I was noodling about this on my way to work this morning and I was thinking that it'd be nice to be able to lock/unlock the diffs exiting/entering corners at a rallycross. The current switch location is hard to find while turning, bouncing, sliding, etc.

I haven't taken a look at the bentley wiring diagrams but I don't know why this wouldn't be possible.

 

A certain Scott Justusson, who hangs aorund the audifans.com quattro list, has done just that. His purpose was for enhanced performance at the Steamboat Springs winter driving school, snow driving course. I believe his email is QshipQ@aol.com.
The controls are entirely vacuum, with an electrical connector for the indicator light. I have heard of several folks who have moved the panel to various locations, most frequently to the bin forward of the driver's knee. Just some vacuum tubing, perhaps extend the indicator wiring (if you even bother) and you're on your way.

 

ive had this diff lock thing staring at me for a few months that ive owned the car now, i know what it does and how it works but i dont know exactly when id use it aside from getting myself out of mud holes and to get moving on ice. is this a performance feature? is it ok to drive fast with it on? im curious how useful this thing really is..

 

Here's the scoop.

The '0' position is an open diff, which allows the front and rear wheels to turn at different speeds, similar to the rear axle on a rear wheel drive car. Engine output is sent here first, then to the 4 wheels. Each wheel gets 25% of available torque, all the time. Once a wheel loses traction, that's it...it spins. This setting is perfect for rain, so don't use the '1' position for that.

The 1 setting locks your center diff, as shown by the green light. This setting locks the front to the back, basically making your car a 2-wheel drive. For example, if the RR and RF wheel are on ice, they will spin and you will get nowhere. Use this ONLY for slick conditions, like snow, ice, gravel, dirt etc. Do NOT try to use it on pavement, wet or dry, especially in tight turns. It will damage your drivetrain. If your tires are different sizes, change them to all the same size NOW before needing to lock your center diff. If your tires are different diameters, you will be all over the road.

Lastly, the 2 position locks both rear tires together. This is a highly unusual thing for a car to have, as many 4x4 drivers put these on their trucks for added traction on steep hills when rock crawling. I really don't know why Audi decided to use the rear diff locker, but it will make your car climb stuff you couldn't walk up, especially with snow tires. Only use this if that hill coming up is near vertical, or you are stuck. Ironically, in some circumstances, having the rear locked will actually hinder your progress as the rear end will tend to 'walk out' on you sideways, so use caution with this setting.

2 years ago we got 11" of snow here near DC. Theres a great switchback drive up a hill near where I live, so out I went. I don't know how many SUV's I saw stuck in their driveways or in ditches...including this Toyota 4x4 pickup with monster tires spinning one tire madly in the air (again, this is why a rear or front locker comes in handy).

Have fun, and I highly recommend snow tires if you can...on all 4 wheels.

 

thanks!

 

Stiff knockers?