Equation to determine PP, roughly

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I recently came across an equation that, when use correctly, gives you a number close to your car's PP.

PP = 259*(power*torque/weight)^(0.15) + (Fd+Rd)/2 - (MFd+MRd)/2

where Fd and Rd are the current front and rear downforce, and MFd and MRd are the minimum front and rear downforce.

Let's try it out with a fully tuned Jaguar E-Type.

Plug in the numbers and you get 259*(440*240/1038)^.015+([{0+0}/2]-[{0+0}/2])
That simplifies to 259(440*240/1038)^0.15
That simplifies to 259(157.26)^0.15
That simplifies to 259(2.13)
Which ends up being, low and behold, ~553.
Actual PP for the car is 513.

Keep in mind that the equation does not factor in weight distribution, which is most likely the reason for the higher result.


EDIT: Here is a better looking version:
gif.latex
 
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It might be nice to link to the forum you got that from. And it seems a little far off the mark.
 
I know weight distribution effects PP. So you are missing part of an equation. Take a FR car, put 200kg ballast in. Having it at the rear=more PP and at the front=less PP
 
If my friend HumboldtEF hadn't told me about this thread I would have never known about.


Gamer I've been working on a chart that shows the Performance Points System in a group number formula. From studding the PP numbers of all the cars and recording the changes to the pp number from changing the oil, adding parts and breaking them in to get the final pp number. After going over my notes and doing some math I found five common numbers (2-3-7-8-13). I found this to be very strange and then I started testing. From my testing I found that PP system arrange the car within a number bracket or group. The system determines the bracket/group by weight, displacement, power train (4WD). Performance upgrades as in Engine upgrades, turbo upgrades and weight reduction. Even though you are increasing the performance the car will always stay within its group number. From what I see the pp system allows the cars to perform their best engine wise from 85% to 100%, 100% the optimal. I also found that the pp system shows the advantages and disadvantages of adding parts. I’m still in testing of this chart. My testing has been very successful; the cars that I've tuned to run within a group number have performed better than the cars that have been de-tuned to fit with in that group number. I’m still in testing of this chart but so far I haven’t found anything wrong yet. I’m handing this chart out to just a few to get some feed back before I release it. If you would like a copy pm me a e-mail.
 
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That is fascinating. Sounds awfully similar to what Shift 2 uses, but similarities have been found before.
 
Here's one I came up with doing a regression on the PP of all cars, PP = 770.57*(hp/kg)^.359. Doesn't work too well for the Jaguar example but most others it does. This formula clearly shows how the 2J has too few PP. I suspect the aero factor goes inside the brackets along with power.
 
The PP formula works on the number bases of even and odd numbers. For example I tuned two BRZ’s both with ECU, Stage 1 engine, full air and exhaust parts. Though one has the aero kit installed, the one without the aero kit is at 473pp and the one with is at 482 pp. Both running at 100% power no de-tuning of the motor. As we all know you can change the pp of the car just buy moving the aero up or down, the car that at 482pp can move the pp in a group number of seven. Even though both are running at the same power levels the only difference in performance is in handling due to the aero kit. A slight difference though a difference never the less.
 
Polsixe
Here's one I came up with doing a regression on the PP of all cars, PP = 770.57*(hp/kg)^.359. Doesn't work too well for the Jaguar example but most others it does. This formula clearly shows how the 2J has too few PP. I suspect the aero factor goes inside the brackets along with power.
Click to expand...

That doesn't take torque into account, which we know PP does.
 
I would like to release the chart but I haven't gotten any feed back yet.
 
Polsixe
But horsepower is torque x rpm, so the missing variable is rpm.
Click to expand...

Take a Gillet Virtego. Fully tune it and it's PP drops, because it loosed so much torque even though it increases power.

See what I'm getting at here?
 
Maybe some calculus is needed for the area under the curve figures.

That said I have a hunch cars with Fat/flatter power curves have better value PP scores than cars with Spikey short power curves....

Maybe this is most evident in the way a restricted engine car tends to out perform a "natural" car.

(Hmm did I just contradict myself inside 60 seconds - that's performance you can trust)
 
I'm sure that 'base grip' adds quite a bit to the PP equation. Just about all of the GT-R R35 variants have high PP numbers considering the weight and power of the cars. You can see it in LMPs really easily by matching the specs of all the cars. The R8s and the Bentley have high PP numbers for their stats compared to an Audi R10 (low PP for its stats).
 
TexasTyme214
I'm sure that 'base grip' adds quite a bit to the PP equation. Just about all of the GT-R R35 variants have high PP numbers considering the weight and power of the cars. You can see it in LMPs really easily by matching the specs of all the cars. The R8s and the Bentley have high PP numbers for their stats compared to an Audi R10 (low PP for its stats).
Click to expand...

