you if it disables your speedometer or not though. If you do some digging, you could probably come up with a wiring diagram. I do know that it is a brown wire coming out of that neon yellow box that has to do with the speed signal. That was where the aftermarket cruise control was tied into.

Hope that helps in some little way.

 

the govenor will not affect your top speed. govenors spin and the centrifical force moves the weights out... they only affect the shift points on the trans. the govenor is not the problem. the speedo is not the problem. my 87 formula 383 and 86 TA with a 305 both have electric speedos (mechanical gear driven converter spins to pulses which is how the ECM reconizes the speed, so basically its electrical) a mechanical trans uses a cable from the trans to the speedo. its a 2 weather pack connector on the tailshaft of the trans. the only way u can get around the speed limiter is deleting it in the chip or BIN. u will need to be able to burn your own chips or get a modified chip by someone. its real easy to do... is like u highlight the limit and just type 255mph lol.

you might be able to do this... disconnect the speedo (weather pack connector at the trans tail shaft) make sure its tucked out of the way from the ground. then get a GPS if u dont already have one (uses a friends etc) and most of them have a speed MPH reading on them... 2 outa the 3 i have can do this... they are pretty accurate. then go for a drive and see if u can get above 110 now. i wouldnt recomend this but the only way to really get if fixed and use your speedo is to delete the speed limiter in the chip. i think aftermarket chips delete this. i kno with my motorvation strip chip i got up to 125 with it.

 

Thanks bro this makes a lot of sense now thanks for sharing with us, and how or who can I talk to about getting a prom burned so I could top off at 145mph?

Thanks. Tony.

 

Yep you need to have a chip burned to take the 110 speed limiter off. It is a really simple change. Are you running an aftermarket chip now? I can help you out with the chip just send me a PM.

 

Thanks for all the info guys.

jonarotz pm sent to you brotha.

Tony.