[Poll] Car selection for an upcoming sports car league

Dennis · Jun 28, 2014

Before you vote, please consider:

Every LMP driver will need to purchase URD EGT
No performance/balance changes by us; EGTs will stay the way they are, as provided by Ales

Fairly soon RD will hold its first Virtual Sports Car Championchip, in the spirit of TUSCC. It will consist of four 4 - 6 hour long races, and allow for driver swaps.

For this, we would like to have your input on the car selection. Do you prefer different cars per class, or perfect balance? And are paid cars OK, even if you race in a different class?

Please note that this league is not intended to be a successor or replacement of the VWEC/RDLMS, and will run as a completely separate entity.

More details will be released in the near future.

David O'Reilly · Jul 2, 2014

Frederic Schornstein said:
As I know from @Simon Christmann who looked at both URD tyre files they are both exactly the same, therefore your results seem pretty accurate as you couldn't find any major diffrence between them.
Backs up my personal oppinion, that you can push the front of the URD cars much harder without getting a bit penalty in wear or in tyre temps, which could cause you trouble one or two turns later.

Nice way to find out the diffrences in an more objective way

P,S, Maybe the enduru tyre is now a bit diffrent as it was a few builds ago, but at least the diffrence should be really small

Maybe theres a sight placebo effect here?
I start out on the endurance tyre thinking I wont push as hard as its an endurance tyre. Then like magic it lasts a little longer.
The sprint tyre I lean on harder and it goes off a bit. Funny how our brains work.

Frederic Schornstein · Jul 2, 2014

David O'Reilly said:
Maybe theres a sight placebo effect here?
I start out on the endurance tyre thinking I wont push as hard as its an endurance tyre. Then like magic it lasts a little longer.
The sprint tyre I lean on harder and it goes off a bit. Funny how our brains work.

Yes, it was the same for me I thought the temps were not going that high, but I doubt that there is a diffrence in the tyres, because wear rates and laptimes are very close.

As you didn't know, that they are not diffrent it shows, that your analysis should be pretty objective, because that was one of the results

Simon Christmann · Jul 2, 2014

I looked on car release ago into the files. But it seems like there are no changes

The same is between inters and wets. The main difference is just in your mind. You think its a tire with different characteristics and then you drive the car slightly different. That the very same vary in time and wear

David O'Reilly · Jul 2, 2014

Simon Christmann said:
I looked on car release ago into the files. But it seems like there are no changes
The same is between inters and wets. The main difference is just in your mind. You think its a tire with different characteristics and then you drive the car slightly different. That the very same vary in time and wear

Bit like in Race Pro, (BTW which I respect big time as its the best sim on a console) but its wet weather was graphic only with wipers and different default setups!

Dennis · Jul 2, 2014

Thanks for the post @David O'Reilly

I took some time now to compare the ISI tires with the EGT tires by looking solely at the files and it supports your experimental results.

ISI Corvette Slick vs EGT Corvette Sprint:

The slip curves are identical
Mostly "placebo changes" like:
ISI: Width=0.299, Radius=0.3252
EGT: Width=0.300, Radius=0.342
Just 2 big differences:
EGT tires are pre-heated to 65°C, ISI start with 30°C
Front WearRate (rear is 1.4e-7 for both):
ISI: WearRate=1.4e-7
EGT: WearRate=1.040e-7
(this pattern is the same for all tires, so if ISI is 1.xe-y, EGT is 1.0xe-y at the front)

And I'm not saying these "placebo changes" are a bad thing: ISI probably had a lot more data and expertise to develop a tire, so it's a good thing that the EGT one is so similar.

EGT: Difference Sprint vs Endurace:
In over 7000 lines of data there are only 14 lines with differences. For example:

DegradationCurveParameters=(343.15,3150) //(Endurance)
DegradationCurveParameters=(342.15,2900) //(Sprint)

No idea how big the impact of such changes is, but I would guess it's rather small

EGT: Difference Wet vs Inter:
None. At all.

Suspension (.PM) ISI vs EGT:
Looks quite similiar, but didn't look closely.

Conclusion:
The handling difference probably comes from the changes in

Front tire wear
Edit: Drag
Initial tire temp (for first few laps)
~~Axle track (30cm wider)~~ (edit: it's only 4cm)
Base setup/setup options (different ranges to choose from)

Disclaimer: When I write "placebo changes" then it's because I'm guessing they don't have a big impact based on the magnitude of the value/changed digit(s). But I may also be wrong.

Frederic Schornstein · Jul 2, 2014

Dennis Coufal said:
Thanks for the post @David O'Reilly

I took some time now to compare the ISI tires with the EGT tires by looking solely at the files and it supports your experimental results.

ISI Corvette Slick vs EGT Corvette Sprint:

The slip curves are identical

Mostly "placebo changes" like:
ISI: Width=0.299, Radius=0.3252
EGT: Width=0.300, Radius=0.342

Just 2 big differences:
EGT tires are pre-heated to 65°C, ISI start with 30°C
Front WearRate (rear is 1.4e-7 for both):
ISI: WearRate=1.4e-7
EGT: WearRate=1.040e-7
(this pattern is the same for all tires, so if ISI is 1.xe-y, EGT is 1.0xe-y at the front)

And I'm not saying these "placebo changes" are a bad thing: ISI probably had a lot more data and expertise to develop a tire, so it's a good thing that the EGT one is so similar.