In account of the GT-R R35 pp it's the way the car puts the power to the ground. The R10 had a number of different regulations to follow for the year it competed as well R8 and the Bentley. As you can see those two cars has a much higher power number than the R10 so in turn the pp number will be higher even though the R10 as better torque numbr than both cars.
 
Hi I’m Maurice J. otherwise known as Zuel on the forms or GTP_Striker on the track. I would like to share something very interesting that I found out about the PP system. As we all know the Performance Points system (PP) was developed to determine the performance of the cars, it also groups the cars according to performance. I may have found a way to break down the formula to see how this is done. From what I found so far the PP system will keep all the cars in the respective groups as long the cars are ran between 80/100% power no matter what parts are added. I also found that the PP system will also lower the performance of the car pending on how the motor is tuned after the starting displacement. I have worked up a chart to attempt to better understand the grouping system and work on a formula on how it is done. I got it as close as I can at the moment; I have gotten everything within one which is still a lot which is a factor of 1000. I’m still working on getting everything to zero which will show the formula how it was done. I and one other tested the chart buy stepping up the tunes to see how the car falls in a group of numbers. All the cars that were tested are within in or out the a group number buy a number of one while running at 100% power, 100% aero and 100% weight added. This is my first attempt at the chart; I’m still working on a better way to have the chart read. You can download the chart at the link below. I'll do my best to post the chart here.

View attachment GRAND TURISMO PERFORMANCE POINTS SYSTEM CHART.zip



OC ECU SIM SAF RAF SEM CC/S SE TSRE TRE ETS1
8pp 2PP/9PP 2PP/8 2PP/10PP 2PP/13PP 1PP/12PP 2PP/11PP 3PP/12PP 2PP/12PP 3PP/15PP 4PP/10PP

ETS2 ETS3 LRRT MRRT HRRT WWR CH WRS1 WRS2 WRS3
4PP/17PP 1PP/9PP 10PP/47PP 5PP/20PP 1PP/32PP 0PP/2PP 0PP/1PP 2PP/12PP 1PP/8PP 0PP/5PP

AK
8PP ( GROUP NUMBER OF 7)


Street Car Performance Points Group Chart

216/224 229/237 242/250 255/263 268/276 284/292 297/305 315/323 328/336 341/349 354/362

370/378 383/391 396/404 409/417 422/430 435/443 448/456 461/469 474/482 487/495 500/508

513/521 526/534 542/550 555/563 568/576 581/589 594/602 607/615 620/628 633/641 646/654

659/667 672/680 685/693 698/706 711/719 724/732 737/745 750/758


Note the group number for the Aero Kit can be moved from 1pp to 7pp even though the common number is 8. PP numbers listed in yellow give the average PP number for each part in any given group. PP grouping numbers are in blue.
Oil Change (OC) Electronic Control Unit (ECU) Sport Intake Manifold (SIM) Sport Air Filter (SAF)
Racing Air Filter (RAF) Sport Exhaust Manifold (SEM) Catalytic Convector: Sport (CC/S)
Sport Exhaust (SE) Titanium Simi-Racing Exhaust (TSRE) Titanium Racing Exhaust (TRE)
Engine Tuning Stage 1-3 (E-ST1/3) Low Range RMP Turbo (LRRT) Mid Range RMP Turbo (MRRT)
High Range RMP Turbo (HRRT) Window Weight Reduction (WWR) Carbon Hood (CH)
Weight Reduction Stage 1-3 (WRS 1-3) Aero Kit (AP)
 
After looking at the post better Dl the zip to take a look at the chart.
 
I got a number of emails asking how does it work with GT. In order to use the chart correctly you must start with a fresh car to see how the chart works. you must start with a oil change to get the being group number.
 
gamerdog6482
I recently came across an equation that, when use correctly, gives you a number close to your car's PP.

PP = 259*(power*torque/weight)^(0.15) + (Fd+Rd)/2 - (MFd+MRd)/2

where Fd and Rd are the current front and rear downforce, and MFd and MRd are the minimum front and rear downforce.

Let's try it out with a fully tuned Jaguar E-Type.

Plug in the numbers and you get 259*(440*240/1038)^.015+([{0+0}/2]-[{0+0}/2])
That simplifies to 259(440*240/1038)^0.15
That simplifies to 259(157.26)^0.15
That simplifies to 259(2.13)
Which ends up being, low and behold, ~553.
Actual PP for the car is 513.

Keep in mind that the equation does not factor in weight distribution, which is most likely the reason for the higher result.
Click to expand...

I wish i took more notice in math class, it is way over my head!
 

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