BMW M3 GT4 setup enquiry

[cpcdem]

Ok, do you know anything about Zhuhai? He is in the high 80s, could he possibly use Soft tires?

I am not sure, do GT4 cars have soft tires? I will check later tonight, but high 80s (in C) I think are still fine for hard tires. At least for GT3 cars that I used some time ago, only below 80C hard tires were losing their grip. And soft tires at > 95C.

If I understood correctly the biggest problem of the OP is the overheating brakes, >500C before the braking point, with Zunhai's heavy braking zones probably means 800C or more max while braking, which make brakes to fail. Just completely open the brake ducts, there's no point closing them down, only in ovals you can see a small speed difference with them closed.

[blinkngone]

I am not sure, do GT4 cars have soft tires? I will check later tonight, but high 80s (in C) I think are still fine for hard tires. At least for GT3 cars that I used some time ago, only below 80C hard tires were losing their grip. And soft tires at > 95C.

If I understood correctly the biggest problem of the OP is the overheating brakes, >500C before the braking point, with Zunhai's heavy braking zones probably means 800C or more max while braking, which make brakes to fail. Just completely open the brake ducts, there's no point closing them down, only in ovals you can see a small speed difference with them closed.

GT4 Softs


Turn 1 isn't really a hard braking zone, just early brake to scrub off some speed, maybe medium hard. Turn 7 through 12 2 Hard braking zones(7/11) and 1 medium Hard, turn 9. 500C is about half way to the mid point for cast iron brake temperature. Brief spikes over 850 C(https://www.youtube.com/watch?v=nfZNdzi3J10) aren't really a problem as long as there is enough distance to cool back down before the next zone. Even with the ducts closed to 10% I didn't see much above 800 C. I think the OP makes long runs(10 laps), not TT so his brake temps average of 500 C over a long run seems ok.

Hey, you know I can't drive any more but, I switched to Soft tires and improved a bit. Well, ok, the 1st lap I made I just was doing brake checks with Hard tires(1:50.020 +0:09.922). The 2nd lap I ran with Hard tires was to get familiar with the track, picked up 2+ seconds. Then I rested up and switched to Soft tires and ran a lap, maybe I am more familiar with the car/track now because with each run I improve but I think Softs are worth a try anyway. I am a tester now and not a racer.

I can get ahead of 4th through turn 9 entry/exit but by then my arm and legs are about done in. Turn 10 with this car needs some braking. I would say turn 4 is better with late hard braking using the BMW as well.

[warhammer2]

Last night I did another few stints of ZIC with the M3 GT4. Soft tires. First 5 laps felt.faster than hard slicks, can carry more speed into corners. Temp is around 33oC ambient.
From lap 6 onwards i start to feel the brakes and tire problems, so less grip and have to brake earlier to make the apex. Tire temps max 103 but some corners (fronts ?) around 93 oC.
So i was doing consistent 1min 43s prior to the fade off and then started to get caught up by AI from behind. I did a few stints where I was leading or in top 3 then I would.make mistakes as the braking point and tires fade.
Brake.ducts set at 74 / 55 and brake temps are fine.
I think the tires are giving the problems.

[blinkngone]

Last night I did another few stints of ZIC with the M3 GT4. Soft tires. First 5 laps felt.faster than hard slicks, can carry more speed into corners. Temp is around 33oC ambient.
From lap 6 onwards i start to feel the brakes and tire problems, so less grip and have to brake earlier to make the apex. Tire temps max 103 but some corners (fronts ?) around 93 oC.
So i was doing consistent 1min 43s prior to the fade off and then started to get caught up by AI from behind. I did a few stints where I was leading or in top 3 then I would.make mistakes as the braking point and tires fade.
Brake.ducts set at 74 / 55 and brake temps are fine.
I think the tires are giving the problems.

Ok, sorry about that. I guess Hard tires it is then. 1:43s is pretty quick compared to PC TT runs, would put you in 4th. I could possibly manage a 1:44s on the outlap, I am at 1: 45s now. So are you going to adjust the AI? If they are overtaking it would seem their Skill needs to be lowered. Are the BMWs overtaking or the Cayman and Ginettas? These cars are 2 seconds a lap quicker on average than the BMWs in TT on PC. The only driver we have a direct comparison with is godcza running Default, Cayman he is at 1:41.636 +0:01.017 and with the BMW he is at 1:44.367 +0:04.269, Ginetta he is at 1:43.239 +0:02.594 and Aston Martin 1:42.416 +0:01.456.

In Time Trial on PC our Ambient is only 22.78 C.

Ok, I set up a Hot track in Custom race Using Hard tires. Too many laps for me to run though, no arm and legs left especially since I spun on my second lap and had to run the 3rd. About the same time as I ran with Softs on cold track. Forgot to open radiator.


Ok, I hate doing this but I ran my best time. So yeah 1:43s with Hards seems reasonable.

This time I lost it at turn 9 so again can't get a clean lap to start my run at a good time, used standing Start. At least I opened my radiator. Used your Brake Ducts, used heathen's setup and tire pressures. I am easing on the brakes at Mr. Scribbles White line instead of hard braking later. Changed my mind about 4, braking earlier instead of late hard so I have more control and get a better racing line. Haven't figured out the last corner except too inside apex is very bad, outside to the rumble strips better.

