From TT Car Club of America:

"The 225 comes with a turbo timer that runs coolant through the turbo after the car has been shut down. The 180 does not have this feature so it best to let it cool down for a minute or so after heavy driving before turning it off."

 

after heavy driving is the key answer and modern turbos are water and oil cooled not like the old days

 

well...this is true but the purpose of the turbo timer is to let the oil cool down so it doesnt cook in the lines and on the bearing(s)

 

First of all, an AFC (Air Flow Converter) does not measure AFR (air fuel ratio). I don't know where this misconception came from. It is simply a piggyback that does exactly what its name says, intercepts the MAS signal and converts the voltage signal that the ECU will see "tricking it" into adding more or less fuel. The only real way to read AFR accurately is with a wideband o2 sensor (0-5V signal) and gauge OR something like an LM-1 mounted downstream in an exhaust that has no cat as the cat distorts the lambda reading.

Also, the 225 continues to run coolant through the center section of the turbo after the ignition is killed. This coolant keep the oil from coking inside and causing premature bearing failure. A turo timer isn't going to hurt any turbo car as it is purely beneficial, but sometimes unnecessary. As avant80@2.6 pointed out, you really only need to let the car sit for a few minutes after heavy driving. In my old Eclipse I used to run an HKS Type1 which had an auto setting that calculated cooldown time based on rpm through the drive. The Apexi is a good unit too and I plan on running it in the TT. You should be able to wire it up though so that the keyless entry still works. I wouldn't waste the time hooking up the AFR setting on the turbo timer because 1) it probably isn't that accurate 2)it is a narrowband reading(0-1V) which should not be trusted for tuning and 3) you would need to make sure you wire it to the upstream o2 sensor and not the downstream sensor, all of which could be located at the ECU. Hope this info helps.

 

yes i know what a freakin AFC does if you look at the first post i was trying to convince true_ piony to get the turbo timer(apexi) b/c its pretty good except some of the features don't work unless you change some wiring around! the TT's electrical system is WAY differnt than your ordaniary Honda civic or toyota Supra!

 

pretty sure all TT's have the after run pump. sit in your car for a second after you shut it off, and you should be able to hear oil trickling, kinda sounds like its coming from behind the glovebox.