im trying to work out the diff ratio on my seirra diff how do i find this out ? plus if im running 195/45/16 tyres im wondering what diff ratio i should really have

im more interested in 0-60 times than flat out speed.

thanks
simon

Mark output flange - mark input flange.

Turn output flange once and count how many times the input shaft turns.

ie if one turn of output make 3.5'ish turns of the input shaft - chances are it's a 3.62:1

Get it?

if i were you, id pick a simple 3.62 LSD. I dont feel happy above above 85 anyway, i never trust the bodywork not to blow off! Just as well really, as i lost a cyclewing last night

Yeah, but he's building an MK Joel

Pat...

for best acceleration, use the highest numbered diff (eg 3.92:1). This will give you the most acceleration in each gear but the lowest top speed in each gear. Fine if all you do is sprinting but it will become annoying on the road. I have a 3.62 diff amd 195/50/15 wheels and I think that this should be fine. 50 in 1st, 70 in 2nd, 90 in 3rd, 100 in 4th, 110 in 5th 120 in 6th at the red line, give or take.

Some prefer 0-60 in 1st for best boast factor or for drivability as the gear changes will be further apart. For this you'll need a 3.14 diff and big wheels probably. This will give the least acceleration in each gear but will give a bigger top speed.

hellfire
input & output r we talking
diff flange (prop end) & hub flange

thanks
simon

yes, he is

Be sure the two outputs turn together.