So I've been noticing something strange. MINIUSA advertises different gear ratios for the JCW compared to the Cooper S. The transmission part numbers and descriptions are different, the Cooper S calling for a "GS6-59SG - TBFJ" and part #23008617542, and the JCW calling for a "GS6-59SG - TBFN" and part #23008617543. Despite that, I made a little chart and then recorded the observed speeds per gear per RPM, and discovered something unusual. The gear ratios at least in my JCW appear to be identical to the advertised ratios in the Cooper S. Check it out; the differences are pronounced once you see 4th gear and higher.

Trans_ratios_observed by Ryephile, on Flickr

I asked my dealership for clarification, but at this point they're hesitant to help, only verifying there are indeed separate part numbers and essentially discounting my recorded observations. I need the few of you that have an F56 JCW 6MT to take my speed vs. gear vs. RPM chart and verify which ratios you have. With more information we can storm MINIUSA for answers.

Please and thank you!

 

Looks like mine is geared the same. No surprise since our cars were built on the same day.

 

Transmission While both the Cooper S and JCW use the same basic gearbox, the ratios and final drive are quite different. The Cooper S uses a 5.2:1 ratio spread, whereas the JCW has a wider 6.2:1 spread, meaning 1st is shorter and 6th is taller. Specifically:

Cooper S vs JCW
1st gear: 3.923 vs 3.923 *
2nd gear: 2.136 vs 2.136 *
3rd gear: 1.393 vs 1.276 *
4th gear: 1.088 vs 0.921 *
5th gear: 0.892 vs 0.756 *
6th gear: 0.756 vs 0.628
Final Drive: 3.588 vs 3.824

It's in the diff and the DME mapping Look at the ratios in 4th. That's why you feel what you feel.

Sent from my iPad using NAMotoring

Copied from post in MA

 

I think you're a few steps behind the situation. Let's just look at 6th gear between the two models. Cooper S final ratio is 0.756*3.588 = 2.713:1, JCW is 0.628*3.824 = 2.401:1. Quite simply from there, the JCW 6th gear will have a lower RPM for any given speed. However, what MoBoost and I are seeing is the exact same speed expected for a Cooper S, NOT the JCW.

This isn't about "feel", and the ECU is totally irrelevant. Either our cars were built with the wrong transmission or MINI advertised the incorrect ratios.

 

The article in this publication further muddies the water as it states that the S and JCW transmissions have the same gear spread.
http://www.a3ps.at/site/sites/defaul...ansmission.pdf

 

I agree Jon. Not sure if the article is accurate or the BMW press release and MINIUSA website.



Is there anyone else on here that has a JCW manual trans that can help contribute?

 

Maybe the higher 5th and 6th are for Europeans not USA. Maybe it tweaks their MPG figures or something. Sure looks like Ryephile and MoBoost got the same gears as the MCS for sure.

 

It's possible, however the ratios on MINIUSA's website match the MINI Corporate press release, attached over in my "differences" thread.

What's interesting is the advertised JCW ratios match the advertised ratios for the MINI's platform mate BMW 218d SAT [euro only], but the part numbers and trans description are totally different. Maybe BMW marketing totally messed up some technical data?

 

IMO different part number doesn't mean it's different in function. Example: sport suspension. The coilovers have different part number from regular suspension coilovers. But they're the same springs, same dampers. Go figure.

 

Um no, that particular example is not accurate in both R53 and F56 contexts.