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A question about the tyres, should I go for even out the psi or temperature? As it is now if having 28psi all around (when warmed up) my left front is at between 91-93 at all times, my rear right is below 80 and the other two in between 80-85.
Or should I fiddle with pressure to get a more even temp all around?
 
A question about the tyres, should I go for even out the psi or temperature? As it is now if having 28psi all around (when warmed up) my left front is at between 91-93 at all times, my rear right is below 80 and the other two in between 80-85.
Or should I fiddle with pressure to get a more even temp all around?
Hey man,
this question bothered me too and I decided to do a quick math about it.
What is that:
I looked into the ini-files from the Diablo SE30 mod and searched for numbers...
I found default data for:
1. "tcurve" = table for Griplevel and Temperature: 65-85°C = 100% Grip!:
[°C | %]

0 |0.80
20 |0.92
40 |0.95
50 |0.98
65 |1.0
80 |1.0
85 |1.0
105|0.97
140|0.95
160|0.88
200|0.82
220|0.80
250|0.60

Graph:
GripLevelTemperatureGraph.JPG

2. Default data for "Rolling Resistance" = "12" and for "Pressure_RR_Gain" = "0.55":
So 12 is 100% at optimal pressure, 100% = 12+0.55*0 psi ; 102% = 12+0.55*(-1 psi) and so on:
[psi change | RR in %]

-5 | 1.23
-4 | 1.18
-3 | 1,14
-2 | 1,09
-1 | 1,05
0 | 1,00
+1| 0,95
+2| 0,91
+3| 0,86
+4| 0,82
+5| 0,77
Graph:
RollingResistancePSIGraph.JPG



3. "Footprint loss per PSI" = "0.00045" and now I have a problem... What is the footprint?!
Well I will go with just the "Tire Width" = "0.245" and take that as footprint... Also I take footprint as grip. So 100% footprint = 100% grip!:
[psi change | footprint in %]

-5|1.09
-4|1.07
-3|1.06
-2|1.04
-1|1.02
0 |1.00
+1|0.08
+2|0.96
+3|0.94
+4|0.93
+5|0.91

Graph:
FootprintPSIGraph.JPG


So after doing that: what is the conclusion?!
Let's say you need -4 psi to get the tire warmer and in the "perfect temp area".
So your tire is 50°C but would need 65°-85°C to be at 100%. It's already at 98% grip!
-4 psi would do that:
1. increase the rolling resistance by 18% which will definitely decrease your top speed!
2. increase your footprint by 7%. (if the footprint isn't just the tire width but "tire width * 2-3mm" that would only be ~3%!)

If my math is "correct" you will gain 2% grip, have almost 1/5 more resistance and I don't know about the footprint-impact .

- Conclusion:
1. Cold tires are a problem!
2. "Almost warm" tires doesn't have such an impact as you might think!
3. Too hot tires are worse than not completely warm tires!
4. The grip won't be influenced much by the PS! (footprint-impact?!)
5. But the Rolling Resistance will be influenced heavily!

6. You trade top speed for grip but loose more top speed than you gain grip!

After doing that I will go for slightly colder tires and optimal pressure all the way! And keep the "pressure priority" to optimal and higher, not optimal and lower! :)

PLEASE tell me if that is correct, should I create another thread for this? Oh man... Why did I do that?!:O_o::roflmao:

@Lars Rystedt edited my post :inlove:
 
Last edited:

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