23 replies to this topic

[TURBO-TOM]

can somebody help me

I dont know much about gearboxes and want to put straight cut drop gear in my gearbox, can i put straight cut drop gear in a standard box or will i have to get a full straight cut gear set?

cheers tom

[Mini-Mad-Craig]

You can run drops on their own. What power are you running? I doubt theres any point.

[mini_mad69]

Most people want them just for the sound, yeah you can chuck in a set of straight cut drops no worries.

[LiamB]

Looks like I came into this thread at an awkward moment..

Anyway, you will get annoyed at the sound soon enough.

[mini_mad69]

k









LMFAO poor OP!!!!

Yes slap some straight cut drops in your mini mate, you will gain a little less side loading and a slightly improved resistance in power transfer.

[oltonlad]

are you running a 998/1098 or a 1275 as the drop gears are different for a small bore engine.

[Artful Dodger]

i would get a bit of a headache if it was in a daily driver, but if not straight cuts are cool!!! just a replacement job, not special parts as such.

just make sure to get the tolerances right etc etc. as these gears can become ineffective unless set up correctly:P

but the straight cut box with the gear cluster is AWSOME:P cant beat the sound of a straight cut mini

[oltonlad]

i agree on checking the tolerances but its not as critical on straight cut drops as it is on helical drops as they dont work against each other like helical gears do.

[AndyMiniMad.]

Drop gears dont go inside the gearbox..they go in the transfer housing..they transfer the drive from the crank down to the gearbox which as we all know is below the engine, hence the term "drop gears" here are my noisy straight cut roller drops from MED.



The gears inside the gearbox are seperate things altogether..but can also be straight cut if desired..These ones are not straight cut..

Edited by AndyMiniMad., 16 March 2012 - 10:14 PM.

[TURBO-TOM]

hi thanks everyone that helps a lot, and im hopefully going to be running at about 160bhp

[oltonlad]

hi thanks everyone that helps a lot, and im hopefully going to be running at about 160bhp

you will need a full straight cut box if you are running that ammount of power, i wouldn't fancy putting 160bhp through a helical box.

[Beej123]

hi thanks everyone that helps a lot, and im hopefully going to be running at about 160bhp

you will need a full straight cut box if you are running that ammount of power, i wouldn't fancy putting 160bhp through a helical box.

Totally agree, the gearbox WAS over-engineered but remember, it was designed for less than 40BHP! 160 is a lot of power to throw through the standard helical box.

[george91]

Yes you will need a straight cut gearbox with that power, don't worry so much about the transfer gears unless you really want them. The minispares clubman gearkit is popular. helical transfer gears have been proven on cars over 200bhp so not necessary unless you want them, its the gearbox that is the weak link, cross pin diff will also be necessary if you haven't got one yet.

http://www.minispare...id=36035&title=

[Pauly]

I would seriously consider S/C drops. I beleive roberts car on TM ran a full helcial box with s/c drops and it seemed to hold up well, for quite a while. The drops will reduce side loading and transmission losses. You can get different ratio of drops. 1:1 being the most popular, A 24/24 (primary and input) will not be too noisy. Mine are 22/22 and are deafing.

I would say a helical box could take it with s/c drops, but everything would have to be in A1 condition. Helical gearboxes are getting old and tried now so its less likely for them to survive the power being put through them than they would of done 5/10 years ago.

Edited by Pauly, 17 March 2012 - 05:50 PM.

[george91]

Pauly it was Roberts car i was talking about, and he has it the other way around, the gearbox is straight cut, but he is using standard helical drop gears, with as you know well over 200bhp, 240 IIRC from one of the rolling road shoot outs.

For peace of mind i would be using a s/c box.

Edited by george91, 18 March 2012 - 11:51 PM.