Target hot pressure for Direzza Z2?

Saw the thread about the Rivals this morning and that reminded me. I have my first track weekend coming up with the new Z2s. Does anyone have any guidance on what the proper target hot tire pressures for track use are for these?

Thanks!

My autocross experience (I know, hear me out) is that the pressures that give the best temps are very wheel width dependent. A narrower wheel will like a lower pressure for a given tire width. I'm not sure if that helps at all.

Not sure about the Z2's, but my "originals" seem to like high 30's hot with a couple psi more in the front than rear. Last event I used 38 psi front, 36 rear on my Miata. This was for an autocross and it was giving me a pretty much perfect "scrub line" to the arrow indicator on the edge of the tire. Track day vs autocross, Miata vs your car, wheel width, Z1 vs Z2's might make all of that irrelevant to you.

On my AE92 with Z1SS I run 42 front 27.5 rear cold pressures (with 195/50/15s) for autocross. Which is in proportion with the weight balance of the car. GRM did some tests running the same size on a Civic of similar weight and also found that higher pressures on the front were better up to 42psi.

Hrm, I'm going to have to get used to running higher pressures in these things I guess. I always ran my old RT615s at 30F/28R hot psi. The Z2s are 245/40/17 F, 255/40/17 R and the FD is supposed to have 50/50 weight distribution but I've never had it on scales.

The June issue of GRM magazine found 28 psi. best but could be run 40 to 24 depending on how you like your car to handle.

I seem to recall some time ago, an article by a pro-FWD racer, said to run the rears 10 psi higher than the fronts. Anybody tried that ?

iceracer wrote: I seem to recall some time ago, an article by a pro-FWD racer, said to run the rears 10 psi higher than the fronts. Anybody tried that ?

For a FWD car maybe, but not a RWD.

carguy123 wrote:

iceracer wrote: I seem to recall some time ago, an article by a pro-FWD racer, said to run the rears 10 psi higher than the fronts. Anybody tried that ?

For a FWD car maybe, but not a RWD.

Think this set-up is designed to get a FWD car, which often tends heavily towards understeer, to rotate. Unless the OP is trying to solve a specific handling problem, the last thing he would want to do is loosen the rear on a RWD car.

Note that the said article WAS for FWD.

Back from my first track event on the Z2s. For this outing I set them to 35F/33R hot psi. When cold, turn-in was not very crisp, but once they got some heat in them, that improved. Without pushing too hard my times were upwards of 3 seconds faster per lap (2.x miles, ~23 turns, 1:44 lap time) than with the old RT615s (not the K). I feel that the Z2 communicated well, had a wider useable slip angle than the old Azenis, and seem to wear more evenly than the outgoing Z1s.

When I got home, I read the latest GRM test where they indicated 36 psi is not a happy place so I'll have to play around with testing different pressures next time :|