Welded differentials

[Ron Earp]

Seems to be they'd have to be slower for reasons as Steve stated. Of course it could be the increased traction helps the corner drive so much that it negates the higher driveline losses.

I just put a welded diff in my car for the Daytona race. It isn't that I wanted a welded in the car, just that the 3.56 gear I wanted to put in the car is coupled with a welded setup spare diff. Easiest to simply bolt the whole thing in place. I imagine it'll be a pushy car, hope it doesn't have any life threatening handling characteristics.

R

[seckerich]

I had the same comments from a certain Swift driver in his production car. Top runoffs driver as well. Built him a good limited slip and he noticed the difference immediatly. You can set the car up so you are faster, but there is always a little more left on the table. A comfortable, confident driver is fast despite the setup. Personal feel.

[Ron Earp]

Steve, got any quick last minute tips for setting up a Z car with a welded that generally doesn't wear a welded? I imagine softening the front sway a bit would be a good first step?

R

[betamotorsports]

Here on the west coast most of the ITS guys who ran S30s used a welded diff. The setup differences from a LSD rear diff are:

300F / 325 or 350R springs
1" front ARB, 3/4" or 5/8" rear ARB.
Front toe: 1/8 to 3/16" out.
Rear toe: 1/8" in.

[JeffYoung]

John, thanks. I'm still trying to get Ron to buy your Koni 8611 kit....eventually I will win out.

Right now he has 600 lb front springs and 300 rear, not sure about bars (no rear bar I think) and toe.

I smell massive push. Your thoughts?

[shwah]

I had the same comments from a certain Swift driver in his production car. Top runoffs driver as well. Built him a good limited slip and he noticed the difference immediatly. You can set the car up so you are faster, but there is always a little more left on the table. A comfortable, confident driver is fast despite the setup. Personal feel.

Did Woody have a spool or a diff in the podium/rain race?
Chuck runs welded in the Rabbit, and as mentioned Chris does as well. I thought that the whole G podium that year was fwd welded - maybe I was wrong.

Chuck tried some 'real' diffs back in the ITA days with disappointing results.

[betamotorsports]

Far be it for me to criticize someone's setup, but 600 lb. in front springs on an ITS S30 is at least 200 lb. in. higher then I've heard anyone run, and that includes the Chet Whittle/Keith Thomas ARRC winning car. I do know of a few guys down in Australia running 600/450 on their S30s but they have a lot of chassis reinforcement done and are definitely beyond IT levels of prep.

Maybe it works and more power to the folks that make it work. Its always better to try something different with the chance that you'll make your car faster then to copy and know your car will be just as fast.

[Ron Earp]

425lb F / 350lb R.

I think 600F would be far beyond the stiffness of the chassis. 425-450 is pushing it I bet.

[JeffYoung]

Not to disclose any of your secrets but I thought you were higher than 425?

I tell people about the 600s in the front of my car and they say the same thing...won't work. Seems to though.

[OTLimit]

Chuck tried some 'real' diffs back in the ITA days with disappointing results.

Back in the day, both Chris and Chuck bought Quaiffes; after doing what everyone said and trying to make them work, and draining and dumping lots of sparkly gear lube, they finally gave up and went with the welded diffs. It was an expensive lesson.

I do believe that Chris managed to break some type of lsd, but can't remember which one right now. If he believed that the welded diff was causing him to lose important races, I'm pretty sure that I would have paid for something else by now.

[shwah]

All this said - we are looking at running a Kazz lsd at the 25 hour, in an effort to make the setup as easy on the Jetta parts as possible. In that case Chuck, Chris and I should be able to give some comparison feedback between the two setups (of course need to finish building the car first...)

[racer_tim]

I've only lost 1 CV joint while running the welded diff for 8 years now. I change out the entire 1/2 shaft assembly, including CV's and hubs every year as "standard" maintenance.

[Ron Earp]

Not to disclose any of your secrets but I thought you were higher than 425?

I tell people about the 600s in the front of my car and they say the same thing...won't work. Seems to though.

450 it says on the spring, looked tonight. My bad. Not any secrets around here - if folks like to go as slow as I do....

Seriously, the 450s feel great in the car and were the single best thing done to the car, replacing the 325s that were in it. Now working on that other stuff like struts....

R

[racer_tim]

HEY, this is the VW forum. We don't do RWD in this section. All you Datsun/ Nissan guys, get over to your own forum.

hehehe

[veeman]

I just got the chance this weekend to try a welded diff in the rabbit. I read a lot of info here and talked to a few other racers before installing it, but I'm glad I did.

I was initially nervous about the stories I'd heard about the "push" and adapting driving styles based on the locked diff, but it really wasn't that bad. After a few laps, I was used to the "get on the gas" through the corner thing and was loving the grip.

I need to do more work on the suspension to dial in some more rotation, but that'll come soon.

I've driven rabbits with the open diff, limited slip (Quaife) and now the welded diff and my vote is with the welded setup. The only thing I don't really like is having to muscle the thing around in the paddock / false grid.

[racer_tim]

Yes, it does require "Popeye" type bicepts to make 90 degree turns in the paddock, but you need to learn to setup your paddock space so you can just "drive in, drive out" without making those really slow 90 degree turns.

[loopracing]

We've used welded for the last 13 years with good results. As far as the "popeye" arms, I'd suggest a larger steering wheel. A 14" should do the trick. Poor man's power steering.

[loopracing]

If you want to keep CV's then don't make 90 degree turns in the paddock either.
If anyone needs one welded, email me, I can turn it around pretty fast if you want.

[chewy8000]

I just started racing this year and all I've driven is a welded diff. I have no idea what anything else is like... Any of you other rabbit guys running the front sway with the welded setup? I have been told by many people not to, but one of the DC region rabbit zen masters swears you should keep it on. Thoughts?

[racer_tim]

I run a front and rear bar with my welded setup. I did the same with an open diff. The major difference, is that I don't loose traction on the right hander turns. With the open diff, I used to hear the "chirping" of the inside wheel trying to get traction.

With the welded diff, you get traction on both front wheels all the time. Keep in mind with a welded diff, that the inside tire travels the shortest distance, so it feels like it's "pulling from the inside".