gearbox problem... doh!

[baz-r]

Originally Posted by Eternal

Thanks just seen your v8 height thread. dude that engine is massive. Im really worried about the dif to be honest. its going to be a nightmare to mount. =( the skyline dif is a 4.1 ratio do you think i can get away with a 3.9 sierra one instead or maby a 7.5inch cossy one? (RB25DET - twin-cam turbo (T3 Turbo) ~245 to 250 hp and 319 N·m) ~wiki) my one will be old so not that much power. it would save sooooooooooooooo much trouble,

Also can someone measure how high the center of the dif shaft center is from the table top? just so i can get the gearbox inline.

Thanks again all

Edit found out my gearbox ratios i dont have a clue at all about this kinda stuff all those cogs are confusing. So can anyone who knows whats what, advise me to the best dif for this 'RP71C #2', the ratios are 3.32, 1.9, 1.31, 1.0 and .838.

http://cgi.ebay.co.uk/SIERRA-SCORPIO-GRANADA-3-91-7-5-INCH-REAR-DIFF-KITCAR-/390211222449?cmd=ViewItem&pt=UK_CarsParts_Vehicles _CarParts_SM&hash=item5ada66bbb1 Found that but duno how hard it would be to fit as its a bit wider. i presume the shafts will need to be modded/shortened

the ratios are for each gear so (1st) 3.32 means for every one prop rev there is 3.32 crank revs.
1.0 is one in one out (like most 4ths are)
and .838 is a over drive where the prop spins faster so every .838 crank rev you get 1 at the prop
take this into account with your dif ratio and your rear tyre dia and you can work out speeds to revs
engine revs/gear ratio= prop revs, prop revs/ diff ratio = wheel revs and times this by wheel dia to get road speed
simples