Replacing S/C Drops with helical
Turbo Mini Forums

Hallo guys,

i am currently planning my winter project and for that i would like to get the car more silent - in fact the whine from the S/C Drops is too annoying for road use, i dont want to constatly drive with ear protection.

I read in the forum that a lot of you guys run with helical drops without issues, and since i am aiming for maybe 120hp it should be possible with my engine too. Or would you worry with helical drop gears?
Question now: When buying helical drop gears - are there differences? Different brands, better qualitys etc.

Another question i am still thinking about is if i should go for the Minispares evolution helical gearset as well. I cant really tell how loud the car will be with helical drops and S/C gearbox - if its worth the money.

At 120hp, you should be fine with standard drops. If you want extra piece of mind you could use the Mini spares Evo helical drops that have recently been released.

In the 13's at last!.. Just

They have evo drops too now? Where did you see them, cant find anything about it.

The evo gear kit basicly uses wider gears to perform better - how do they strenghen the drops where de bearings are usually the issue?

Does anyone run S/C gearbox and helical drops? Whats the noise level in thes configuration? I dont mind a little whine, but i dont want to use ear protaction. Also its nice to hear the engine itself too :)

Bah!! I’m being a numpty! I was thinking of the gear set.

Standard it is, unless you want to try using the ones that Robert tried. They were from either mpi or auto.

In the 13's at last!.. Just

New primary gear bushes, and a tightly shimmed idler gear with good bearings should be fine. Lots of primary gears seem to have quite a bit of slop now due to wear which doesn’t help, let alone the thicker transfer case gaskets.

Edited by minimole23 on 31st Jul, 2019.

Ok thanks, then i will go by the standard ones.

Any experience with the noise of s/c gearbox? If that one is not too noisy it would save a lot of money and time if i dont have to take the gearbox off

Gary mine were boggo stock a+ ones , ok to well over 230 bhp .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Really. Didn’t you at least have a measure up of some from an auto?

In the 13's at last!.. Just

yes i thought about the auto ones , if i remember correctly they were huge .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Just out of curiosity - From the manuals it seems like the mini auto gearbox also uses a torque converter - like basicly all automatic gear boxes back then. The torque conerter sits befor the drop gears instead of the clutch
Shouldnt the torque converter flatten out tourque peaks and therefore reduce the load on the gearbox.
My experience is that automatic gearboxes usually can handle more torque when using the same gear sizes.
Just looked at this and the idler gear does look quite big

Phew! My memory is still slightly intact then!

In the 13's at last!.. Just

A straight cut box with helical drops will be no louder than a helical box in 4th gear, which is possibly where it matters to you the most?

Thanks :) Lets see how much budget i have in winter if i go for full helical or just helical drops