A hot car needs a limited-slip differential. Sadly, one isn’t commercially available for our Bugeye. Thankfully, we have a machinist friend, Steve Eckerich, who makes them.
The case is machined to accept the clutch packs, he explains. The gears are also machined, while a pressure assembly is installed between them to add pre-load.
The other options (both of which I have used) are welded diff and commercially available LSDs like the Quaife.
A locker sucks in the rain, in tight corners and pushing the car around the pits (you quickly run out of volunteers) The Quaife is quite good, although not a limited slip in the sense often used in regard to this sort of diff - if you lift a rear wheel off the ground you do lose power to the other.
FWIW, I have run with a Quaife in a live axle car (MGA) and with a stock open diff in a slightly lighter car with the same engine - TVR - (I mean the identical engine taken out of one car and put into the other). Had similar times, which wouldn't have been the case with a live axle and open diff.
On tracks with turns that result in significant unweighting of one wheel, the LSD can result in a second or two off your time (which - ask any racer - is a lot!)
If you have a well balanced car, corner weights and suspension is set-up correctly, the the quaife is superior IMHO....
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In reply to wspohn :
This was a low buck way of solving this problem. You cannot run a locked rear on the street.
Tim Suddard said:In reply to wspohn :
This was a low buck way of solving this problem. You cannot run a locked rear on the street.
Well you can, but it sure is tedious and given that the wheels aren't mostly sliding like they are on the track, you are likely to have problems like broken axle shafts.
A couple of idiots I knew welded their spiders and ran their (American) cars on the street that way. Tedious to drive and a bag of snakes in the rain. So I'd say that while it is possible to run a welded locker on the street, you'd have to be an idiot to do it (that description covers the two guys I refered to nicely)
In reply to wspohn :
I upgraded to the later, stronger axles that hopefully solve that problem.
I use a Quaif in my one Cortina.And yes if you start unloading one rar wheel it reverts to an open diff.The cure...for me... was to soften rear suspension so the body would roll more and keep both rears on the ground.Works great now.
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