I have wandered through most of the STX forums lately. I started driving in AutoX late last summer. I am doing pretty well locally in my MCSC 2005 with JCW. Not great, and I know there is plenty of room for the driver to improve. Oh, and I recently installed Webb Extreme Rear Sway bar (and yes, Red does make it faster!).

My biggest improvement has been to not leave so much rubber on the course (so that more stays on my tyres!).

I had been running some OZ Forgiatas in a 17 x 7.5 with Goodyear F1 GS-D3, and I have been pretty happy with them. The wheels look great.
But I decided I want to preserve that set of wheels/tyres because the care is my wife's daily driver in the summer, and she should not have to worry about my tyre abuse. Have been shopping around for some Rota Slipstreams but they appear to be out of stock all over the place.

So I found a deal on some Motegi Traklites (16x7) and Falken Azenis RT615 (215 45 16) that I will use only for AutoX days.

Thoughts? Is this reasonable? I know I will never be competitive outside my region, but it has been fun keeping up with the big boys locally. I ran 2.7 seconds in the PAX behind the fastest time of the day (a Lotus Elise driven by a very experienced driver) so I am not complaining.

 

You just bought the wheel/tire package I want to get. Please let us know how they work out!

 

I think you'll find that the new setup is an improvement. Good choice in tires and size for an STX MINI.

Scott
90SM

 

VERY good choice!! The Motegi's are one of the lightest wheels you can buy. The 615's are one of the softest/gripiest(?) tires you can buy. I was using 15" 615's (but on Konig Heliums) for the last two years in STX and I loved them.

 

You will need to monitor tires temps and feel of the tires as they tend to get greasy after a few runs. Just buy a garden sprayer and cool them down between runs.

 

Thanks, heard about the going greasy, already have the garden sprayer. Thanks, and I will let you know how it goes.

 

If you could, give us a ball park figure on temp, humidity, overcast or clear, if you have a pyrometer, maybe track temp. I tracked all of these things with my old STU car and am interested in how much better the RT615 hold up with 800-1000 less lbs out of curiosity. I think you will love the 615's, but try to get your best run in on the 2nd run on a hot day. After that, you are fighting an uphill battle.

 

When I was still running STX, I typically had to start spraying the front tires after the 2nd run in the summer months. That was with the 215 Azenis (I went through 6 sets). I record site, weather (temp and conditions such as sunny, overcast, wind, severity of rain but not humidity), tires (to track runs/miles), swaybar settings, damper settings and tire pressures after every run. I note when I spray the tires, and if I had a passenger on the run. For the first 5 years of autocrossing I had course maps and notes also, but now I just note anything relatively unique. Parts changes, tire rotations and changes, alignments, etc are also logged by date and mileage.

I'm using 615s this year as daily street tires, plus for autocross in the rain or if my son is going with me to drive the kart (no room for Rs plus him). Same data is recorded, as always. In general, they seem to go another run before needing to be sprayed in hot conditions (80's when sunny, 90+ even when overcast).

Your results may vary. I strongly suggest creating a log book for yourself. It really helps

Scott
90SM

 

Just before selling the STI, my Dad and I autocrossed it on new 615's. It was so hot that after the second run they were so hot they stopped increasing in pressure after each run. 320hp, 3200lbs and 6 runs each. They were scorching. Sold the car the next day though. Never abused them like that before and would have been interested to see how bad the affected grip. They were brand new before the event.

+1 on the log book. PM me if you want a copy of the one I use.

 

I don't normally have a co-driver, so the tires get more of a chance to cool off between runs. Typically, I see tire pressure stabalize after 3-4 runs in most conditions with most tires. That doesn't necessarily translate to spray time for street tires or Rs. With the old 215s, it was too late. With Rs or 615s I normally won't spray until a little later.

It's not scientific, but a touch test on the front tires works for me. That, and I can feel the grip start to drop off. If you get them hot enough, you can HEAR it.

FYI, with both versions of the Azenis the peak grip didn't really arrive until after a couple of events or several hundred street miles.

Scott
90SM