Anybody Ever notice This Before??

  • Thread starter mustangxr
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406
Canada
Victoria, B.C.
skypilotrv4
Hey Guys and Gals,
I've been grinding away on the "Super" offline race, "24 Minutes of Nurburgring" lately, with lots of different cars. This has been taking me around 25 to 26 minutes, depending on the car. I can usually pull off a couple of, just under, or just over, 8 minute laps out of the 3 lap total
As you all know, you end up getting 3 laps on this one and usually you can do it without a pit stop if you take it easy on the second (wettest lap). This avoids pitting for fuel and I always start with Race soft tires which seem to give me better grip than the AI cars, and I stay with the same tires for the entire race. Because of the wet track, there is very little wear showing, until the last lap which dries right out. The AI usually run R-2 or R-1s, with some Intermediate Rains. The AI seem to pit often which enables me to finish more than 2 minutes ahead (sometimes) after 3 laps!?!?

Anyway, my big observation is that my car(s) all lose about 4 mph of top end, on the last lap straightaway, just before the finish.

At first, I thought it was the oil needed changing, so I would change the oil and sure enough, the next race I would get all my speed back on the first lap staightaway, but then, lose the same amount of speed on the last lap. Then I tried it without changing the oil, and lo and behold, the same thing happened. So, I'm now thinking that the amount of tire wear is changing the diameter of the tire and giving me less speed at the redline. Could this be possible?? Is there another explanation for this?? This has got me very puzzled.
Thanks for reading, Mustangxr
 
Worn tires increase engine rpm per tire rotation, yes.
I don't believe it's very dynamic, as you mention, sudden changes occur which should be more progressive.

This has been in GT since GT3 at least I believe.

Tire compounds also change speed per rpm.
 
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