Cars Ferrari 488 GTLM (2017) 0.5.20201231.01

[zerobandwidth]

Well I've now driven the car at Spa and yes, it sure is skittish at the top of Raidillon, but it's driveable when you get the line right. You just have a Very Bad Time Indeed when you get up top and hit any bumps or curbs. I think lowering the car to increase downforce has wrecked the suspension. Unless someone happens to have the suspension design diagrams for a 488 GTE just lying around and ready to be sent to me in DMs, I'll change it back to be closer to the original GT3 spec (but still slightly lowered) and see what happens.

 

[efehan doagen]

Well I've now driven the car at Spa and yes, it sure is skittish at the top of Raidillon, but it's driveable when you get the line right. You just have a Very Bad Time Indeed when you get up top and hit any bumps or curbs. I think lowering the car to increase downforce has wrecked the suspension. Unless someone happens to have the suspension design diagrams for a 488 GTE just lying around and ready to be sent to me in DMs, I'll change it back to be closer to the original GT3 spec (but still slightly lowered) and see what happens.

ok it can be my fault ive choosen the old setup lol im stupid. But i think im going to wait for the next update. And i think all the gte's feel very comfortable through eau rouge and raidillon especially the kunos and the 2018 porsche rsr. But yeah im hyped for another updated very nice mod !

 

[zerobandwidth]

I worked on it for an hour last night but everything I did to bring the suspension and aero back closer to "normal" made it terrible.
It's fine if the car becomes a little bit slower overall, because that will balance it against the other GTE cars, but I don't want it to be a bouncy, undriveable mess, which is what it was. Yesterday's experiments were not worth keeping.

 

[ales100i]

Yes, i agree. It's a little to fast now, and a little to wobbly, for lack of a better word. I have no problem with the back being lively, but i believe the suspension should be a little stiffer.

 

[zerobandwidth]

Just a note for those who need the base car; it's on sale (75% off) right now on Humble Bundle until 19 August, or you can just get the ultimate edition (also 75% off).

 

[zerobandwidth]

Good news. I came up with something that seems like a better compromise between the increased downforce, decreased ride height, and not handing like it's riding on pogo sticks.

I think, since this car can be a bit tricky, I will find a way to include some example setups for specific tracks in the next release as well.

Now to figure out how to deal with its speed advantage (at low speed) vs speed disadvantage (at high speed)... If I could find a technical bulletin from, say, 2016 instead of 2019, that would be great...

EDIT: It turns out if you finally have the sense to actually search "(year) IMSA Technical Bulletin" they pop right up.
I have not yet been able to find similar documents for ELMS or WEC. (Maybe they call them something different.)

What I'm discovering in looking at this data is that the GT3 car's setup that was created by Kunos is boosted way higher than they were allowed to run in real life, at least in IMSA GTD. It looks like maybe they really did try to make it so that you could run GTE and GT3 cars together in one class in AC? Who knows. Anyway, the boost levels from the 2017 regulations will make this car faster than the GT3 across much of the rev range, but hopefully not too much faster than the other GTLM cars. It's lower boost than the 2019 regulations that I was using before, at least. So this mod description will probably be changing in v0.4 to call it the 2017 version of the car.

We're getting there, folks!

 

[zerobandwidth]

zerobandwidth updated Ferrari 488 GTLM (2015) with a new update entry:

UPDATE (v0.4.20200813.01)

I finally figured out how to slow it down just a tiny bit and correct the aero without completely ruining the handling.

Release Notes

• Aerodynamics
  • Rear wing downforce uses the same profile as the GT3 car, but was raised by 5%.
• Engine
  • Rev limiter was restored to the default value (8500 RPM).
  • Turbo boost control was recalculated based on...

Read the rest of this update entry...

 

[efehan doagen]

Hey dude im back ! I heard of your update ! Im gonna test it today, i couldnt do anything cuz of school stress and so on in germany the school started wednesday so i was dead everyday and its quite hot. Today i recovered. Very excited !

 

[Foresight]

Hello ,
i would like to know if the sound come also from the gt3 of kunos ?
in this case, do you know if i can find a proper gte sound ?

 

[zerobandwidth]

Hello ,
i would like to know if the sound come also from the gt3 of kunos ?
in this case, do you know if i can find a proper gte sound ?

The answer is in the mod description; enjoy your voyage of discovery.

 

[zerobandwidth]

ere's tonight's debut of the car on SimRacingSystem, from several perspectives:

Me! (YouTube: zerobandwidth)

Vicente da Silva (YouTube: GranTurismo Panama)

Greg Shimer (Twitch: gas300)

 

[efehan doagen]

Hey dude dont think i forgot you : J I just had no power at all because of school. So now its weekend and a few minutes ago i tested your update (ik its late af lmao) and i think this is almost it !
It feels very comfortable and if u drive through eau rouge and raidillion it doesnt spin anymore. It sticks on the ground very good and feels good but you can spin out realisticly as well ! Very well done Update. But i think there is one thing to do: getting more topspeed and maybe a bit less aerodynamic. I can go through the exit of pouhon (turn 12 i think) with about 190 to 200 with normal gte's i can maybe reach 180 so it's quite fast through the corners. After that for me that car would be done. Thank you for your nice work .