[warhammer2]

Ok, sorry about that. I guess Hard tires it is then. 1:43s is pretty quick compared to PC TT runs, would put you in 4th. I could possibly manage a 1:44s on the outlap, I am at 1: 45s now. So are you going to adjust the AI? If they are overtaking it would seem their Skill needs to be lowered. Are the BMWs overtaking or the Cayman and Ginettas? These cars are 2 seconds a lap quicker on average than the BMWs in TT on PC. The only driver we have a direct comparison with is godcza running Default, Cayman he is at 1:41.636 +0:01.017 and with the BMW he is at 1:44.367 +0:04.269, Ginetta he is at 1:43.239 +0:02.594 and Aston Martin 1:42.416 +0:01.456.

In Time Trial on PC our Ambient is only 22.78 C.

Ok, I set up a Hot track in Custom race Using Hard tires. Too many laps for me to run though, no arm and legs left especially since I spun on my second lap and had to run the 3rd. About the same time as I ran with Softs on cold track. Forgot to open radiator.


Ok, I hate doing this but I ran my best time. So yeah 1:43s with Hards seems reasonable.

This time I lost it at turn 9 so again can't get a clean lap to start my run at a good time, used standing Start. At least I opened my radiator. Used your Brake Ducts, used heathen's setup and tire pressures. I am easing on the brakes at Mr. Scribbles White line instead of hard braking later. Changed my mind about 4, braking earlier instead of late hard so I have more control and get a better racing line. Haven't figured out the last corner except too inside apex is very bad, outside to the rumble strips better.

Thanks for trying out the setup. On softs my time is ~1:43.3 but i am no where near good. AI at 80 only. on hard slicks i think i run 1:44-45 consistently. I can catchup easily when the tires and brakes are in good shape and operating normally (usually first 5laps ). And often i lost it when fighting for P1, trying to overtake on the inside but we touch or i simply overshoot or spin off when the tires lose grip.

Last night i did a race from the back of the grid p16, soft slicks and finished 5th， would have been 3rd if not.for spinning out at lap 7. Brakes are around ~470oc on all corners with 75/55 ducts. Radiator 40%.

[blinkngone]

Hi, AI at 80 what? What is the Skill and what is the Aggression setting? What cars are you up against for the lead? Are you using "Same Class" or "Identical"?

The settings heathen used are for the cold track we have in TT. Can you tell if the front end grip is wearing out too quickly? Or just overall f/rear? Maybe you can ease off on the camber a bit. Well c**p! I just noticed heathen used -3.6 on left front and -3.3 right, he really is a "heathen". Same for rear camber, offset. What camber settings did you use?

If you used heathen's camber settings try moving the left side camber lower to match the right side front and rear. See if the tires last longer.

Here is heathen's Suspension page from Dubai, a track hotter than you are running. His Zhuhai suspension was different because he was trying to cope with the cold track temperatures we have in TT at Zhuhai. So using the lower right side camber adjustment could help. If you think you are better off on Soft tires instead of Hards you could also try his Dubai camber settings.

[warhammer2]

Hi, AI at 80 what? What is the Skill and what is the Aggression setting? What cars are you up against for the lead? Are you using "Same Class" or "Identical"?

The settings heathen used are for the cold track we have in TT. Can you tell if the front end grip is wearing out too quickly? Or just overall f/rear? Maybe you can ease off on the camber a bit. Well c**p! I just noticed heathen used -3.6 on left front and -3.3 right, he really is a "heathen". Same for rear camber, offset. What camber settings did you use?

If you used heathen's camber settings try moving the left side camber lower to match the right side front and rear. See if the tires last longer.

Here is heathen's Suspension page from Dubai, a track hotter than you are running. His Zhuhai suspension was different because he was trying to cope with the cold track temperatures we have in TT at Zhuhai. So using the lower right side camber adjustment could help. If you think you are better off on Soft tires instead of Hards you could also try his Dubai camber settings.

AL skill 80, aggression 65. Same class 16 cars starting from the back.
I think i.might be overheating the softs. Yorkie's youtube tuitorial suggest 70-95 oC but i was around 103 on the rears last night. Fronts are around 93oc.
May switch back to hard slicks and adjust brake bias more to the front to reduce rear tire temps.

[blinkngone]

Hey, I have run against the BMW in a couple of Custom Races and for some reason it is the quickest car of the GT4s. Only car that challenges me. Is that what you are finding? Surprised me, I was in the Cayman. It's always that same Gray or Blue/Black one.

[warhammer2]

Hey, I have run against the BMW in a couple of Custom Races and for some reason it is the quickest car of the GT4s. Only car that challenges me. Is that what you are finding? Surprised me, I was in the Cayman. It's always that same Gray or Blue/Black one.

i usually find the xbow, bmw at the front.. ginetta and cayman in the middle and 86, mustangs at the back. The xbow are fast in corners but slow on the straights, cayman i find are more balanced (for AI).
Mustangs are slowest in corners

[blinkngone]

Hey, sorry I can't run many laps. Just to get an idea I ran the hards, I tried to put in a decent lap on lap 4. Increased toe to -0.4 front and 0.7 rear. Did not adjust tire pressure. Forgot radiator again, damaged turn 1 melee. I have tire wear at Authentic, doesn't look bad to me. Didn't push much so I think you could be faster.


Your brake ducts look good.