So I was wondering has anyone changed there gear ratio in there trany yet for better acceleration. Iam looking at changing mine to 4.54. Any thoughts on this?

 

Somewhere I thought I read the R50's final drive is somewhere near 4.3-4.4 to begin with. Going to 4.54's wouldn't be much of a change if what I read was correct.

 

hmm I dont know what the final drive is but Iam hoping someone out there can help me figure out how to get alot quicker a[FONT=Calibri][SIZE=3]cceleration. [/SIZE][/FONT]

 

The shorter final drive would definitely make the car accelarate faster - it is THE most direct way to make the car quicker. Changing to a shorter final drive means more torque multiplication to the wheels.

There is a downside to changing gears, though: You'll be turning higher revs on the freeway, and fuel economy will suffer. Also your speedometer/odometer will be out of calibration.

This would be an expensive modification, too, as changing the gears is very labor intensive.

 

Here ya go. Helix offers lower final drive for the R53 S but nothing listed for the R50. Dosen't mean you can't get it but its gonna be hard and expensive. Scroll down to the bottom to see it.
http://helix13.com/mini/products/suspension-chasis
Wanna go faster? You, me and all other Non-S drivers who want to go faster may not want to hear it but trade it in for an S. It's either that or build it to the nuts which NA is about 150-ish at the wheels. Then spray it. By then you are 3k+ into the motor.

 

I sent them a request concerning this kit and they have not answered whether this kit fits facelifted R53 or not and what gear ratios it has. On the picture the crown gear counts about 89 teeth. That is corresponding to the teeth number of the facelifted R53. Is this kit is just for convertion of old gearbox to facelifted one? But they write that "It uses straight cut gears so the car is a little louder with that race-car whine". It makes me think that it could be something different.
Has anyone applied this stuff?

 

Instead of screwing with the tranny, maybe you should first try going with a set of lower profile tires? It definitely lowers gear ratio and accelerates much quicker. I have a set of 195/55/15 Kumho ASX tires on my holies and the acceleration is quite a bit quicker than stock tire trim (175/65/15 for those who didn't know )

 

For some events I use 195/45-15 and 205/40-16 That has spoiled me!

 

Ditto. I run 205/50-15 for two summers and it gives me smiles on local streets. It's 6% undersized.

It accelerates so much quicker especially on the 1st and the 2nd gears. It can overcome the traction of my sticky ultra-high performance summer tires anytime on the 1st and the second gears, and sometimes 3rd gear too.

Only pitfall is the highway, it revs higher and more noisy.

 

If you want to go beyond lower profile tires and are going to race the car in a class that will not let you swap to a 6-speed, there might be an alternate ring & pinion from another production car. The 1.4 Liter Rover/MG ZR105 uses an R65 transmission with the exact same gear ratios as our R50's but the final drive is a 4.29 instead of the 3.94 in the Mini R65.
There were not a lot of these made, so it could be difficult to locate one, but it might be worth researching.

OEM 5-Spd (R65) MINI transmission ratios

1st - 3.417
2nd- 1.947
3rd - 1.333
4th - 1.054
5th -.854
final drive- 3.94

 

After looking at that previous post, which is very informative, I would opt to try the lower profile tires first and see what I thought about the car afterwards.