 

[zerobandwidth]

Thanks @efehan doagen! It's down to the tricky little details now, since so much of what's in the mod now is based on whatever real-world data I have been able to find, and what's left is to try to balance that with the compromises made by Kunos to put the other cars into the game. I've found that absolute top speed can be helped by simply lengthening 5th and 6th gears and reducing downforce, but yes, it will still have a slight top speed disadvantage. This is also true of the real-world car, which makes its time with superior handling and cornering. The downforce performance might be "too good" in the current v0.4 data but I also don't want to lower it too much and break the handling (again!). The devil truly is in the details. Thanks again for your contributions to testing.

 

[markonex]

Hi zero! I'm really curious to try our mod, I did something simialr on my own, just wanted to ask you what have you changed on front aero and on aero in general. I read you increased rear aero by 5%, coud you please explain to me all the other aero changes?

 

[zerobandwidth]

Hi zero! I'm really curious to try our mod, I did something simialr on my own, just wanted to ask you what have you changed on front aero and on aero in general. I read you increased rear aero by 5%, coud you please explain to me all the other aero changes?

Here is my writeup that is concealed within the aero.ini comments:

For v0.3, we have calculated a completely custom profile for the front
spoiler, based on the following assumptions:

• The Ferrari 488 GTLM has historically performed well because of its agility, therefore it probably has the benefit of better downforce.
• That downforce should be higher than the 488 GT3.
• To balance with the other Kunos cars (Corvette C7.R and Porsche 911 RSR), a starting point for the Ferrari's coefficient of lift might be the approximate average of these two, weighted slightly higher (divide by 1.95 instead of 2.00). (This was used in v0.2 but superseded by the work below.)
• A thorough study of the effect of height on the coefficients of lift and drag is available here:
  • https://www.researchgate.net/publication/228616843_Aerodynamics_of_race_cars
• Figure 3 in this paper gives a graph of the effect of height on both the coefficient of lift and coefficient of drag.
• By placing a grid on this graph and calculating the proportions of each data point to the first point in the curve, we arrive at a set of universal CL and CD multipliers for heights in the set { 0, 0.04, 0.06, 0.085, 0.095, 0.105, 0.125, 0.175, 0.22, 0.31, 0.44, 0.67 }.
• Comparing this universal data set to the existing Kunos data for the 488 GT3, the C7.R, and the 911 RSR, we can calculate an approximate curve that will balance the 488 GTLM's downforce-vs-height behavior against these other cars, such that it will be roughly balanced against the better of the GTLM cars, while outperforming the GT3 by a noticeable margin.

The resulting calculations may be viewed here:
https://docs.google.com/spreadsheets/d/1jnTxamodFrUoXCk2tkMWVcIE_dWmvdEd-_6Pgceu8zU/edit?usp=sharing

This original calculation produced front downforce that was slightly too high, so in v0.4, the CL gain on the wing surface was reduced to 0.925 while still using the custom curve that was calculated in v0.3.

Which is why, when it came time to do the rear wing, I said "Screw this" and simply reused the GT3 version's downforce profile with a simple 5% increase in CL gain.

I hope this helps answer the original question and also serves as an example of the depth of research that's gone into the mod overall so far.

 

[markonex]

Thanks for detailed feedback, I'm looking forward to try it. Downloading right now

 

[efehan doagen]

Hey Zero im back ! I'm in quarantine cuz someone in our class got corona but i have nothing so i had lots of time to drive. Today I wanted to compare your car with the urd 2018 rsr. I drove laps around spa (again xdd) with both of them but directly out of pits with warmed tyres. With the rsr my best time was a 2:20:0 which is quite fast. With your Ferrari i achieved a 2:21:20. I know the Porsche loger so that means i could be faster in the Ferrari. So lets say im 4 thenths faster cuz i know the car better, this would mean the Ferrari is perfect. I thought it would need an update but its damn good. Spa is a fast track and the Ferrari hasnt got the best top speed so that means theyre very near to each other. I think your car is perfect . But we will see in the Future if it need an update or not. Cheers

 

[zerobandwidth]

Hey Zero im back ! I'm in quarantine cuz someone in our class got corona but i have nothing so i had lots of time to drive. Today I wanted to compare your car with the urd 2018 rsr. I drove laps around spa (again xdd) with both of them but directly out of pits with warmed tyres. With the rsr my best time was a 2:20:0 which is quite fast. With your Ferrari i achieved a 2:21:20. I know the Porsche loger so that means i could be faster in the Ferrari. So lets say im 4 thenths faster cuz i know the car better, this would mean the Ferrari is perfect. I thought it would need an update but its damn good. Spa is a fast track and the Ferrari hasnt got the best top speed so that means theyre very near to each other. I think your car is perfect . But we will see in the Future if it need an update or not. Cheers

Thanks. Glad you're still safe. We just finished the car's first competitive season on SRS at Spa, and it took a lot of setup changes to make it less dangerous, but we had a great race. This track really points out some of the suspension changes that still need to happen to make it "right", but it's definitely getting close. Thanks for the feedback and stay tuned for v0.5.

 

[Scuderia kcm]

merci d'avoir pensée a nous aux fans Ferrari beau travaille je prend un plaisir fous a rouler avec

 

[Ofitus21]

Hi! So a lot of people are still reporting issues with steering wobble. People with DD wheels encountered that issue with my Formula Student car too. For me the issue had to do with the electronics.ini file. Even if your car doesn't use ABS, apparently you still need to include all the lines of code. This file should fix this issue