PC - PC Tier 5 Round 9 - Sugo GP - 15.08.18 @8pm UK time | ApexOnlineRacing.com

PC PC Tier 5 Round 9 - Sugo GP - 15.08.18 @8pm UK time


Stephan

AOR iRacing GTE S3 AM Champion & Former S-Mod
Premium Member
Oct 19, 2016
8,122
5,208
Did maybe 20 laps total now, of that 15 in one stint. those 15 laps ate half my front left, so might actually have to get tires, let's see.
Even in rain, I had more grip than at Brno :p
Did consistent 29s, within .3s each. did one 1:27.7 with a full tank, but couldn't replicate it.
 

CarbonUK

AOR iRacing GTE Season 6 AM Champion
Premium Member
Sep 23, 2017
251
157
Did maybe 20 laps total now, of that 15 in one stint. those 15 laps ate half my front left, so might actually have to get tires, let's see.
Even in rain, I had more grip than at Brno :p
Did consistent 29s, within .3s each. did one 1:27.7 with a full tank, but couldn't replicate it.
Was the tyre wear from locking the brakes?
 

CarbonUK

AOR iRacing GTE Season 6 AM Champion
Premium Member
Sep 23, 2017
251
157
Shouldn’t- with ABS on
I think you can still lock the brakes even with abs on. Next time do a test in the rain byy slamming your brakes and come to stand still and watch the tyres you should see a Chuck of the tyre wear disappearing . I noticed this practicing at rapuna
 

Gwegwyn

Formula 3 1st Driver
Mar 13, 2017
296
186
@CarbonUK @Stephan A good solution to have the brakes not locking up is to lower the brake pressure. Yes, that means you have less pressure on the brake disk when applying full brakes, but it should also mean less lockup = less tire wear. In the rain you can't ues the same amount of pressure. You guys probably already knew this, but I still found it worth mentioning.
 
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poisike78

AOR PCars PC Ginetta GT5 S1 T2 Champion
Feb 28, 2018
2,177
1,023
If the excessive tire wear is from brakes, shouldn't it affect left and right side evenly? I only get it on the left side, so I think it's the last corner.
 
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Stephan

AOR iRacing GTE S3 AM Champion & Former S-Mod
Premium Member
Oct 19, 2016
8,122
5,208
I think it’s a bit of both. Will see in practice tomorrow. Will have 2 strategies ready: 1L and new tires
 

MTN

Premium Member
Premium Member
Jun 2, 2018
41
32
qualy will be crucial here i think, very hard to make a pass, gonna be tricky with the backmarkers too, very narrow track!
 

Gwegwyn

Formula 3 1st Driver
Mar 13, 2017
296
186
If the excessive tire wear is from brakes, shouldn't it affect left and right side evenly?
The short answer is both yes and no. When you are driving on a straight road, with no imperfections in the roadsurface and both tires at the same pressure and temperature, braking would affect both tires evenly. But as soon as there is a corner where you brake, uneven roadsurface or different tire pressures, the tires will wear differently.

The long(er) answer:
Basically, what it comes down to is the maximum grip a tire has/can provide. You could visualize this by making a "G-Force"-graph for your tires. When the moving dot is in the middle, all forces on the tire are equal. You can then draw a prefect circle around the center, which is the maximum grip a tire has (i.e.: the maximum force that can be applied to the tire without the tire slipping/losing grip). When the dot moves to the bottom of the graph, the car is accelerating. When the dot is moving to the side, the car is turning to the opposite side.

The tires are used for cornering, accelerating and stopping the car. Sure, the engine produces the power, but the tires transfer the power of the engine to the track, which results in the car accelerating (or moving at constant speed). And yes, the brakes produce the friction (force) necessary to stop the car, but this force is also transfered through the tires to the track. And the steeringwheel makes the fronttires turn, but it is the lateral grip of a tire that makes the car go around a corner.

Whenever there is more force transfered through the tires than there is grip (adhesion) in the tires, the tires lose grip and will slip. A normal street car has most of the time an engine that is not powerful enough to produce more force than the tires can transfer to the street. So there is no wheelspin. A GT3 car has a more powerful engine, which in turn needs better tires. With a GT3 car in 1st gear and full throttle, there will likely be wheelspin. We can visualize this by going back to the G-Force-graph. The force from the enige makes the car accelerate. However, the force produced by the engine is great than the maximum force the tires can transfer to the asphalt, which means the wheel spins. This results in waste of power, slower acceleration and thus losing time. TCS is there to help, but all it does is limiting the engine so there is less wheelspin. Some people are faster with TCS on, some are faster with TCS off. I always race with TCS off, no matter the weather.

