5 replies to this topic

[cardboard]

im new to gearbox's and wondered what in plain language this means. its fitted to a 1380

"gearbox ratio60mph@3000rpm=2.95:1 (1.1dropgear)"

thanks

[fikus01]

at 60mph your rev counter will be showing 3000rpm.

diff ratios are hard to explain to sum1 new to them, not knowing your backround u may not understand at all unless u see pictures.

have a look on how things work . com, im sure there is a website like that, just search it and it'll shhow u.

[cardboard]

thanks is this a good gearbox or not really or just suitable

[Retro_10s]

Not bad from 60mph at 3000rpm, think it's motorway cruiser basically.

[TOMMO0302]

In basic terms (which is lucky as i couldn't explain it any other way) your engine or diff or whatever will turn 2.95 times for every one turn of the wheel. I think standard 12" wheeled minis are generally a 3.44:1 diff but you can get higher than that and lower than yours at 2.76:1...

So your acceleration will suffer, but your top speed will be greater. So whether that is any good or not depends on the type of driving you are to be doing....if its mainly motorway miles then it will be good, as you can sit at 70 without the engine screaming at silly revs....however, if you never go over 60 and you like planting your foot off the lights etc then it will be hampering you. Oh, and those figures only refer to the diff, not the gearbox, you could change the diff and keep the gearbox..

...some of the above might be slightly innacurate but should give you the gist of it

[TimS]

Yeah you're right retro. The final drive will give you good motorway cruising speeds and economy. If the engine has the power it will be able to achieve high speeds but to counter this the acceleration will be a little sluggish. The 1:1 drop gears are the ratio between the engine and gear box. Basically for every rotation of the crank the gear box input shaft will turn once. 1:1 is the STD ratio.

Edited by Flappyplasticbits, 16 January 2007 - 11:42 AM.