Dirty Air and Slipstream

[interpunct]

Greetings! Recently I was watching a video about slipstream and dirty air and it dawned on me. GT has had slipstream since the first game but has dirty air ever been implemented *at all* during the series?

From what I understand dirty air is a phenomenon that happens specifically on corners where the wind being pushed away from the car in front of you slows you down and affects the downforce on your car. There is another side effect to dirty air which is that since the air is not cool, it's actually hot your car can start to overheat and the compound on the tires as well due to the lack of cool air which I also don't know if it affects at all in game .

I tried testing it out with some cars in GTS but I cannot get to a satisfying conclusion, I'm also not at the stage yet where I can buy the Formula 1 cars the game offers. Still does anyone know if this is a feature in the game?

 

[ScottPuss20]

I don't know if dirty air is simulated in GT Sport, but let me tell you an instance where it might have been acting upon my car. I was going into the first corner on Maggoire and I was following a car quite closely. This was in a Group 3 car, so downforce would cause an air disturbance to the car behind. The car in front hit the brakes at the right time, and I hit the brakes as well (exactly the same as the previous lap), but my car doesn't pull up as I expect it to and I run wide. It felt as if my front aero had actually lost airflow, hampering my ability to stop. That is the only occasion where I felt as though dirty air was acting upon my car.

 

[Shottah072]

Yes trailing another car definetely effects your downforce performance. This is especially noticeable under braking. Less grip from downforce reduction can also effect your tirewear but i dont think the game simulates overheating of the tyres.

 

[interpunct]

Yes trailing another car definetely effects your downforce performance. This is especially noticeable under braking. Less grip from downforce reduction can also effect your tirewear but i dont think the game simulates overheating of the tyres.

This explains why a lot of times in tracks I know like the back of my hand had so many issues when trying to overtake on corners. This is the first time learning about this. I always figured that abusing the slipstream on corners was the way to go as well. Been doing it for years. I never thought of it as a bad thing. I'm asuming its not a huge deal on cars that are not formulas or LMP's, correct?

 

[Shottah072]

This explains why a lot of times in tracks I know like the back of my hand had so many issues when trying to overtake on corners. This is the first time learning about this. I always figured that abusing the slipstream on corners was the way to go as well. Been doing it for years. I never thought of it as a bad thing. I'm asuming its not a huge deal on cars that are not formulas or LMP's, correct?

The more downforce dependent the cars the stronger this effect will be. But even Gr3 and Gr4 cars will be effected. Also more noticeable trough high speed corners then low speed corners, downforce grip at high speed vs mechanical grip at low speed. And like i said less braking performance.

 

[Brzlav]

I usually notice more understeer in fast corners in dirty air in GTS, which is realistic as you are loosing downforce at the front. I think it is quite noticable in GT3 cars. Haven't tried but I guess you will experience that even more in the Gr. 2 cars.

 

[Vegard]

This was in a Group 3 car, so downforce would cause an air disturbance to the car behind. The car in front hit the brakes at the right time, and I hit the brakes as well (exactly the same as the previous lap), but my car doesn't pull up as I expect it to and I run wide. It felt as if my front aero had actually lost airflow, hampering my ability to stop.

That could be the consequence of the extra speed you had after drafting down the start finish though.

I haven't noticed any loss of downforce following closely behind other cars, but then again I haven't raced very much with high downforce cars.

 

[inri]

braking distances are increased by maybe 5%, you must brake earlier if you are following someone and this is what probably causes a lot of turn 1 accidents in sport mode. during the actual cornering there isn't too much of a difference in gt sport

 

[mthomas_95]

It's definitely there, Gr3 and above you feel it in the high speed corners. The esses through the middle sector at Dragon Trail is a common place to experience it and the second part of the bus stop chicane becomes trickier to judge.

Tyre temperature is simulated as well, just not that well communicated through the HUD. The first sector at Suzuka I find shows it. Towards the end you can feel and hear the tyres start to struggle after the sustained cornering loads if you're not careful enough. Racing hards also have less grip in the early/late time slots, the fastest times in Sport Mode are consistently a few tenths slower than midday timeslots.

