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The mkiv Supra Owners Club

Supra gearing


Syed Shah

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Someone posted this to the other list once, and I kept a copy of it.  Hope it's useful:

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'89 Supra Turbo 5sp

Transmission: 5 speed MANUAL

Gear ratios 1st: 3.25:1 4th: 1.00:1

           2nd: 1.96:1 5th: 0.75:1

           3rd: 1.31:1

Final drive ratio:  3.73:1

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'86.5 Supra NA 5sp

Transmission: 5 speed MANUAL

Gear ratios 1st: 3.29:1 4th: 1.00:1

           2nd: 1.89:1 5th: 0.78:1

           3rd: 1.28:1

Final drive ratio:  4.30:1

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'92 Supra turbo automatic

Transmission: 4 speed AUTOMATIC

Gear ratios 1st: 2.80:1 4th: 0.70:1

           2nd: 1.53:1

           3rd: 1.00:1

Final drive ratio:  3.73:1

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'93.5 Supra Turbo Automatic

Transmission: 4 speed AUTOMATIC

Gear ratios 1st: 2.80:1 4th: 0.71:1

           2nd: 1.53:1

           3rd: 1.00:1

Final drive ratio:  3.77:1

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'93.5 Supra Turbo 6sp

Transmission: 6 speed MANUAL

Gear ratios 1st: 3.83:1 4th: 1.31:1

           2nd: 2.36:1 5th: 1.00:1

           3rd: 1.69:1 6th: 0.79:1

Final drive ratio:  3.13:1

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'93.5 Supra NA automatic

Transmission: 4 speed AUTOMATIC

Gear ratios 1st: 2.80:1 4th: 0.71:1

           2nd: 1.53:1

           3rd: 1.00:1

Final drive ratio:  4.27:1

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'94 Supra NA 5sp

Transmission: 5 speed MANUAL

Gear ratios 1st: 3.29:1 4th: 1.00:1

           2nd: 1.89:1 5th: 0.78:1

           3rd: 1.28:1

Final drive ratio:  4.27:1

 

Mk3 NA  225/50/16 = 24.86" DIA = 1.036' R

Mk4 NA  245/50/16 = 25.65" DIA = 1.069' R

Mk3 T   225/50/16 = 24.86" DIA = 1.036' R

Mk4 TT  255/40/17 = 25.03" DIA = 1.043' R

 

Using these gear ratios and tire/wheel sizes you can calculate engine rpms at a given vehicle speed or speed at a given engine rpm.

 

                     RPM                    

MPH = 0.0739 * --------------------    RPM = MPH * Gear * Rear * Tire * 13.531

               Gear * Rear * Tire            

For example a '92 Turbo Auto moving 80mph in top gear:

 

RPM = MPH * Gear * Rear * Tire * 13.531

 

   = 80.0 * 0.70 * 3.73 * 1.036 * 13.531

 

   = 2928 rpms

Another example a '95 TT 6 speed at 6500rpms in top gear:

 

                      RPM                    

MPH = 0.0739 * --------------------

               Gear * Rear * Tire  

 

                     6500

   = 0.0739 * --------------------

               0.79 * 3.27 * 1.043

 

   = 178.3 mph

Same thing with a '93.5 TT 6 speed at 6500rpms in top gear:

 

                      RPM                    

MPH = 0.0739 * --------------------

               Gear * Rear * Tire  

 

                     6500

   = 0.0739 * --------------------

               0.79 * 3.13 * 1.043

 

   = 186.3 mph

Remember this has nothing to do with having enough power to overcome the resistances at these speeds. These formulas merely show the relationship between vehicle speed and engine rpm.

 

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  • 7 years later...
Guest r34nel

I know this is an old thread but with the auto having longer ratios does'nt that make it feel slower? theres alot of debates about auto vs manual and all that but surely an auto is slower in a given gear than a manual but maybe not that much different 0-60 due to it being able to acheive a higher speed in a lower gear if that makes sense? so id imagine an auto has less pull in each gear than a manual and feels slower but can do a similar acceleration time due to staying in lower gears, thing is im less concerned with drag racing and all that, so long as a car feels fast im happy but this 4 speed long gear ratio stuff with auto's annoys me as I can only drive an auto cos I naffed my leg up crashing a motorbike when i was 18!:help: sorry for bringing up this subject which has been covered many times, but I wanted to add my piece!

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I would recommend you drive one of each, then let your arse dyno explain the differences to you :)

 

But basically, the auto is yes longer geared but the way it uses revs and the torque converter allows it better use of the powerband + the gear changes are slicker.

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Guest djernest

I dont no if tis is the right place to post tis question Anyways my engine warning light goes on & my car misfires when i accelerate above 2RPM I guess tis means a tranmission Prob?

Plz help

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I dont no if tis is the right place to post tis question Anyways my engine warning light goes on & my car misfires when i accelerate above 2RPM I guess tis means a tranmission Prob?

Plz help

 

I would suggest you start a thread of your own, as this thread will not deal with your problem.

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I dont no if tis is the right place to post tis question Anyways my engine warning light goes on & my car misfires when i accelerate above 2RPM I guess tis means a tranmission Prob?

Plz help

 

In the spirit of helping since my last few post haven't been helpful, do a search on engine codes and pull them out...start there :)

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It is the combination of auto box and its accompanying diff that makes the auto such a great car. The auto box in the MKIV is still one of the smoothest auto boxes around. The changes are perfect, giving a driving experience that other manufactures only dream about.

 

If top speed is not an issue, the auto diff on the back of a manual box makes the car much quicker. With my raised rev limit,(8500) I have a theoretical maximum speed of 212 with the auto diff and 245 with the manual. The big gain is in acceleration. I might put the manual diff on just to try a top speed run, but for now 212 is far more than I need. If I can get traction 0-60mph in sub 3.9 seconds is attainable with only 44kg of weight saving.

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Jamie its the extra RPM that makes all the difference. I am thinking of pulling the motor to rebuild it, to enable even higher RPM. I know of one MKIV with an 11000 rpm limit, just think of the possibilities:blink::blink::blink::eyebrows:

 

I am keeping my manual diff for now as I want to try one top speed run just to see what it can do, but not until I have the suspension and geometry to cope.

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