I agree with Phunkdoktaspok.

My father has been using 'CIG' diffs for nearly 35 years in his racing cars - both circuit & dirt.

The only things he ever welded was the sun gears - just a single, clean good sized weld. He believed that this not only gave it adequate strength but the single weld to both sides of the sungears allowed for a tiny bit of flex.

The other things he always said was "learn to drive properly. If you simply plant your foot from nothing to flatout what do you expect".

I have always had friend that paid the big coin for gearboxes, synchros & diffs but they always blew them apart - me, i was just as quick & have never done a diff or box in my life.

i guess it's the lack of h150 style locking diffs.

if i were making a datto for doing tricks in a parking lot, hehe the more locked the better, helps the rear end keep it's velocity up so 180's are super easy lol - maybe get some 280zx struts too, put the front wheels a little wider...

i'm guessing that's not the handling dynamics you want lol...

i had a car once that was a white nuckle ride and long commutes got old. only being able to go 60mph in the rain wasn't much fun either.

Ok someone feel free to convince me otherwise but the only reason to weld up a diff vs LSD for our low powered cars is price.
And as mentioned if you drive in the rain regular good luck on tight & slippery curves. We had a whole crew of guys here with welded diffs on thier RX3's and 7's and whenever we had races where it rained most off them put it off the road with understeer..........a few brave souls snap spun it off to the inside (with little rain our tarmac is like ice when it rains)

Tom

I have recently had my diff welded - in saying that though, the car is for race use only.

The reason I went for the CIG option is because it was far cheaper for me to weld up 2 spare diffs (just in case) than what it was to buy or 3 LSD's.

The reason I went for a locked diff is because event with the car only producing 190hp (still to be tuned) i could simply not get the power to the ground due to wheel spin - the locked diff took care of this.

if you have that much HP, maybe it's time to invest in a traction control system, LSD for one, maybe bring on the power a little more gently, or is it a tire thing?

basically lots of high powered cars don't suffer loss of traction constantly, unless that's what you're trying to do.

all the locked diff is doing is letting both wheels spin at hte same speed till you get traction.

To be honest I think it was a combination of a few things such as car set up, suspension etc (including the driver).

I am currently running on slicks so the tyres are good - its just a matter of being a little gentler on the throttle but the locked diff is nice - kind of a point & shoot application now.

the breaking of traction really only happens when the car is unsettled or when it becomes 'light' through off camber corners -the diff just enables both wheels to spin as one providing constant drive even when one starts to lift off the ground.

It's all fun.

Or you could do it my grandfathers way ( "if it was good enought for xy gtho's its good enough for your little datsun") he used to spanner on george reids race cars for the hardie feroddo stuff at bathurst.
brace yourselves... a packet of welding rods.
it works but i wouldnt recomend it.
also you need to look at the handling of the car as a result the car will push or understeer in the front and randomly snap sideways under power. if you are doing it for racing its the most fun you can have but be ware if your doing a circuit race the diff will come under a lot of stress and axles will break.
also i think in australia welded diffs are illegal for street use but im not sure