 

[Ryan Sandall]

I’m not sure if there is dirty air tbh, I think there is just slipstream and the reason you are running wide under braking and wide following a car mid turn maybe because slipstream is pulling you a bit faster bringing you closer to the limit during the turn, and the braking is cos your entering faster because of slipstream and bearing in mind your slipstreaming while your braking until the speed is low enough to not affect your car.
I always try to brake out of the slipstream or slightly to one side to avoid this and hitting the other car incase I need to move to one side

 

[Alpha Cipher]

I’m not sure if there is dirty air tbh, I think there is just slipstream and the reason you are running wide under braking and wide following a car mid turn maybe because slipstream is pulling you a bit faster bringing you closer to the limit during the turn, and the braking is cos your entering faster because of slipstream and bearing in mind your slipstreaming while your braking until the speed is low enough to not affect your car.
I always try to brake out of the slipstream or slightly to one side to avoid this and hitting the other car incase I need to move to one side

That was my first impressions when I wash wide, but I've encountered every situation @mthomas_95 pointed out, and I'm pretty sure there's dirty air
There's no other reason as well why my apex speeds are slower than without slipstream

 

[interpunct]

It's definitely there, Gr3 and above you feel it in the high speed corners. The esses through the middle sector at Dragon Trail is a common place to experience it and the second part of the bus stop chicane becomes trickier to judge.

Tyre temperature is simulated as well, just not that well communicated through the HUD. The first sector at Suzuka I find shows it. Towards the end you can feel and hear the tyres start to struggle after the sustained cornering loads if you're not careful enough. Racing hards also have less grip in the early/late time slots, the fastest times in Sport Mode are consistently a few tenths slower than midday timeslots.

Interesting. All of these are factors I might take into account specially the warming of the tires. I've been having issues on mission mode with the 30 lap endurance where I lost at the last second thanks to a Ferrari that overtook me out of nowhere with 6 seconds on top of mine and only now am I learning about all of this. Been playing GT since the first one but I've never been one to really strategize my pitting and stuff like that. I've always put racing hards and use them as much as I can till I can't anymore lol.

Knowing how to make my tires last more and stuff like this will certainly by help me up my game a bit when I eventually buy PS+ to play online.

 

[DaigoD]

Racing hards also have less grip in the early/late time slots, the fastest times in Sport Mode are consistently a few tenths slower than midday timeslots.

Are you serious? I have never even thought about this. Does this apply to time trials too? If so, then my car comparison tests just became a lot less meaningful because I always chose a random time.

 

[Lord Protector]

Of course it's simulated. Even braking is less effective when slipstreaming a car.

 

[Alpha Cipher]

Are you serious? I have never even thought about this. Does this apply to time trials too? If so, then my car comparison tests just became a lot less meaningful because I always chose a random time.

I wouldn't bite that. My assumption is that the times are different because of visibility- ie. at noon everything is visible, no shadows to block any potential markers

 

[DaigoD]

I wouldn't bite that. My assumption is that the times are different because of visibility- ie. at noon everything is visible, no shadows to block any potential markers

Ok, thank you. If it really were true I think there would be a discussion going on about it somewhere. I did a quick search and found nothing.

 

[dfspires]

It's definitely there, Gr3 and above you feel it in the high speed corners. The esses through the middle sector at Dragon Trail is a common place to experience it and the second part of the bus stop chicane becomes trickier to judge.

Tyre temperature is simulated as well, just not that well communicated through the HUD. The first sector at Suzuka I find shows it. Towards the end you can feel and hear the tyres start to struggle after the sustained cornering loads if you're not careful enough. Racing hards also have less grip in the early/late time slots, the fastest times in Sport Mode are consistently a few tenths slower than midday timeslots.

I often forget to handle tyre temperature, they let you know they are overheating when you lose traction with the red square around the wheels on the hood, which is useless because you know because you are spinning out of control.

