iRacing Chat

[Sarsippius]

I saw you recommend 160kPa hot pressures for the Porsche, any idea for the GT3s? I assume with all the aero you'd need something higher.

I've only practiced 2-3 hrs with the Merc prior to this but it feels more driveable or forgiving now but the change has really thrown a spanner in the works preparing for the Sebring 12hr this weekend.

[renesis37]

I'm sure it has. Such a huge change in the handling.

As you say more pressure = less load sensitive so more effective down force but I think the model is a bit broken with regards to sensitivity to small pressure gains so I would think around 160 to still be optimal. I could be wrong, let me know when you work it out

They need to make it worse on cold tyres to make it more realistic with hot tyres and small pressure changes, probably not going to happen as they did it for a season in the V8 and people couldn't even do an out lap. But for that season the track temp made hardly any difference in pace, maybe 2 seconds from 50c to 25c ! they know how to fix the temp sensitivity issues but it just isn't worth it as the average driver wouldn't be able to complete the first lap cleanly. I asked Elliot Skeer about the cold tyre grip in the Porsche and he said it's super sketchy IRL and far worse than iRacing and you really have to get the pressures up before you can lean on it. All speculation on my part of course, I like to think about these things to have a break from thinking about work..

[Sarsippius]

David Williams from VRS made a setup which we used and it worked pretty well. Starting pressures were 140-145 and hots ended up about 165-170 which seemed to work well in practice. However once the track started rubbering up it got really greasy, it seems quite extreme now, only 20 minutes with a lot of cars on track and grooves were getting dark and there were marbles and dust everywhere. I can't remember but have they ever said dirt on the track effects grip?

We were really struggling towards the end of stints so my team mate started dropping the pressures, by the end of the race we were down to 130-135 starting and around 145 hot which seems pretty low but seemed to make a big difference for the better.

Something I noticed and it didn't seem pressure dependent was turn in under braking. Brake too deep by only a few metres and then try to turn in whilst the fronts were still loaded up and it just wouldn't turn at all, it was quite dramatic and hard to deal with. I really had to make sure I had my entry speed right, getting off the brake and trailing only a little to the apex.

I think these new tyres are forgiving in one sense that you can make mistakes and not lose the car but quite unforgiving in another sense that there's a narrow optimum range at any point and you really have to work hard to keep it in that band at all times.

As for the race it turned out to be a pretty good one, there were the usual incidents and close calls but starting 21st in class we nabbed 5th by the end

I tell ya, the first hour of a race like this with 60 cars on track, battling with cars in your class and having the DPs come around the first couple of times is something else, bloody tough!

[Duke]

Great run Sars, I wish I had the time to do some of these special events as they sound like great fun.

Yes the dirt on the track does affect grip levels.

I also heard guys were dropping pressure in the GT3 cars by around 20kpa when they were working on setups. So sounds like you worked out that works too.

Did you notice a drop in lap time like they mentioned in the new build notes, it's meant to to be approx 2secs slower with the tyre changes?

[renesis37]

Wow 145 hot, thats low. Must be something funny with the GT3 and a well used track. The C7 liked 158kpa like the porsche apparently. I do think they need to make the tyre wall slightly more responsive on some of the cars, but not by too much otherwise we would be back to weird physics land.

Good job though, I wish I the time too. I got asked to drive but had to do family things.

[Sarsippius]

The best I did on race fuel practice prior to the update was high 1's, after the update it was low 3's so around 1.5s.

Interesting thing in practice, cold was quick for a couple laps before dropping of and then they'd slowly get quicker and quicker, one session I did my pb on the penultimate lap before pitting. This seemed to match your comments on the Porsche rens. The race with a rubbered in track was completely different though but times were pretty consistent once we adjusted the pressures.

The debris was crazy though, maybe I should upload a snippet of video.

[Jiminee]

Debris was bonkers, it looked like a rally cross track in the mirrors.
Took me a while to realise why it looked like I was smoking going down the straight - was not smoke, just ploughing through the dust.