When a car turns around a corner, the same rules aply. One cannot go around a left hairpin with 200 km/h. There is more force needed to turn the car with that speed around that corner than the front tires can provide, resulting in understeer. Most racers want to accelerate as soon as possible when exiting a corner. Howerever, when too much throttle is applied when exiting the left hairpin, the dot on the graph moves to the bottomright exceeding the "circle of grip". The rearwheel(s) have to transfer more force to the track then possible, resulting in oversteer.

When braking the same rules apply once more. Too much brakingforce results in the tires locking up (the force exceeds the "circle of grip"), reducing the effectiveness of braking. Ofcourse there is ABS, but all that does is locking and unlocking the brakes like a strobe light. It does not make your car brake harder. When braking while turing, the front and rear tires have to cope with both the lateral forces to make the car turn AND the braking force to slow the car down (front tires moreso than rear tires). Then there is also the effect of weight transfer, which makes the tires on the outside of the corner work harder than the inside tires. This results in uneven workload on tires, thus resulting in different tire wear.

Sugo is a track with lost of stop and go corners and the long sweeping corner at the end of the lap. Therefore the left tires have more work to do, which already results in more tire wear on the left. Couple this with trailbraking and the left tires have even more work to do and probably lock up in the rain. Meanwhile, the right tires have less work to do and probably do not lock up when in a corner.

So to answer your question: it is possible to have both tires wear evenly due to braking, but that is not nearly always the case. To prevent locking up the tires: use lower brake pressures (I am not a fan of simply using higher ABS, since the tires still lock up, albeit in very, very short bursts). This probably also helps with wear due to braking.

Sorry for the long read; I got a bit carried away =P I'll see if I can make some "G-Force-graphs" to visualize the stuff I explained above and make it more readable.
 

Happyal27

AOR PC GT3 S11 Tier 4 Champion
Feb 24, 2018
225
148
Back from my holiday :) ran some laps while the wife was out and from the lap times posted here, and watching Voodoo, I'm slow here so far.

Worst than being slow is my tires are being eaten too, I need more practice to see if I can get faster, and I might try that pc2tuner tool that Voodoo uses, see I can make any sense of it.
 
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Gav88888

Formula 3 Test Driver
Apr 6, 2018
191
92
My front left was being eaten alive and would only do half race distance, player around with things and it seems to degrade slower now but still doubt it will last the race so likely change of tires midrace.
 

VoodooChild

Assetto Corsa Coordinator
Staff member
AC Coordinator
Mar 27, 2018
1,094
899
if you have a big difference on weariness between left and right side it means your car has a lot of body roll.
Body roll is not necessarely a bad thing, because a softer car has more grip than a stiff one, but it starts being a problem when tyres overheat and/or wear in an uneven way.
To fix that, you'll need to stiffen up your anti roll bars so the car will roll less, and the load will be more evenly spread on the two sides.
A stiffer car will be more reactive but will be more keen to slide on hard corners, which will induce understeer, so it's important that you find just about the right amount of stiffness to save your tyres while not compromising your grip.
 

Aarup

Semi-Pro Karter
Nov 20, 2017
19
4
I'm not sure I'll be able to take part in the race - the wife's out of the house that evening so I'm looking after the kids, but it varies how easy they are to keep in bed while i race :)
 

Gav88888

Formula 3 Test Driver
Apr 6, 2018
191
92
Front ARB is nice and stiff to combat understeer but happy with the setup, getting some 1:27’s but mainly 1:28’s. Suspect it will be eventful so a front tire change won’t be too much of an issue.
 

Lindholdt

Premium Member
Premium Member
Apr 26, 2018
319
298
A stiffer car will be more reactive but will be more keen to slide on hard corners, which will induce understeer, so it's important that you find just about the right amount of stiffness to save your tyres while not compromising your grip.
Easier said than done in some cases :D J/K
It's really nice that you share your knowledge about these things @VoodooChild, helps a noob like me to improve my setups and get better pace. Those tips you gave me on Discord the other day for the Ford helped a lot, especially the diff changes made a big difference for me (y)
 
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Gav88888

Formula 3 Test Driver
Apr 6, 2018
191
92
Did anyone participate in the practice race this evening? Did the tires last the race distance?
 

Stephan

AOR iRacing GTE S3 AM Champion & Former S-Mod
Premium Member
Oct 19, 2016
8,122
5,208
Did anyone participate in the practice race this evening? Did the tires last the race distance?
tires lasted, but got a bit more slippery in the end.
I'm useless in the rain. pace was good, but was spinning as usual in the rain
 
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Happyal27

AOR PC GT3 S11 Tier 4 Champion
Feb 24, 2018
225
148
Fun race for me, I was surprised by my pace in Quali because that came out of no where.

Race was different, and much more like I expected. I was more or less a rolling chicane at some points in the race. But I did OK (or me) and didn't bin it, so I'd be happy if I can do the same in the real race.

As for tires, mine did last the race, but the last handful of laps I was struggling, I lost a lot of grip in those laps.
 
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