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      07-07-2013, 11:44 PM   #419
Smiley1175
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A wider tyre doesn't mean more contact patch on the ground. It's the tyre pressures that dictate that.
A wider tyre will change the shape of the contact patch but the level of grip would remain relatively consistent. What changes is the heat build up in the tyre, as there would be less flex for the same given tyre pressure.
Going to an R-spec tyre is the biggest improvement, playing with tyre pressures is the next step for track performance.
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      07-08-2013, 01:44 AM   #420
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Quote:
Originally Posted by Smiley1175 View Post
A wider tyre doesn't mean more contact patch on the ground. It's the tyre pressures that dictate that.
A wider tyre will change the shape of the contact patch but the level of grip would remain relatively consistent. What changes is the heat build up in the tyre, as there would be less flex for the same given tyre pressure.
Going to an R-spec tyre is the biggest improvement, playing with tyre pressures is the next step for track performance.
Yes, looking at pyrometer at the moment. This tyre particular is very sensitive to pressure, but apparently not so much heat.
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      07-08-2013, 04:54 AM   #421
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Nice Steve, should be an improvement! Can't wait to see how they work out at the next track day.

Regarding PSS v RE-11, I just switched from PSS to RE-11, a little noisier but dry traction is leaps and bounds better than the PSS, not even in the same league especially on the track.

Coming from RE-11's on my 135 I couldn't wait to get rid of the PSS on my M3, Launch Control definitely got a work out to make them need replacing quicker...
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      07-08-2013, 05:22 AM   #422
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Congratulations on your new tyres

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Originally Posted by sparoz View Post
Yup - hopefully it will last till I get on the track
http://www.safercar.gov/nhtsa-saferc...e=any&wear=any

Trofeo R might have slightly greater longevity than Trofeo, but it still would be interesting to see your mileage as a street tyre. The other issue with using it daily might be debris spraying around the wheel arches, since the tyres will accumulate any and all road materials/objects once hot.

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Originally Posted by sparoz View Post
However, I was told that they are up to speed on the second lap.
I was (and still am) extremely nervous using competition rubber, given the lack of traction until operating temperature is achieved, and the fact that mistakes or misjudgements no longer occur at high speeds - but they can occur at extreme speeds. So it is a double-edged sword

Perhaps if in doubt, allow more rather than less warm up laps ... then release air after each session until you are at the target pressure, because you might not find the limit of traction (or might not want to find the limit of traction).

Good luck!
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      07-08-2013, 06:16 AM   #423
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Quote:
Originally Posted by micha3l View Post
Nice Steve, should be an improvement! Can't wait to see how they work out at the next track day.

Regarding PSS v RE-11, I just switched from PSS to RE-11, a little noisier but dry traction is leaps and bounds better than the PSS, not even in the same league especially on the track.

Coming from RE-11's on my 135 I couldn't wait to get rid of the PSS on my M3, Launch Control definitely got a work out to make them need replacing quicker...
With your car we definitely need as much traction as possible .
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      07-08-2013, 06:28 AM   #424
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Quote:
Originally Posted by timbo_3101 View Post
Congratulations on your new tyres

http://www.safercar.gov/nhtsa-saferc...e=any&wear=any

Trofeo R might have slightly greater longevity than Trofeo, but it still would be interesting to see your mileage as a street tyre. The other issue with using it daily might be debris spraying around the wheel arches, since the tyres will accumulate any and all road materials/objects once hot.

I was (and still am) extremely nervous using competition rubber, given the lack of traction until operating temperature is achieved, and the fact that mistakes or misjudgements no longer occur at high speeds - but they can occur at extreme speeds. So it is a double-edged sword

Perhaps if in doubt, allow more rather than less warm up laps ... then release air after each session until you are at the target pressure, because you might not find the limit of traction (or might not want to find the limit of traction).

Good luck!
Thanks! I don't chew my tyres out unlike some others . I tend to get twice as much milage out from my tires for some reason, but probably because I don't got WOT at every opportunity and I looked after the pressure and alignment.

I already have the spraying problem, but I am trying to be a bit more careful when I know the spraying is happening. I tend to pick them up near the edge of the road whilst parked and I am extra gentle when I start my car and tends to clear it out pretty quickly.

The tyres seems to be more sensitive to pressure than heat. As least on the road the cold grip is already better than the PSS. I would be very careful on track as numerous reports on getting greasy when the pressure goes too high and the tyre get thrashed. Camber would also be interesting, but will speed up my suspension if the first track day proof to be problematic. It would be interesting to see how quickly I can find the limit as it is important to find the feel at limit quickly so that I know what to expect.

I know I would need to be more systematic with controlling pressure especially on sprint events, and I might start running the next M3 test day like a sprint event.

Many thanks for all the tips!!
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