EGT: Difference Sprint vs Endurace:
In over 7000 lines of data there are only 14 lines with differences. For example:

No idea how big the impact of such changes is, but I would guess it's rather small

EGT: Difference Wet vs Inter:
None. At all.

Suspension (.PM) ISI vs EGT:
Looks quite similiar, but didn't look closely.

Conclusion:
The handling difference probably comes from the changes in

Initial tire temp (for first few laps)

Front tire wear

~~Axle track (30cm wider)~~ (edit: it's only 4cm)

Base setup/setup options (different ranges to choose from)

Engine (EGT uses the rF1 engine model. Sidenote: BES uses the new one )

Disclaimer: When I write "placebo changes" then it's because I'm guessing they don't have a big impact based on the magnitude of the value/changed digit(s). But I may also be wrong.

Have you looked at downforce values in any sort, because that seems fairy diffrent.
I noticed as well, that the peak temps are much higher on the ISI Corvette.
Very interesting that the wear rate is so diffrent on the front tyres on the EGT, which doesn't make a lot of sense to me

The biggest diffrences for me are braking where it is much easier to lock a tyre on the URD Vette, high speed downforce seems to be higher on the URD car and the low speed traction and then of course the low front deg.

The URD cars are definetely a lot faster in race trim.

Dennis · Jul 3, 2014

Brakes:

Code:

EGT:
BrakeResponseCurve=(-98,300,590,1110)
BrakeTorque=4330

ISI:
BrakeResponseCurve=(-220,485,530,1360)
BrakeTorque=5234.4

BrakeResponseCurve:
1-Cold temperature (where brake torque is half optimum)
2-min temp for optimum brake torque
3-max temp for optimum brake torque
4-and overheated temperature (where brake torque is half optimum)

=> The EGT brake torque builds up much more quickly:
Temperature difference from 50% torque to 100%:
ISI: ~700°C
EGT: ~400°C
Might explain why your lock up

Wing/Aero:
In short: 10 times less drag (0.00x vs 0.0x) while having slightly more negative lift ("downforce").
Good observation

Frederic Schornstein · Jul 3, 2014

Dennis Coufal said:
Brakes:

Code:

EGT: BrakeResponseCurve=(-98,300,590,1110) BrakeTorque=4330 ISI: BrakeResponseCurve=(-220,485,530,1360) BrakeTorque=5234.4 BrakeResponseCurve: 1-Cold temperature (where brake torque is half optimum) 2-min temp for optimum brake torque 3-max temp for optimum brake torque 4-and overheated temperature (where brake torque is half optimum)

=> The EGT brake torque builds up much more quickly:
Temperature difference from 50% torque to 100%:
ISI: ~700°C
EGT: ~400°C
Might explain why your lock up

Wing/Aero:
In short: 10 times less drag (0.00x vs 0.0x) while having slightly more negative lift ("downforce").
Good observation

Sorry got my words mixed up. It is much easier to lock up on the ISI Vette. With the URD Vette you can pretty much stay on full brakes the whole time even over bumps etc.

If you drive both cars on the same track, you will find out, that they are very diffrent

The changes have a huge effect. I did show @David O'Reilly two videos one with the URD Vette and the ISI Vette at Bahrain. The laptime was the same, but the URD car had no real setup, so there is more in it.
I won't post them here as they are not really representative, because the URD lap was quite slow compared to what is possible with the car and the ISI lap was close to what is possible with the car.

Dennis · Jul 3, 2014

Frederic Schornstein said:
Sorry got my words mixed up. It is much easier to lock up on the ISI Vette. With the URD Vette you can pretty much stay on full brakes the whole time even over bumps etc.

Ok that also makes more sense

Then it's the additional 1000 Nm in brake torque the ISI car has.

If you drive both cars on the same track, you will find out, that they are very diffrent

Yes that's true, but I would guess that the ISI Vette with EGT tires would still drive quite similiar (except for front wear).
It should be mostly the drag and downforce that affects the handling in this case

Edit: Both cars use the same engine; EGT only has a slightly worse heat transfer (oil/water)

Matt Horst · Jul 3, 2014

Dennis Coufal said:
Brakes:

Code:

EGT: BrakeResponseCurve=(-98,300,590,1110) BrakeTorque=4330 ISI: BrakeResponseCurve=(-220,485,530,1360) BrakeTorque=5234.4 BrakeResponseCurve: 1-Cold temperature (where brake torque is half optimum) 2-min temp for optimum brake torque 3-max temp for optimum brake torque 4-and overheated temperature (where brake torque is half optimum)

=> The EGT brake torque builds up much more quickly:
Temperature difference from 50% torque to 100%:
ISI: ~700°C
EGT: ~400°C
Might explain why your lock up

Wing/Aero:
In short: 10 times less drag (0.00x vs 0.0x) while having slightly more negative lift ("downforce").
Good observation

I think this is why it feels so much better to me with low abs.

