Detroit Lockers

[gttouring]

i know Trans-Am cars use a Detroit locker in the rear end so as to avoid expense and LSD development- but what are the advantages of the detroit locker in road racing other than making it scary and hell bent on straight line acceleration?
Factory and custom LSD are available (and of the Dteroit brand as well. even a cool electric locker for the differential...)

[noise boy 2]

Do they use a locker (which is actually a lsd) or is it a spool? I thought that they used a spool, which takes the place of the spider gears and what not of the differential locking the two axles together. A detroit locker is just another type of LSD, instead of using clutches (eaton/gm) or cones (auburn) it uses a ratcheting mechanism to lock the axles together in a straight line, and unlock for cornering.

[noise boy 2]

That is a spool, here is a detroit locker:

[gttouring]

it is a locker not a spool.
thanks for the picks- and by LSD i was referring to a clutchpack, and/or viscous coupling ala Lamborghini and NIssan types. I would imagine friction material and heat sink research would be huge here..

[noise boy 2]

I agree about the friction material, the Eaton posi that I put in my car has "f-1 derived carbon clutch plates" in it to control the slip between the two axles. All I can say is that even with the designed in slippage, there still are occasions where I get a ton of wheel chirping from one or the other of the wheels when turning. Also it might as well be a spool when it is wet out, as having the back end go away on you is a real action in every corner. Robert

[gttouring]

great thanks- I have a Nismo viscous coupling limited slip, works great, but the rain thing get lots of noise and skipping at the rear.
by the way- do you just have pictures of spools and lockers in your computer?

[noise boy 2]

Nah, I went to the summit racing website and stole them from there http://www.summitracing.com

[GTV27]

Of the three cars that I regularly race, the GTR XU1 has a detroit locker, the GTV has a clutchpack LSD and the Clubman has an open diff (class rules).

Given that these are wildly differing vehicles, I can't be too sure about how much the diff is playing a part, but the XU1 (with the detroit locker) needs to be driven very positively on the throttle - big lift off on turn in and then lots of throttle to drive it through the corner. Not much finesse required. Its always cornering on the rear wheels (ie oversteer), understeer is rarely an issue and never under power (despite the legend for lockers). This makes it great fun to drive, but not necessarily the fastest.

The GTV has quite a tight diff with a fair bit of pre-load, but is a lot more sensitive to small throttle changes (the adjustments don't have to be as pronounced). It doesn't have the Hoon factor of the XU1, but is more often than not faster.

The Clubman is on another planet altogether in terms of throttle control and except for the very occasional inside rear wheel spin, is just fantastic. But of course with an LSD, it would probably be better - didn't somebody famous say that LSD makes everything better?

So in summary, the detroit is brutal, but reasonably effective. For ultimate performance, I'd say a clutch pack or viscous LSD would be better.