GTE BOP STUDY AND ANALYSIS

Andrea Terzi

Andrea Terzi

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“Balance of performance (abbreviated BoP) is a regulation and mechanism that maintains parity between competing vehicles by adjusting limits on a car's parameters, such as horsepower, weight, engine management, and aerodynamics to prevent a single manufacturer from becoming dominant in a racing class or series.” The aim of this paper is to study and understand the current rF2 GTE BoP. All 5 cars (Ferrari, Porsche, Chevrolet (C7R), BMW, Aston Martin) have been compared using raw numbers and formulas. Cars were set to be in the most similar conditions. Lowest front height combined with lowest springs and wing were used to bring the car to their limit of aero-efficiency and top speed. Wing 1 (minimum) is also the most used configuration in top competitions so it is the most significative configuration to measure. No measure were performed on driver-dependant data (such as top speed in a short straight, pure acceleration, corner Gs) to avoid human influency on final results. Ferrari 488 is used as reference for every single graph display, as using the same car for every compare makes it easier to understand data differences.

Edit to V2 (08/01/2020):
- Changed Cd and Cl to CdA and ClA (just a name change, nothing new in numbers).
- Changed C/L in L/D (that was just a mistake in naming the parameter, it is still ClA/CdA).
- Added change notes in BoP proposal to better understand it.

Edit to V3 (10/01/2020):
- Removed every VEC reference from the paper.
- We reached over 320 downloads, thanks you all for spending a bit of your free time reading our paper!
 

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Hi, Terzi!
Nice stuff. Interesting read this.
Can you tell our, how you calculated Cd, Cl? This channel not allowed in telemetry. What the math formula?

P.S. Oh man, your avatar is nice. :cool::D:oops:
 
Denis Eshchenko said:
Hi, Terzi!
Nice stuff. Interesting read this.
Can you tell our, how you calculated Cd, Cl? This channel not allowed in telemetry. What the math formula?

P.S. Oh man, your avatar is nice. :cool::D:oops:
Click to expand...
That's the same with Torque, channels are locked. There is a way to unlock them which i would like to keep secret. But i know i am not the only one doing such a thing.

Talking about formulas, i reversed the classic formula (Force=0.5*Coeff*AirDensity*Speed^2) to find Cd and Cl starting from downforce, drag and speed.
It's always nice to speak to a 787 fan, cheers ;)
 
Nice analysis!

A couple of things i would change to ease understanding is the C/L (average), which i guess you mean is Cl/Cd or L/D ratio. Then in the conclusion you suggest some changes, some values are green some are white. Maybe add the change in parentheses after the value, because some of the white values are also changed, not only the green ones.

But thanks for taking the time to do this, and will try to bump it until its recognized by S397.
 
Martin Dyrlund said:
Nice analysis!

A couple of things i would change to ease understanding is the C/L (average), which i guess you mean is Cl/Cd or L/D ratio. Then in the conclusion you suggest some changes, some values are green some are white. Maybe add the change in parentheses after the value, because some of the white values are also changed, not only the green ones.

But thanks for taking the time to do this, and will try to bump it until its recognized by S397.
Click to expand...
Thank you Martin. We will doublecheck, however the "white" which are different but not in green is because they are ratios dependent from the inputs changed, which are in green as said. Example: if you change Cd (so green), the CL/Cd (C/L) will change aswell. We put in green only what we changed to get the closer performance indexes, to underline what should be adjusted to get a specific result.
 
Fabry093 said:
Interesting analysis, why you haven't also included the new Corvette?
Click to expand...
For 2 main reasons. First of all it is still not used in most of the virtual championships and it may recive updates as it happened with 488GTE this summer. Last but not least I haven't bought it yet :rolleyes:
 
Andrea Terzi said:
For 2 main reasons. First of all it is still not used in most of the virtual championships and it may recive updates as it happened with 488GTE this summer. Last but not least I haven't bought it yet :rolleyes:
Click to expand...
Ah okay, because I think the C8 will replace the C7 in the next championships
 
Martin Dyrlund said:
Nice analysis!

A couple of things i would change to ease understanding is the C/L (average), which i guess you mean is Cl/Cd or L/D ratio. Then in the conclusion you suggest some changes, some values are green some are white. Maybe add the change in parentheses after the value, because some of the white values are also changed, not only the green ones.

But thanks for taking the time to do this, and will try to bump it until its recognized by S397.
Click to expand...
Thanks Martin. C/L was my mistake during fast writing. About white and changed values I get what you mean. Those values are different but still white because we started "our" BoP from VEC current BoP. So something may be different to the first table but marked as white just because we didn't show VEC table. I know it may be confusing but honestly we just care about absolute values and not relative changes. Thanks for your precious feedback!
 
Sorry but can someone explain what are those CI, C/L, L/D, etc... standing for ?

Maybe obvious when you speak perfectly english but as it is not my case, I can't find anything related in my own language so...
 
Andrea Terzi said:
“Balance of performance (abbreviated BoP) is a regulation and mechanism that maintains parity between competing vehicles by adjusting limits on a car's parameters, such as horsepower, weight, engine management, and aerodynamics to prevent a single manufacturer from becoming dominant in a racing class or series.” The aim of this paper is to study and understand the current rF2 GTE BoP. All 5 cars (Ferrari, Porsche, Chevrolet (C7R), BMW, Aston Martin) have been compared using raw numbers and formulas. Cars were set to be in the most similar conditions. Lowest front height combined with lowest springs and wing were used to bring the car to their limit of aero-efficiency and top speed. Wing 1 (minimum) is also the most used configuration in top competitions so it is the most significative configuration to measure. No measure were performed on driver-dependant data (such as top speed in a short straight, pure acceleration, corner Gs) to avoid human influency on final results. Ferrari 488 is used as reference for every single graph display, as using the same car for every compare makes it easier to understand data differences.

Edit to V2 (08/01/2020):
- Changed Cd and Cl to CdA and ClA (just a name change, nothing new in numbers)
- Changed C/L in L/D (that was just a mistake in naming the parameter, it is still ClA/CdA)
- Added change notes in BoP proposal to better understand it
Click to expand...
Good report from what i've read - but I would really prefer you keep VEC BOP out of this - not relevant for anyone except VEC drivers, and there is a lot more drivers in GTE than just the VEC drivers :)
Edit: and I have sent this forward.
 
Jihemme said:
Sorry but can someone explain what are those CI, C/L, L/D, etc... standing for ?

Maybe obvious when you speak perfectly english but as it is not my case, I can't find anything related in my own language so...
Click to expand...
They are all coefficient used to understand aero behaviour indipendently from speed.
ClA is for downforce, the higher means the car can produce more downforce at the same speed.
CdA is for drag and it works as the previous one.
L/D is the ratio between ClA and CdA and shows how efficiently the car produces downforce. The higher means the car can produce more downforce for the same amount of drag, or that it produce the same downforce but wirh less drag.
C/L was just a writing mistake, nothing relevant.
 
Jimmi Allison said:
Good report from what i've read - but I would really prefer you keep VEC BOP out of this - not relevant for anyone except VEC drivers, and there is a lot more drivers in GTE than just the VEC drivers :)
Edit: and I have sent this forward.
Click to expand...
Thanks for your interest Jimmi. We thought it was worth to include VEC BoP since your league is probably the top reference when talking about endurance races. However we understand your request and i will personally update the paper later today removing the VEC BoP part.
Cheers!
 
Just so I understand, the BoP presented at the end of the document is the one that is actually in place or the one that should be in place?
 
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