Porsche Enthusiasts Club Forum

I was reading that there is an adjustment under the car for the automatic transmission, and it affects the shift speed/quality? Anybody know anything about this?
It's called a "transmission vacuum modulator" according to the article I read, and is connected to the vacuum system. Apparently there's a cap which you remove, and a small handle which you turn clockwise to "make the shifts firmer and later" and anticlockwise to "make the shifts earlier and softer".

That's correct info you've been given Lightning.

I've never wanted to adjust mine, but the procedure is documented on Nichol's Tips:

"Under the rear of the car, you will find the transmission. Hopefully you already knew this. Just kidding. Anyway, on the driver's side up near the linkage is a round part with about a dime sized black cover on the
middle. On my car the round part is green and the dime sized cover on it is black. This is the vacuum regulator which adjusts firmness of the shifts based on vacuum. You will see a vacuum line running into the top of the regulator. The quick and dirty way to do the adjustment is to pull this line off. This will give you full firmness on the shifts. That’s what I did and it feels great! In my opinion, it’s not much harsher but much crisper. Make sure you drive a bit until the tranny is warm to judge it because its somewhat harsher while its cold. Also MAKE SURE YOU PLUG THE VACUUM LINE WITH SOMETHING! You don't want it sucking up dirt. I just used a screw that fit firmly.

If you don't want full firm, you can adjust for something in between. Pull that little dime sized cover off and there should be a little handle that pops out. If you turn the handle clockwise, you get firmer. Counterclockwise, you guessed it - softer. I think that’s correct; I could be backwards as I said I didn't bother to do this. I personally think it feels great on full firm. Hope you all can use this."

Not strictly about the original thread, but I've read that an owner of an S4 has had his auto box adjusted by Paul Anderson so that it moves off in 1st gear rather than the default 2nd. Does this apply to S2 autos as well? Do any other owners know much about this or can recommend having it done?