Welded Differentials?

[majik16106]

I see a lot of race cars with welded diffs, i thought that was only a good idea for drag cars, but i have seen some RR cars with welded diffs recently, seems to me that was a real bad thing because one wheel would be moving at a different speed than the other in a turn? so why would someone be doing this? wouldnt a good ole r20o lsd work much better?

[johnc]

Cost is the big reason. For road racing you normally need at least two sets of gearing if you race at different tracks. At higher track speeds the lack of rear differentiation isn't an issue and can be adjusted for with springs, anti-roll bars, and alignment.

[majik16106]

but iw as under the impression that welding the diff would cause the inside tire to drag making it almost impossible to turn ilke a drag car would be?

[johnc]

but iw as under the impression that welding the diff would cause the inside tire to drag making it almost impossible to turn ilke a drag car would be?

 

Not true. The inside tire does drag a little bit, but at track and autocorss speeds that drag is very minor compared the friction induced by the tire's slip angles under load. In slower corners the locked rear tends to induce understeer but that can be easily overcome with trail braking and throttle application.

[majik16106]

This is why i listed you in my "thank you hybridz" thread. Ok, with that being said, if i wanted a diff with say a 4.11 so i could do burnouts and slide around and yadda yadda, one to change out when im gonna be a goofball, this would be a not so bad idea? because the 3.54 is what on the car during regular driving.

[johnc]

Yup. Just find the 4.11 R180 diff somewhere and take it to a weldor to get locked up. When welding the diff the weldor needs to make sure the side gears are square to the diff case or the diff will be out of balance and there will be a vibration.