zzzing

TPMS? detects differences between, or just low vs high? anyone agree w/2psi less rear for track day?

bhvrdr

I actually go up in the rear to add spring rate and attempt to weed out that disconcerting rear end sway that is in the RS4 and S4 if going off throttle mid corner. I've found upgrading the rear suspension helped to totally rid the car of this trait though.

Rule of thumb for pressures that I do is start out with a test run and see where your FRONTS are as far as tread use. Get the fronts dialed in first and foremost to be using the most tread without going over onto the walls. Use your triangle indicators for this. For these cars you want optimal front traction.

Next, either start up or down on the rears depending on what you want. For those who like to have a little break away and then snap you can go down. For those who like a stiffer progressive but sharp breakaway, I go higher. I go up 2psi to begin and one more psi at a time until I get the feel I like. Monitor your rear tread in that situation. You should be inching away from the sidewalls as you use less of the tread to gain more neutral handling. One of the R10 techs was discussing their setup on the race car with our group at sebring and he was indicating they found 1psi = to 400lb of spring rate on their cars. With our rear spring rates a bit soft, I like to go up in the rear. Plenty of folks like to go down too. Preference.

Bob W.

i'd leave the pressures as is to start, then check after the first session and adjust.

bpp

Right on Mike.

Phantom RS

TPMS does not worry about differences between tires, just absolute thresholds for each tire.

absoluteis

What are you guys using to measure tire pressure? Need a decent gauge cuz mine suk

RI A6

<ul><li><a href="http://www.tirerack.com/a.jsp?a=AR4&url=%2Faccessories%2Fairgauges%2Fairga uges_all.jsp">Tire gauges</a></li></ul>