45 replies to this topic

[mcmirande]

Hello everybody

I found in Axel Cookie's webpage that he published a "GPL Tire Pressure Bug Fix Patch" but I couldn't find some description of that patch.

I'm sorry if it was vastly discussed elsewhere... but... could me show where?

Thanks!! Marcos

[John Woods]

Where is it?

[ginetto]

You mean: Lee Bowden published a "GPL Tire Pressure Bug Fix Patch"  

[Stefan Roess]

ginetto, on Jan 13 2017 - 07:49 AM, said:

You mean: Lee Bowden published a "GPL Tire Pressure Bug Fix Patch"  

Here: https://gplmotorworks.gplworld.de/

[mcmirande]

ginetto, on Jan 13 2017 - 07:49 AM, said:

You mean: Lee Bowden published a "GPL Tire Pressure Bug Fix Patch"  

Oops. I'm sorry. I just discovered it in the Lee's webpage

Edited by mcmirande, Jan 13 2017 - 08:46 AM.

[mcmirande]

I found it!

Info is here: https://srmz.racesimcentral.net/inde...pic=11638&st=30

Thanks. Marcos

[mcmirande]

It's unclear to me, however, if the use of this patch would modify lap times. And, if so, if it would improve them or not...

Did somebody already test it?

Cheers.

[JMF]

The GT mod, Lola T70 at Mt. Panorama, Bathurst. Identical setups. 2:04.04 vs. 2:04.55.

If I were to guess, I'd say the patch has a little more grip and a little more rolling resistance.

I'm about .5 seconds faster without the patch. Without the patch, it sounds like I'm at a higher rpm at the end of the straights. I'm more likely to lose the rear of the car at Griffin's Bend (T2).

With the patch, I'm more consistent. Braking is easier. Braking is much easier at Murray's Corner (the last turn). I don't think I encountered the brake bug once using the patch. Without it, it's easy to lock the left front wheel at Forrest's Elbow (the last sharp turn before Conrod Straight) and Murray's Corner. With the patch I can brake late and still recover with a little loss in time. Without it, many of my late braking mistakes result in a crash or spin. I'm more likely to over heat the rear tires without the patch.

In The Cutting, I'm faster without the patch. I only need to gear down to 2nd and I can use the throttle to point the nose in for the sharpest bend. When I'm using the patch, the rear of the car doesn't slide as much and I need to gear down to 1st. In 2nd gear with the patch, the car wants to understeer into the banking.

At this point, I'd be faster in qualifying without the patch and probably faster in a race with the patch.

At some point, I'll try fine tuning my setup with the patch and without it. I noticed differences in the tire's temperatures. It's not just the corrected values from the patch but differences in temperatures across the tire, inside vs. outside temps. With the patch, my setup might be improved with some minor camber changes and shorter gearing. That might eliminate the differences in lap times.

This patch seems beneficial with the GTs. I'm not inducing the brake bug. I'm not sure it's eliminated it but it's a definite improvement.

I could easily get obsessed with the Lola at Bathurst, so I'll be testing this some more.

Edited by JMF, Jan 13 2017 - 05:22 PM.

[rcb]

I've been playing around with the patch ever since it was released with the can-am 66 mod and I'll second JMF's findings.  The handling tends to be more consistent over time but my absolute fastest lap times are unchanged.  The mod this will have the biggest impact on is the GT 67's just because of the big difference in optimal tire pressure (32psi) and the bug in the physics (24psi).  Look at your tire middle temps before and after the patch to see the effect.

[mcmirande]

Wow! Thanks for such a detailed comparisons!!

I'm wondering now if most of the differences in handling between the original GPL cars and those of the 1967x mod are not due to this patch applied by default to the latter. The differences you describe are rather similar to the ones I found between the different 1967 F1 cars.

But... I'll do better comparisons to test this hypothesis

Thanks again!! Marcos

[rcb]

Edit again:  Looking at the 1967x mod files, I don't think it includes the pressure fix.  The only mod released with this fix included (so far) is the 66 Can-Ams.

Edited by rcb, Jan 13 2017 - 07:05 PM.

[mcmirande]

Thanks again!

[Cookie]

Oups

Yes I recommended to use the patch in our Bathurst Lola T70 MK3 race

and I can totally confirm the experience of Greg

[Robert Fleurke]

The question is if this patch can be run undetected and giving an advantage at certain mods, like original 67s!?

I suppose not (since it's aimed at mods with higher ideal tirepressures!?), but I'd like a valid answer anyway

Edited by Robert Fleurke, Jan 14 2017 - 07:28 AM.

[ginetto]

It's not faster, it's different; very probably it's slower.
IMHO You can see it as a setup change; anyone can change setup without incurring in cheating, right?

[JMF]

I made minor camber adjustments and a shorter 5th gear to improve my setup while using the patch. 2:03.66 without the patch. 2:04.36 with the patch.

With the patch in the GT mod, the tire temps are almost even across the tire while trying to set the tire pressure at 32 psi when warm. As most know, to get 32 psi without the patch requires a higher temperature in the middle of the tire. I may be getting a higher tire pressure with the patch. When I finished a stint with the patch, 3 of 4 tires were at 33 psi whereas 1 of 4 tires was at 33 psi without the patch.

Rob, in the GTs I think you have an advantage without the patch. It's a little more difficult to drive but the difference in lap times is noticeable to me. I could improve my consistency without the patch by slowing down to the lap times I run with the patch. I think there's more room for improvement without the patch than with it, so my difference in lap times may be closer to 1 second per lap instead of .5 seconds. As for other car sets, I have no idea of the differences. I will check it at some point. I'd guess the patch might make the 71 Can Ams a little easier to drive.

[mcmirande]

ginetto, on Jan 14 2017 - 08:51 AM, said:

It's not faster, it's different; very probably it's slower.
IMHO You can see it as a setup change; anyone can change setup without incurring in cheating, right?

I thought the same... if differences are not great and the patch mostly would produce slower laps, it could be used safely.

[rcb]

JMF,  the can-am 71's shouldn't be affected at all by the patch.   Their optimal tire pressures are 24psi, which is the same as the bug (24psi).  Thinking about it, was the bug the reason that the 71CA team set the optimals to 24psi originally?

Edited by rcb, Jan 14 2017 - 10:20 AM.

[Lee200]

Robert Fleurke, on Jan 14 2017 - 07:21 AM, said:

The question is if this patch can be run undetected and giving an advantage at certain mods, like original 67s!?

I suppose not (since it's aimed at mods with higher ideal tirepressures!?), but I'd like a valid answer anyway

The patch's effect will mainly be seen for those cars that use optimum pressures greatly different from 24 psi.  For the '67 F1 cars which use 24 psi for the front and 26 psi for the rear, I doubt you'll see or feel any difference at all.

The '67 sports cars will certainly be affected as will the upcoming '55 F1 cars which use 40 psi as optimum.  Again, the patch does not affect the tire's grip at all; it merely adjusts the tire's stiffness and the associated slip curve shape a bit.

In all our previous tests, using the patch makes the cars a tiny bit slower instead of faster, but they are easier to control.

[MECH]

https://www.youtube....h?v=5_H-LY4Jb2M

 

Bekijk video op YouTube