Christian Michel · Jul 3, 2014

Hm i would love to see all Assists banned, don't know really why we are driving with them.
Ok, its maybe a bit harder for new guys to get in but it's so much more realistic...when i tried it the first time without ABS as example some years ago it was kinda weird but you will get along with it really quick.

Maybe we could do here a little poll about this, don't know how the other guys are thinking about this? Cause the Problem is if i do drive without Assists, its more fun to me but its slower :/ And with Assists it feels wrong for me as as example here you can brake into corners how it is not possible in real without ABS, you can get there several tenths in one corner - had this in some league races already.

Low ABS is such a huge difference to without, i mean even with low abs you can put the brake flat down without any locking.

April Dillon · Jul 3, 2014

Agreed there, Christian. The use of traction control is used in these types of cars for real, but the ABS is such a huge difference, I'd suggest living without it. Especially as the EGT cars' braking at 100% pressure isn't grip limited in straight lines. It's very easy to hold them at full brake force in a straight line, which is perfectly rookie friendly.

Christian Michel · Jul 3, 2014

April Dillon said:
Agreed there, Christian. The use of traction control is used in these types of cars for real, but the ABS is such a huge difference, I'd suggest living without it. Especially as the EGT cars' braking at 100% pressure isn't grip limited in straight lines. It's very easy to hold them at full brake force in a straight line, which is perfectly rookie friendly.

Im talking about the TC as well

if everyone uses it, as it looks like, i will need to use it as well...but to be honest, especially the URD Cars feel even without TC planted on the track.

Simon Christmann · Jul 3, 2014

Christian Michel said:
Im talking about the TC as well if everyone uses it, as it looks like, i will need to use it as well...but to be honest, especially the URD Cars feel even without TC planted on the track.

Even in heavy rain you can drive the urd cars pretty good with out TC. You only need the shift earlier to reduce wheel spin. But this is something you would do in a real car too.

Richard Hill · Jul 3, 2014

I do agree with the assists I think we shouldn't use them, other than if the real life series uses them then maybe we could use them. But for race series with out them then I think that we shouldn't uses them.

Frederic Schornstein · Jul 3, 2014

Richard Hill said:
I do agree with the assists I think we shouldn't use them, other than if the real life series uses them then maybe we could use them. But for race series with out them then I think that we shouldn't uses them.

I think we are talking about GT2 racing here and in GT2 TC is allowed and ABS is not allowed. In GT3 you can use TC, ABS and some cars even have stability control.

I can understand @Christian Michel that he likes the challange of no TC and it is fun.
I drove two open wheel club events this week and both times low ABS and TC was allowed, but I never thought 1 second about using them, because you don't have them in the real world.

But we are not living in a perfect world and we will have slower and faster, more experienced and less experienced drivers and I think it will be a disadvantage for the slower and less experienced drivers, if you can't use TC especially in wet conditions and they do use it in the real world, so why should we ban it?!

TC doesn't give you a noticeable performance boost, if you are rubbish in the corners TC won't solve it and most probably you won't realize your mistakes, but it adds a bit of safety for less experienced drivers and keeps more drivers in the game, which makes for a nicer race and can avoid incidents.

ABS is a diffrent story it allows you in most cars to just slam the brakes until the APEX and ruins racing, because outbraking is nearly impossible and it is already a hard thing to do in the URD cars as you can be a lot more aggressive on the brakes without locking up.

Richard Hill · Jul 3, 2014

I do understand was just my two cents.

I've not driven the URD cars that much really so still in the getting to know the carictoristics of the cars, will know a lot more after Bahrain.

Christian Michel · Jul 3, 2014

Hm i understand the side of safety and the thing that it's easier for some slower guys but the best example is the Lola LMP1. I tested it yesterday some Laps...at the Beginning i thought wow, very hard to control out of the Corners....after some Laps i got the feeling and got faster and faster but if i would have used TC it would have been so easy to control this (even with low TC) - and this is the point where good drivers can make the difference.

Frederic Schornstein · Jul 3, 2014

Christian Michel said:
Hm i understand the side of safety and the thing that it's easier for some slower guys but the best example is the Lola LMP1. I tested it yesterday some Laps...at the Beginning i thought wow, very hard to control out of the Corners....after some Laps i got the feeling and got faster and faster but if i would have used TC it would have been so easy to control this (even with low TC) - and this is the point where good drivers can make the difference.

To be fair the TC on the Lola is not working pretty well and I would love to see no TC on the Lola, because it is close to an open wheeler in terms of driving.

At the moment you can't disallow aids per class, but maybe there is a way for @Stefan Woudenberg to "deactivate" TC in a way, that no matter which TC value you set you are on your own.
LMP1 is the top class and I would expect drivers to drive without TC. I haven't driven the car with TC really, because at the moment it is not working properly. It first takes a bit of power away, but you can still easily spin it on low TC suddenly. It is not really an aid at the moment