[Sarsippius]

For anyone curious, note this is only an hour into the race and it's already like this. I start off in the car following me before switching to my view, I've never had a windscreen that dirty before!

[NeilPearson]

Nice work Sars!

I entered with hz's team, and We ended up in the bottom split. I qualified 5th with a 2.2.3 and worked my way to a 58 second lead by the 2 hour mark. Came back at the 8 hour mark, and we had a few incidents, got punted by another car, and we were a lap down in 6th. I jumped in and the team decided i would finish, so I did a 4 hour stint and got us back to 2nd, about 1:45 behind the lead.

[Sarsippius]

Well done Neil, sounds like you could have been in a much higher split, 4hrs is a bloody good effort too!

[NeilPearson]

My road irating isn't high, and neither was my team mates so it's all good.

I had forgotten how much I love endurance racing. Just belting lap after lap after lap. So good, if I feel comfortable I can just go. 4hrs went so quick. I was surprised when it was over.

[renesis37]

Nice job. Looked like fun, that debris though.. something going on there. I'm worried about the low pressure thing with the GT3 tyres, the porsche doesn't seem to behave that way for me. I dropped pressures on my race set to 152 hot and it was slower, couldn't load up the front properly.

[renesis37]

I don't agree with it. If all they did is fudge the sidewall height the tyres would feel much worse than they do and everything would be off. The complaint that they "feel very spongy in the first fifteen degrees of rotation" is also known as slip angle modelling, and it is probably more like 10 degrees.. The old tyres never flexed right, the current ones might flex a little too much but I'm sure they will work on it. And on the other point to put a similar racing slick to another car they would have had to change the compound and physical parameters of the tyre, if it was a sound model to begin with not much else would need tweaking. I personally think all the cars felt the same before this build more than they do now and had to be driven only one way to be fast, now you can have radically different setups and styles be close in times, you generally need to slide the car slightly to be fast and sit on the optimum slip angle of about 10-15 degrees, each car behaves different in that state.

I think people just aren't getting all there is out of the setup, lowering pressures to fix an issue is ultimately slowing down the car a little when you should be fixing it other ways. The model is far from perfect and the pressure issues are real, the pressures are a little too low and as soon as it goes above a value it gets really greasy feeling but it does not deserve the hate. I bet norbs could even drive the cars now

[renesis37]

On that lst point I haven't driven the GT3 properly yet.. get the salt shaker out

[renesis37]

Oh and Duke deleted his post about the tyre conspiracy.. So now my posts don't make sense. Sorry

[norbs]

I bet norbs could even drive the cars now

Hey, I can drive all cars, just some better than others.

The 2 guys that I know that aren't on ARSE that play iRacing have 180 degree opinions of the updates. The one that used to race HQs and now has a Nismo something or other as a track day car loves this update. However, his iRating is way lower than the guy that hates the update.

I've said it a hundred times before, horses for courses. So many variances to consider, from equipment to what people want from a sim. It is just amplified because iRacing is huge compared to other sims, so there are more iTards.

[renesis37]

I was just seeing if you were still alive :P

Anyone who has driven a real car in anger or understands how a car drives at the limit will mostly appreciate the update in my opinion.

[Gizmo]

Hey guys! It's been so long since I've been on this part of the interwebs......

With my tax return I'd like to get some sim racing gear and get back into iRacing, I have kind of been missing it. Looking for some advice on Direct Drive Wheels, from what I have read they are so far beyond anything else. There's so many options though. Has anyone got one and mind sharing their thoughts/experiences?

[Duke]

Umm... So every car that got a tyre update in the recent build has now had further refinements to address the unrealistic low pressures that's caused so much discussion & dissension...
Also they have addressed tyre pick up and debris retention to make accumulation of dust and marbles reasonable with soft and sticky tires.

Release Notes for 2017 Season 2 Patch 1
SIM
- Fixed the iRacing installer program to correctly refer to the 64-bit iRacingService64.exe, instead of the 32-bit version that no longer exists.
- Fixed an issue where if the iRacing installation directory name contained spaces, the iRacingService might not start properly.

