Welded differentials

[jcg3813]

I like to know the pros & cons of using them, what you people suggest ?.
Thank you.

[Dano77]

pros,both wheels apply power,con,both wheels subtract power...you will most likely develope a massive push until you smash the throttle enough to break the inside wheel loose,then balance becomes your best friend. You can overcome the cons with stagger but we turn left & right so weigh your option at the track. Pro,wayyyy cheaper than a quaife or detroit locker,con,still pushes. good luck.
Dan

[Weaver7]

Like Dan said it will make the car push like a stuffed pig however it will teach you how to rotate the car properly!! Had one in our first Gen RX7 only ran it for a couple of races though.

Bill Weaver
ITS RX7 #63

[Tak]

Pro's of a welded diff: Cheap. Almost as fast as a fancy diff IF the car is set up right. You'll never lock up just one rear tire...
Con's: Properly set up cars for a welded rear end will wear tires faster; they will be scary to drive over the range of high speed and low speed corners; if the welds fail, it's bad; if it's not set up right, you will get lots of understeer (as in hello wall); impossible to roll the car around in the paddock, driveway, garage etc.

For a road coarse, a car with a welded diff needs to be set up like a go-kart--that is it MUST lift the inside rear wheel when going around corners. This is typically done with significant rear anti-sway bar. Suspension springs must then be selected that will result in a somewhat balanced car when it's on 3 wheels. A roll cage structure that really stiffens the chassis will help tremendously. It will eat rear tires (because only one is on the ground while going around corners). Good damping will also help. If you are not afraid of oversteer, it can be fast. Note that extra care is required in esses and chicanes--the car will require more time to transition from one direction to the other than a car with all 4 wheels on the ground (the suspension physically moves more and transfers more weight around in a welded diff car).

FWIW, many many moons ago I got to play with a formula SAE car that could run either a Torsen or a spool. Properly set up, the spool was as fast as the torsen around an auto-cross type track. Around a faster track, it had too much oversteer with a spool. Very comfortable with the Torsen though.

Hope that helps,

Tak
#29 ITA SFR SCCA

[Tak]

Whoops, must qualify my previous response--all that applies to a rear wheel drive car. I haven't got the foggiest about setting up a front driver. I expect you still need to get the inside drive wheel off the ground, but have no experience there.

Tak

[RX3]

I have run a welded differentials for many years on a rear wheel drive car and like it.

[shwah]

With this post being in the VW/Audi forum, I will guess it is in reference to fwd.

They work great, cost less than 'real' differentials, but do require/allow some different setup and driver habits.

Understeer is not the problem you might assume. Just get your foot on the loud pedal and it will go where you point it.

When I started using one, I got myself ready for the higher driver effort/concentration that would surely be required to tame a cantankerous fwd locker. In fact it is much easier to handle than you think - except in the paddock.

[Drew Aldred]

+1 to what Chris said above. I've driven both on a VW and prefer the welded diff. Not as much push as some people will tell you. Point it where you want to go, stomp on the gas and hold on, because you are going right NOW !!!

Pushing it around in the paddock is a pain with the welded, be careful not to backup while driving and make too sharp of a turn - easy to snap an inner CV joint.

[chewy8000]

I run a welded diff and love it. It does push like crazy, but you learn to control it.

Pro's:
1 - you can brake incredibly late and deep.
2 - With good rain tires you can win races.

Con's:
1 - Pain in the arse to move around in the paddock.
2 - plan on eating up a few CV joints over the season.
3 - If you early apex a turn don't lift! Stay on the throttle or you'll end up in the wall.

Just my experience in the rabbit GTI.