I am currently running an elite clutch plate diff, with pretty steep ramp angles 80/90, this was suggested from Elite and worked well with my 300 bhp duratec , but I'm interested in what to run in the BEC? What's the general consensous? Regards

are you using the elite diff for definate?
the ford 7" diff with zf lsd 3.14 ratio and de dion is what most go for i think! and with good results

45/90 is what i have in my tranx, seems to work well. preload is light as well, about 35lbft.

the 80 sounds a strange one to be using from my understanding of how they work.

I rebuilt the diff a few months back after looking into various manafacturers, Titan being the most favoured by Caterham/ Marketing , Tranx and Elite, i had an Elite IL200 Box and thought i'd match them up. Agreed the ramp angles seemed steep and i was advised of something like 30/90 or around this area.........but in another breath i was advised that the manafacturer would know his product better than anyone else hence i went with the 80/90 and had no dramas.

My real thoughts are behind how the weight ( in all its guises-weight transffer-rear end grip...) engine braking or the effects of the matching of rear wheel speed to engine speed on downshift, lower power etc being much different from the heavier higher hp car compared to a BEC...........i might have answered my own question though RE manafacturer, ill give them a bell and see what theyre take on it is.....although as mentioned this might be a simple pre-load change

As for ratios, i havent worked out what tyres im going to use, or what engine speed shall be used yet.

Thanks for the replies

This is a good post from a few years back explaining ramp angles

http://www.turbosport.co.uk/showthread.php?t=145204

Thanks, I get the ramp angle side of it all, I was wondering about real world experience. With a 80/90 for the caterham a of of people poo poo,d it as it wasn't a caterham standard spec, but turned out to be fine, so the proof was in the pudding. Cheers for all the replies.

you say it was fine but have you tried a more aggressive diff? it may be even better. then again it may not be.

with my 45/90 it did bring a touch of understeer to the car in certain corners. more than makes up for it the rest of the time though.

maybe a 60/90 is the way to go, not sure if they make them though.

True! i swapped from an ATB to a clutch plate. The car did understeer on throttle where as i would have preffered a little more oversteer with stiffening the rear ARB/ spring rate, but we think we could have run a little less camber and got more contact patch, the car was performing so we didnt really faff around with it, testing is expensive and race days were guaranteed decent lap times.