Controls
- Fixed a bug where the updated fast releasing parking assist brake aid was not releasing as it should.

Tires
- Reduced the ability of tires to pick up and retain debris to make accumulation of dust and marbles reasonable with soft and sticky tires.

Visual Effects
- Heat haze distortion effect has been updated.

Particles
- Opponent cars' particles should now roll better.
- Opponent cars will now emit less smoke when on wet surfaces.
- Adjusted dust cloud generation and scale.
- Smoke particles should now appear more prevalent on tires.

PopcornFX
- Fixed an issue where multiple fireworks playing in the same frame were not emitting multiple sounds.

Replay
- Fixed a bug that was preventing the Results page on the Replay screen from populating with the results from all the weekend's sessions when watching a replay that was loaded off disk.

Virtual Reality
- Fixed an issue where the new VR headset sound rotation option could not be turned back on using the in-sim UI.
- Fixed panning sound issues with replay cameras and virtual reality headsets.

CARS:
Aston Martin DBR9 GT1
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Audi R8 LMS GT3
- Baseline setups have been corrected.
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

BMW Z4 GT3
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Cadillac CTS-V Racecar
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Chevrolet Corvette C6.R GT1
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Chevrolet Corvette C7 Daytona Prototype
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Dallara DW12
- Season setups have been updated.

Ford GT
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Ford GT GT3
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Ford Mustang FR500S
- Slightly increased cure-based tire degradation.

Global Mazda MX-5 Cup
- Season setups have been updated.
- Slightly updated tire construction and compound.
- Slightly increased cure-based tire degradation.

HPD ARX-01c
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.
- Tire compound has been hardened for greater responsiveness and lower yaw at which we see peak grip.
- Fixed an issue where the tires would appear to protrude through the fenders.

Kia Optima
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Mazda MX-5 Cup circa 2015
- Slightly increased cure-based tire degradation.

Mazda MX-5 Roadster circa 2015
- Slightly increased cure-based tire degradation.

McLaren MP4-12C GT3
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Mercedes-AMG GT3
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

NASCAR Sprint Cup Chevrolet SS
- Fixed a bad license texture that was causing corruption on the front splitter and rear spoiler.

Pontiac Solstice
- Slightly increased cure-based tire degradation.

Porsche 911 GT3 Cup Car (991)
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Pro Mazda
- This vehicle has been converted to use PBR shaders.
- Default wheel color has been changed.

Riley MkXX Daytona Prototype
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Ruf RT 12R C-Spec
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

Ruf RT 12R Track
- Season setups have been updated.
- Greater tire degradation over long runs via cure-based degradation.
- Minimum cold tire pressures have been increased to ensure realistic operating pressures.

VW Jetta TDI Cup
- Slightly increased cure-based tire degradation.

[renesis37]

Hopefully it is a step forward. Sounds like they just limited the tyre pressures instead of actually changing the compound though, I wouldn't put it past them :P

Time will tell. Let me know how you go Duke

[Sarsippius]

That would be my assumption as well but the tyre degradation might have an impact on optimal pressures.

[Duke]

Um... Seems they have taken the simple & easier route with the patch. :notimpressed:

Not sure about degradation yet, but in the garage, you can't set an initial tire pressure any lower than: Front 138 kPa - Rear 134 kPa

The actual way the pressures work don't seem to have changed. Just the minimum setting limit has been increased so you can't start below a particular number.

[Duke]

Cool!!!

[Righteous]

Fark they get into the corner quick. That's going to be fun the first time.

I did like the comment from iRacing on the video.


Scrub: "Are trucks going to be able to be run on dirt? Or just the dirt models and sprint cars?"
iRacing: "all cars will be able to run on dirt, whether you will be able to complete a lap in them is another story!"

F1 on dirt anyone?

[NeilPearson]

Anyone want to race the Blancpain enduro at road atlanta tonight?
need a team to do a 3 hour race apparantly. otherwise get DQ.