V4kerker

I've been running Firestone wide ovals FRT on a 2007 base coupe for MY HPDE's. I just put on a set of non-run flats (Cooper Zeon RS3-S) and this will be my first time doing a HPDE with non-run flats. Both tires are classed as UHP tires and the tread wear rating is almost the same 320 vs 300.
My question is how or will the car handle different with the non-run flats vs run flats?

Running Summit Point this weekend.

AU N EGL

tires will not be as stiff in the corners. ie you may notice some body roll or the suspension may not seem as stiff.

just go with it and have fun.

V4kerker

Thanks for the input AU N EGL. I'm hoping to get a little more grip on corner in and apex (less under steering). Right now with a little over 1k on the tires the Coopers seem to have less grip than the FireStones (ABS is activating easier). I'm hoping that the Coopers will do better when I get some heat into the tires.

This is my first year doing HPDE so I'm still learning how to be a smooth driver and getting a feel for how a car reacts to my inputs. I'm not ready for R spec tires yet and the car is a DD.

Bill Dearborn

My experience with the Firestone run flats from a long time ago showed they were softer than the EMTs and not all that different than a non run flat tire. Compared to the original EMTs delivered on the C5s the Firestones were 4 seconds quicker in the wet on the same car running an autocross on a Go Kart track than those original EMTs were on a dry track. If Bridgestone/Firestone kept up the performance in the WO RFT then you may not notice much difference.

Bill

taken19

You will definitely feel the sidewall flex. Feels almost as if the car takes a split seconds to "set" into the corner. At first it feels a bit sloppy (almost like the car floats for a second before firming up) but you will get used to it after a session or two. I went from Wide Ovals to PS2's and could even feel the difference on the street.

ZedO6

My experience as well. The Firestone runflat's are not in the same league as the Goodyears and are actually pretty decent street tires.

V4kerker

Bill I did two hpde sessions in the wet with the WO RFT and liked them myself. I'm not so sure about my new Cooper's just from the wet DD sessions they don't seem to have the same level of grip.

V4kerker

Taken19 this is going to be my challenge for this weekend. Trying to let the car and new non run flat tires do their thing and setup first before I put in to much driver correction. Seat time seat time seat time.

Thanks

taken19

Just take a couple extra warm up laps. You will get the feel pretty quick, it's not a huge difference. If your butt can detect very subtle changes, you will pick up on it and adjust without too much worry. The street tires will still talk to you so you will know the limits of the tires before you get into real trouble.

Good luck! I will be at the track tomorrow as well...

taken19

How did it work out?

V4kerker

Taken19 the first day I wish I had my FS wide ovals back on the car but I worked thur it. I went 2 tires off 4 times I think in the first session. I think my instructor had a little to do with that. He had me brake early and get on the gas early going into turn 1 so I was carrying more speed than I'm use too. The tire pressure went up 10 psig the first session 29 to 39. Tires felt greasey above 37psig. I liked Sunday's session 2 and 3 to be the best with 34 to 36psig and overcast sky.

Go to my thread on half track drill and check out my youtube clip. I got the tires talking that weekend.

The low point of the weekend was having to check my ego and let a miata pass me on the track. Better than letting the miata pass me while I'm in the tire wall.

Overall not a bad tire for its 300 ware rating but I'm no tire expert.