I understand that a lot of cars don't have sensors and therefore one can argue the simulation should not mimic it.

But come on, it is a racing game, they could at least have some tutorial or challenges to teach that, especially because each car will have it's peculiar way of how the tyre temperature behave.

 

[BileRizer]

Glad I found this. Languishing as D-DR for ages, finally cracked C, only to return to bottom of D this w/end with spate of terrible results. These often came from corners behind someone else where I'd swear I just randomly spun when hadn't before (slipstream braking and throttle control should have been ok). I've been watching a YouTuber recently and he talks quite a bit about it and you can see it manifest in his high level races too. Maybe the key then is to be ready for loss of traction in these circumstances or avoid slipstreaming in certain corners - harder than it sounds.

 

[Sidawg2]

In last weeks GR2 Autopolis races you could feel it. You'd get within about 0.8 of the car ahead and that's where you'd stay unless somebody made a mistake.

 

[BileRizer]

Hi Sidawg2. From what I've watched, Autopolis is a beast for it. I copped dirty air unsettling during FIA on Saturday, and then again for 3 Daily Races straight at Interlaggos - at race start, and then whenever I caught up with someone. Frustrating, but a good lesson for this relative noob.

 

[GT_Alex74]

Dirty air becomes really obvious in Gr.2 cars, it kicks in when you get 0.6 - 0.8s behind another car. It's at least as bad as with Gr.1 cars, I'd even say a bit worse. But so far my biggest dirty air experience was with the F1500-TA, coming towards the esses on Seaside II a full second behind someone else felt like my front wing was completely missing.

I wouldn't bite that. My assumption is that the times are different because of visibility- ie. at noon everything is visible, no shadows to block any potential markers

Track temperature is definitely different between the different weather options, which is definitively felt in grip levels. And it's not always the brightest option that is the fastest, in fact, during Barcelona's IGTL 3h, I practiced a lot on qualy and 1st stint's weather (classic afternoon weather), and finally did 2nd stint instead (dusk weather slot), and the track instantly felt a bit faster.

 

[gtpierre]

Dirty air becomes really obvious in Gr.2 cars, it kicks in when you get 0.6 - 0.8s behind another car. It's at least as bad as with Gr.1 cars, I'd even say a bit worse. But so far my biggest dirty air experience was with the F1500-TA, coming towards the esses on Seaside II a full second behind someone else felt like my front wing was completely missing.

Track temperature is definitely different between the different weather options, which is definitively felt in grip levels. And it's not always the brightest option that is the fastest, in fact, during Barcelona's IGTL 3h, I practiced a lot on qualy and 1st stint's weather (classic afternoon weather), and finally did 2nd stint instead (dusk weather slot), and the track instantly felt a bit faster.

With any fast car, one should be able to notice that braking behind someone is less efficient than braking when you are in front of someone or alone. With all cars with important aero, one should be able to notice an "understeer like feeling" in high speed curves when following someone.

I agree that track conditions change grip. Morning and foggy conditions can almost "feel" like it's a bit wet.

What I'm still unsure is whether braking is affected by where on the track you brake (racing line should brake better than the dirty part of the track). So far I would say no

 

[WaikeCU]

I noticed during the 1h race by TSR at the Nordschleife 24h layout I was following the car ahead closely at Galgenkopf, but my car understeered on to the grass and into the barrier. So I believe aero is affected by the car ahead.

 

[Daz555]

I think there is an effect going on here but it is relatively simple in terms of simulation. I get the impression there is a loss of grip on the front when you are running a downforce car close to one in front but I'm not sure overall about the complexity of that dirty air. In Project Cars 2 for example you can really feel the loss of grip (aero push) when following closely and also feel a loss of grip (aero loose) when someone is close behind or tight on your inside and disrupts the air on your car. When you add more cars to each side it gets more complicated.

So there is something going on in GTS I'm fairly sure but nothing overly complex. It would be great to hear the official lines on this question.