Welded diff

My latest acquisition has a welded diff. How bad will this be on an autocross course?

What car, class and tires?

93 240sx Will be in a modified class. Would it be better to replace it with LSD?

It will push big time. If is is more or less stock you will not have enough power to really overcome that.

It will push until you fling it hard and make it oversteer. There will be no in-between with a welded diff in that car. Definitely replace it with an LSD.

An open diff would probably be better than a welded one.

Unless you're going straight, welded diffs on asphalt are not good. Get rid of it asap.

Drift-tastic. Big show, big fun and lousy times.

I'd run a few laps and see before going to the trouble of swapping in out. It might be better than you think...or might be worse

I've driven a welded diff car on an autocross course, it wasn't dreadful and it was a lot of fun but it wasn't really competitive. It's a good setup for drifting but not autocross.

The owner of the car usually ends up mid-pack or lower competing against cars of roughly similar performance.

It's the sidewaystastic red and black Datsun with a cage in these videos:

https://www.youtube.com/watch?v=qzwPkC9TD34

https://www.youtube.com/watch?v=mvJF9hWNWQw

GameboyRMH wrote: Drift-tastic. Big show, big fun and lousy times.

^this

Gearheadotaku wrote:

GameboyRMH wrote: Drift-tastic. Big show, big fun and lousy times.

^this

Sounds fun. I have a stock one I think. I'll be scrapping the body as soon as I get a new one.

Livable on a road course, not so good for autocross

oldtin wrote: Livable on a road course, not so good for autocross

especially in the rain

I'm not so sure about the "suck" part. Properly set up a welded diff can be fast and fun. I autocrossed a RWD car with a modified 4cyl with a welded diff and it was fast! We ran a Ford 8 inch with a 4.63 rear gear with enough power to break the rear tires loose when needed and we ran slicks!

I think the difference is that on a car with rear IRS a welded diff may not work that well. On a soild rear car it can!

Knew a couple that ran a 510 in GT4 that ran a welded diff. They complained constantly about lack of turn in and snap oversteer, their driving instructor kept trying to help them work around this, only he didn't know that the diff was welded at the time. Once he found out that it was welded, he had them replace it with an open diff and the car consistently went faster around the track and the driver's were happier since the car was easier to drive. They've since put a proper limited slip in to cure the corner exit wheel spin and the car is faster to drive.

Personally? I'd pull it and see it to a Dorifto kid and take your Holiday money (or tax return money) and buy a decent limited slip. If you want to try, go ahead, just make sure you know how to left-foot brake/throttle steer to keep the rear end moving around or you'll understeer quite a bit until the rear tires break loose.