Do 87-93's have govener speed limits?

  • Sponsors (?)


Right place to ask, fair question.

There is not limit as far as MPH. With 2.73 gears, 5000 RPM (if you could turn 5000) would take you to 200 MPH.

The engine does have a rev limiter set at 6250 RPM. It cuts off fuel to one injector at a time to keep the revs from exceeding the 6250 limit.

Cars with modified engines & 3.55 or greater gears may be able to hit the rev limiter in 4 th gear, and given enough road, they might even be able to do it in 5th. Those cars are the exception, as the power needed to peg the rev limiter in 5th gear is probably in excess of 500 HP.
 
The EEC has a speed limiter line in it set at about 127mph as well as the rpm limiter. How it does the limiting exactly I don't know, but I bet it uses calcs that depend on factory gearing set ups and such.
 
The stock suspension and aerodynamics limit the speed more than anything. I peged the speedo once or twice, which it isn't that accurate but it was scary, had that floating feeling. I don't think I will try that again.

I didn't know the speed limiter could be activated. I think that is the last option you would want when having a chip burnt.
 
If the gears in the car are stock (2.73 or 3.08), there are very few fox bodies (if any) out there that are redline limited. It would take something in the area of 550-650 HP to push the car to the redline in top gear with those gears (aod or t-5); most cars pushing that much power have long since changed the gears too. With stock gears, most cars are aero/drag limited in top gear. Even the new Corvette reaches it's highest speed in 5th gear, not 6th - it too is drag limited in top gear, not redline limited.

However, as others have pointed out, suspension and BRAKES are severe limitations to running along at much above 120-130 in the stock car, if you want to do it safely. Mods need to be made in those areas to safely run those speeds. And don't forget the tires - nice to have them hold together too.
 
Thanks guys! I was just curious because my friend has a speed limiter at like 108 or something and i was thinking that it would suck if mustangs had them that low, he drives a focus btw.
Danny
 
Most chip-based speed limits are there because of the speed limitations of the oem tire placed on the car - and the lower speed rated tires were usually used to contain costs. One exception is the speed/hp war that the Germans waged for years. In order to appease the Green Party in Germany (and their attempts at speed limiting the autobahn) most German manufacturers adhere to a self-imposed 155 mph limit in their cars' ecus.
 
yep, as y'all know, Cd is quadrupled with the square of speed (think that is right). foxes are not streamlined, so drag limited is most appropriate, most of the time.

Michael, i have a story for ya sometime about a Ruef Porsche on the A-bahn outside Koeln doing a 4 wheel lock-up at ~ 170MPH - Audi ahead of him (left lane) was not paying atttention. i think some of the smoke was from the downshift too.
once the Audi moved, the Porsche got scratch (i kid you not) at about 130-140 MPH. it was like Eleanor in the flood channel - GONE!
awesome when you are goin ~130 MPH yourself. :)
 
All good information... I have 3.73 gear in my '89 with a T5 and I went just passed 140 on my speedo one day at about 4200 rpm in 5th before i let off... my speedo gear was never recalibrated tho... my car was originally an AODbut had tha 3.73s before it was converted... any idea how far my speedo is off?
 
HISSIN50 said:
Michael, i have a story for ya sometime about a Ruef Porsche on the A-bahn outside Koeln doing a 4 wheel lock-up at ~ 170MPH - Audi ahead of him (left lane) was not paying atttention. i think some of the smoke was from the downshift too.
once the Audi moved, the Porsche got scratch (i kid you not) at about 130-140 MPH. it was like Eleanor in the flood channel - GONE!
awesome when you are goin ~130 MPH yourself. :)

Wow, I didn't understand that?? :shrug: :shrug:

Guess it doesn't really matter because it wasn't for me...haha sorry man :D
 
i got a rear axle out of a 87 thunderbird with the 3.73 and in 4th gear i hit abot 100 to 110 at 5k rpms, then when i shift to 5th it takes a bit to get past 130. probly from mainly wind resistance.
 
cjman15 said:
Wow, I didn't understand that?? :shrug: :shrug:

Guess it doesn't really matter because it wasn't for me...haha sorry man :D
we all know im scatterbrained. RUEF is a well known company that mods Porsches (think Saleen to stangs). (the name looks like RUF with an umlaut over the 'U' - i dont know how to make umlauts with a 'puter, so an 'E' after the vowel is a substitution).

when you are driving along at 120-130 mph and see a car comin up in the left lane FAST, lock up the brakes at that speed, wait, flashing lights furiously the whole time, then downshift, breaking loose at 130MPH or so, and leave you in the dust (while you are goin close to 200 clicks/hour), it leaves an impression. just the sound of the exhaust leaves an impression.
just a lame story. :)
 
cj - It's easy to know how far off your speedo was from before. It's a simple ratio of the gears. Your adjusted speedo reading should be 2.73/3.73X 140 = 102 mph. But I suspect either (or both) your tach or speedo were off before (maybe tach is still off - is it stock? They're notoriously inaccurate) because even with the 3.73's, 100-105 mph ought to be around 3500 rpm for the T-5 with 3.73's.

hissin - great story! I've spent a bit of time driving the autobahn - great fun, and you'd best be paying attention.

By the way Cd (drag coefficient) is a constant for a given aero shape - it doesn't vary with speed. It varies if you change the way the air flows around the car (fold the mirrors back, tape body seams, tape over the radiator opening a la NASCAR, change the rear spoiler height, add an air dam, etc.) And Cd must be multiplied by the aero cross sectional area to get the vehicle's drag - so two cars can have the same Cd, but if one is bigger (taller, wider, etc.), it will have more drag. It's the drag (aerodynamic force) that increases with speed. I think the relationship you're pointing to is that the power required to go faster varies with the CUBE of the speed increase. So, if it takes 190 rwhp (stock stang) to go 135 mph (average top speed for a stock stang), how much power will it take to go 200 in the same car? 200/135=1.48, 48% faster. 1.48 cubed = 3.24. So, it will take about 190 rwhp X 3.24 = 616 rwhp to hit 200 mph in the same vehicle. Approximately of course. :)
 
HISSIN50 said:
we all know im scatterbrained. RUEF is a well known company that mods Porsches (think Saleen to stangs). (the name looks like RUF with an umlaut over the 'U' - i dont know how to make umlauts with a 'puter, so an 'E' after the vowel is a substitution).

when you are driving along at 120-130 mph and see a car comin up in the left lane FAST, lock up the brakes at that speed, wait, flashing lights furiously the whole time, then downshift, breaking loose at 130MPH or so, and leave you in the dust (while you are goin close to 200 clicks/hour), it leaves an impression. just the sound of the exhaust leaves an impression.
just a lame story. :)

Theres one of those RUF Porsches on Gran Turismo 3, sweet car! Good story.