First post guys. Awesome forum. I have learned alot from all of you.

Anyway, I have read that the TC has a topspeed of around 127 mph because of a rev limiter or something. My question to you is; will the automatic tranny Tc post a higher top speed than the 5 speed manual because of its different final gear ratio?

 

i had an auto before... i think i distinctly remember only going up to 127 mph also before the limiter kicked in. so no.

 

Nope same top speed.

 

However, because of the drive ratio differences, the auto has a much higher potential top speed if the limiter is disabled. I can't find the charts offhand, but with the automatic, its final drive would technically allow it to get up to 165 before the rev limiter kicks in. Whereas on a manual tranny, the rev limiter would kick in slightly after the speed limiter (because of its lower final drive ratio). Only way around that is to figure out a way to get another gear in there (ex 6sp celica). Although as it stands no one has been able to do it yet.

 

So its a rev limiter that holds back the top speed. If this is true, wouldn't the limit on the auto have to be lower than the manual? If so, then it is impossible to reach redline on an automatic in 4th gear. I hit 125mph on mine before I ran out of road, but I was barely past 5k rpms. This is on the stock 17" wheel and tires. So I guess my rev limiter was about to kick in but I didn't reach it.

 

hmm.... well.. at the time i was driving my auto i do remember hitting redline..

 

In my 5-spd I reached 138 mph.

 

I failed to mention that mine is the auto tranny. If it is true that the auto has a higher top speed potential, than I did make the right choice. I prefer a car that can do 150 mph and a 1/4 mile time in the mid 14s. Looks like with the supercharger or stage 0 turbo I will be able to obtain that if I can get rid of the limiter. Currently my other car is a 1987 Pontiac Formula 350 with a auto tranny that is completely stock for the exception of a catback and air filter. I can run 14.6s all day long. I really do love the auto trannys. Yeah you give up .5 in the 1/4 but you gain consistancy. I am hoping to achieve similar results with the TC. I don't need to be the quickest or fastest on the street. I just want a fun car to cruise around in. I believe the Tc is going to do this for me.

 

No, there are speed limiters in place in addition to the rev limiters. 127mph or so is the general consensus. If you were to hack out the speed limiter electronically, the 5 speed's lower final drive ratio will bring it to redline at an earlier speed than the automatic. I'm trying to find a chart on here that basically showed the ratios for each gear, final drive, and potential top speed. The automatic runs a lower rpm than the manual at a given speed. Therefore, the manual will hit redline before the auto.

 

That chart would be great. Thanks Breakthestatic!

 

Chart is at:

http://blacktc.com/gearing/

 

Thank you, that is exactly what I was looking for. Theoretical top speed for the manual is 138, whereas the auto is 162. I'm not sure if these numbers take drag or any other factors into account. However, as you can see, the manual's short gearing = quicker acceleration, lower top speed & gas mileage. Oh well, I still definitely wouldn't ever trade my stick. Someone will eventually get a 6speed in there somehow.

 

126-127 in the 5 speed, been there done that.. :o

(on a closed test course, obviously)

 

Great info. So does anyone know how to remove the speed limiter? Any chips made yet or individual companies who will reprogram the ECU? When I was doing 125 mph the Tc was running smooth and felt like the suspension could handle more speed.

For you all out there who hit over 130mph, is that with stock wheel and tires? Maybe calibration was off. Just curious!