GT4 vs Forza's tires

[Thatman]

Well after many, many, many test I and the person who helped me have come to the conclusion that Forza's racing slicks are R2s in GT4, and that in Drag racing on GT4 anything after R1s give only minimal decrease in time, while in Forza time goes down by a second and a half. However we are still unsure what the DOT-spec and Y-rated tires equal. Oh and I figured this go here anyways cause it deals with both of them.

 

[sucahyo]

How about wheel spin? do the car spin at the same gear ratio? or does it spin until same speed?

 

[Thatman]

Well that’s kind of where it gets odd, in Forza if you take off the TCS, time on the drag is decreased and all is well, put it on, your time will suffer. However the opposite happens in GT4. In Forza wheel spin is taken care of by severely cutting off the engine, GT4s is better in that aspect because it doesn't do that as much.

 

[sucahyo]

I see, still interesting though 👍.

 

[amp88]

How did you come to those conclusions? Testing theories, methods and results...?

 

[Thatman]

Well mainly we took the exact same car, the Dell V12 race car for example, I then did the best I could on Forza, then my freind worked his way down until he hit R2s. We then used another race car and the same thing came up. Finally we used non race cars and equipped them with Forza's Racing slicks, he used R1s but then after about 3 laps or so on Tsukuba he changed to R2s and came surprisingly close to the same time as me, we figured that Forza’s and GT4’s times are ever so slightly off as well for human error, and came to the conclusion that R2s do indeed equal racing slicks on Forza. I mean if you want to try it yourself, R2s on GT and Slicks in Forza should produce relativly the same times give or take a second or 2.

On a side note, he figured out that to get lb/in (spring rate in Forza) from Kgt/mm you times it by 55 and vice versa.

 

[sucahyo]

Are there any economy tire like in Forza?

 

[amp88]

Let me get this straight. You did a time on Forza and he tried to match it on GT4? Why didn't one of you do both times? Hasn't it occurred to you that you may not be as quick as each other?

 

[Thatman]

Let me get this straight. You did a time on Forza and he tried to match it on GT4? Why didn't one of you do both times? Hasn't it occurred to you that you may not be as quick as each other?

Well see he can’t get the same times as I can get on Forza yet on GT4 we get very, very close check out this thread:https://www.gtplanet.net/forum/showthread.php?t=86440
He doesn't do too well on Forza mainly because the ABS systems are handled differently in it and his driving style doesn't transfer well.
Also I did do a race yesterday using the 800tt and the Viper GTS with about 900 some hp and I got on Forza a 54.6** and on GT4 a 53.8** at Tsukuba.

@sucahyo, well we aren’t sure what econs are like in Forza, because they might be the stock tire and they might be y-rated tires. But that doesn't apply to every car because for example, the viper comes stock with something around like sports soft and something like a Civic is going to come stock with something like econs.

 

[flamve]

alright I get it, I suck at forza. Jeez.

 

[sucahyo]

I see.
What I know about GT4 tire is this (from hacking):
- front and rear tire have different grip value
- race car tire have more grip even on the same tire kind, S3 on minolta has more grip than S3 on supra.

 

[Thatman]

@sucahyo
What do you mean by that?

 

[amp88]

@sucahyo
What do you mean by that?

I imagine what he means is that the front and rear tyres are often different widths (wider tyres on the rear than on the front in most cases) and that tyres are different sizes across different cars.

 

[sucahyo]

What I mean is the front and rear tire has different grip value.

The variable that I search (hack) is the value of grip that is changed when we change the tire. This variable in N2 has more value (ie grip) than N1, S1 has more value than N2, an so on.

By seeing this variable I can tell about how much grip the tire for spesific car has.

an example of grip value
00B1F230 3F990000 front
00B44530 378F0000 rear

read as 39231 front / 36663 rear.

other variable:
00B1F258 CD front
00B44548 D1 rear

If this variable is the same as GT2, the first one would be slip percentage, the second one would be multiplier of tire grip constant.

 

[Thatman]

Well thanks for the explanation, but we still got similar times using the same race cars, and close with "stock" production cars. Thats how tire witdth and size is kind of accounted for.

 

[sucahyo]

I see.