Eck

Not that it really matters, I'm just curious as to why this is happening? So I took my car out for another top speed run the other day in an attempt to break my previous record of 147 MPH which was done with only Hypertech programming and a Flowmaster muffler.

So it went like this. I got up to speed, hit 147 again doing 5800 RPMs in 3rd gear. It took forever to shift -- it just stayed at 5800 RPMs for like 3 seconds straight. Finally it shifted, now doing 4000RPMs in 4th gear, still doing a steady 147 MPH, with the gas pedal still to the floor. It won't budge any further.

I know the car isn't lacking power to accelerate, it was doing fine until it got to that point. Well at least the HP is still high in 3rd gear at that RPM and my TQ is still very high in 4th gear at that speed. I have the top speed limiter disabled. This makes me wonder is there some sort of global speed limiter that cannot be overridden for 93-97 cars? What else could be causing it to stop accelerating?

Once again, not that this is a major concern as I'll probably never drive that fast again, but rather I'm just curious.

KeVMaN

that's weird mine did ~160 (estimated speedo ends at 150) totally stock. I don't think there's any kind of limiter

30696bird

Here's a worthless reply but....................you're a MORON! You will kill you or even worse someone else at thos speeds. Get some REAL mods and go to a track!

speed76demon

o like you have never went that fast It's hard to lay off the gas when you have a car like we do.

Bro not sure what the problem is but maybe soembody here could help ya out. I know if you would get a CAI and some better flowing exhaust that will help the top end out for sure

madwolf

I think your speedometer may not have been showing accurately at that speed.

According to a gear/speed calculation program, you should have been around 160 at that RPM. The 4th gear RPM also checks out to 160 (4000)

According to another program, you should be able to do 166 MPH with what you have.

107

Hmm, before programming my car(also A4 w/ 2.73's) shifted into 4th at 140. Something doesn't seem right. I too passed the 150 mark on the speedo when it was stock.

Maybe your gauge is off as madwolf suggested.

med_reject

im not sure why your rpm and speedo do not match. With 2.73 gears, i would expect that a stock lt1 would have a hard time pulilng 4th gear to 150+mph. Wheras with 3.23 gears you should be able to do 155-157mph at around 4900 or 5000 rpm (with stock converter), which is right at your power peak. With the 2.73 gears, you cannot reach your power peak in 4th gear so you wont be able to go as fast as with the 3.23s

96m6lt1

you should have no problem with 160,btw was your tach showing an increase while speedo wasn't?i took my m6 to 165 via GPS,had more in it not much but i was flyin for too long at that speed so i backed off..

med_reject

but he has an a4 with 2.73s.

Eck

Well, while the speedo was at 147, the tach was at 5800 or so in 3rd. Then it shifted into 4th gear, and the tach showed 4000 and wasn't moving. The speedo never budged.

From what you guys have said I guess the only thing it could be is that the speedo is off at higher speeds. Oh well, that's good to know.

med_reject

5800 on the tach in third, with 2.73 gears works out to 147mph with my calculations, cuz third gear was at 125mph at 5800rpm in my a4 with 3.23 gears (try working it out). Your speedo is not off, you simply can't pull overdrive with 2.73 gears at those speeds, not with a stock lt1.

stereomandan

Sorry, I miss the point of seeing what your top speed is. Are you racing on the salt flats, or an oval track that supports those speeds? Unless you have a death wish, is there really a reason to check?

Dan

blind527

Even thought it IS hard to lay off the gas with our cars, stock or not, going top speed on public streets is just idiotic. I would NEVER do that. I WOULD on salt flats or an oval track, but never on the street. I don't know what my top speed would be though.

madwolf

http://www.f-body.org/gears/

was 100% accurate on my 3.23.

speed_demon24

That doesn't take into account the convertor slippage though...