Mini Final Drives Explained

We take a look at the various MED crownwheel and pinion kits.
www.med-engineering.co.uk

[@teamallyracing1780]

Thanks for the info how do get his contacts and where is he located

[@jonnycsuperplumb765]

Excellent info as always... cheers lads

[@artgecko2645]

I bought a recently rebuilt Pre-A+ motor and remote gearbox that has a straight-cut, 17-tooth pinion installed, but no crown wheel, diff, output shafts, etc. If I bought MED's 3.47 straight-cut pinion and crown wheel set, which I believe is a 17-tooth pinion and a 59-tooth crown wheel, can I be assured the crown wheel will mate up with my existing pinion?

[@MEDEngineeringTechVideos]

If you buy the set it comes with a new pinion. We would not advise to mix and match CWPs.

[@fitzysminis]

What about semi helical? What’s the benefit of those?

[@keulek]

Great Video as always. Do you have any figures on how much power will be "gained" at the wells step by step when adding straight cut parts on the same engine spec. Would probably be a great video as well! Ps: when are the cross pin diffs back in stock? :D

[@jonathandutoit2213]

Hi good day thanks for awesome video.I have a 1290 mini engine with compression ratio of 10:1.1 with 12g290 2 stage ported head and a 286 cam.The final drive is 4:1 ratio.My son of 12 years old races with the mini on clay oval track.10 inch tyres he only reaches top end at the end of straight.should I lower cam or diff ratio.

[@MEDEngineeringTechVideos]

Hi Jonathan, that sounds ideal if the engine is reaching peak rpm at the end of the straight?

[@Rustin-wy6yf]

I’ve got a pre a+ 1098. It’s currently at the machine shop for a 40 though overbore and I will be replacing the 202 head for a 295. I plan to occasionally use it on the motorway but mostly in the city. Would it make sense for me to upgrade the final drive from 4.1:1 to 3.7:1? Thanks in advance.

[@FHPTOM]

Newbie question. Have a Salisbury LSD in my car now with a straight cut remote gearbox. Looking at going to stock open differential for street drive ability. Have access to one with helical cut gears and wondering will it work with straight cut gearbox.

[@artgecko2645]

FHPTom, if your gearbox has a straight-cut pinion, it won't mate up with a helical-cut crown wheel.

[@ronnieg6358]

Very interesting. I am not into racing minis, but I have a mini moke (AMC Cub) with a standard 998 engine and 13" wheels. Consequently it is very high geared. I am considering changing the final drive and fitting a limited slip diff, not for performance but for improved off road traction. What would you recommend?

[@MEDEngineeringTechVideos]

Which final drive do you have at the moment Ronnie?

[@ronnieg6358]

@@MEDEngineeringTechVideos I intend to measure it soon but It's much too high at present. (I'll jack up one side and turn the wheel in top gear with the plugs removed with the diff doubling the effective turns.)

[@MEDEngineeringTechVideos]

@@ronnieg6358 OK. We'd probably look around the 3.7 mark and one of our new helical gear LSDs. That would be superb.

[@ronnieg6358]

@@MEDEngineeringTechVideos Thanks. So 4+ would be too slow? The advantage of the helical gear would be less noise?

[@MEDEngineeringTechVideos]

@@ronnieg6358 It depends what you have at the moment. Shorter than 4:1 and you will begin to loose any cruising comfort for road use. Helical gear is the name we give our fast road differential - if you see the end of this video there's some more information: kzbin.info/www/bejne/fqGti3qNnq2Lgbc

[@p51mustang7]

I’ve got a 998 A+ mini city e apparently I have a 3.1 fd but I can only get 70mph at 8500 rpm as u can imagine my head gasket bill is getting expensive what could bee the issue ?

[@MEDEngineeringTechVideos]

Are you certain your rev gauge is working correctly? We don't take even the most developed full race motors to such a high rpm.

[@p51mustang7]

MED Race Technologies how can I test to see if it’s working correctly thank you

[@MEDEngineeringTechVideos]

A timing light/strobe will help. Or try another tacho. Something doesn't sound quite right there.

[@eduardodedios8213]

@@p51mustang7 if you have an engine that is doing 8500 rpm? You have one of a kind that’s amazing, most stock or original engines top at 4000rpm’s to give you an idea how crazy 8500 sounds