BMW M1 Physics

Sorry Alberto im out for the next 2 nights so will try later in the week
good job mate ... Jukka THX for the Help

I'll have a go with it at Monaco later this evening (perharps this time my feet will be in the right pedals) right Carl?????

I'll do some laps at the Osterreichring , Zolder and Dijon later tonight

Ok, I managed to get some spare time and did some laps at Monaco.

I did 11 laps and my best time was 1:36.628 against 1:34.073 earlier this year on race trim (52L)

The engine now is superb, it feels like a high reving engine. The brake distance is much higher, much better and the handling tends to understeer (again very good) with a snap oversteer when you try to gas it out of the corners. And when braking if you don't blip when downshifting you get a mild oversteer entering the corner. final, you now can notice the weight of the car on acceleration, specially braking, and on the corners... doesn't feel artificial.

Conclusion: so far the car feels really great, I cannot tell anything about the time because I don't know the real time at Monaco, but it definitely looks on the right path

Tiago Malafaya wrote:

I cannot tell anything about the time because I don't know the real time at Monaco, but it definitely looks on the right path

Fastest Lap: Hans-Joachim Stuck 3. 1:41,680

Thanks Carlo

So still 5 sec, and I'm not the best at Monaco for sure, so we're probably talking of at least 6 sec.

Tiago Malafaya wrote:

Thanks Carlo

So still 5 sec, and I'm not the best at Monaco for sure, so we're probably talking of at least 6 sec.

Nearly the same at the Osterreichring, i'm still 8 secs faster than the 1980 lap record (1.46.4 - 1.54.2)

But i'm 6s slower than my PB (1.40.6 i think it was)

As for the physics, i agree on what Tiago said

Zolder: 7s difference (1.32.4 - 1.39.1)

Dont focus too much on laptimes, the tracks (especially old converted tracks like GPC79's) could be really inaccurate and there are other variables that could influence laptimes we can't recreate with the game (like weather or grip level of the track). I'd say a gap of around +- 3 seconds would be a good achievement.
Donington GTL is quite accurate tho, it should be a good point of reference.

As Jukka mentioned before, there's a bug in the left rear brake:

I just did some quick math with the lap times you have achieved, and interestingly in three circuits the difference was the same 7%. In two others it was somewhere between 5% and 6%

Quote :

Dont focus too much on laptimes, the tracks (especially old converted tracks like GPC79's) could be really inaccurate and there are other variables that could influence laptimes we can't recreate with the game (like weather or grip level of the track). I'd say a gap of around +- 3 seconds would be a good achievement.

Yes, that I figured too. However, since lap times seem to be on average some 6% quicker, I think we can asume as a fair tweak to make the car that much slower. Since the engine and suspension feel all right, I'll only tweak two areas:

-Aero: More body drag, not adding grip
-Tyres: This area was yet untouched, so I will reduce tyre grip

The first one will be more noticeable at Hockenheim and Osterreichring, the second at Monaco, Donington, etc.

The good thing is that now I can compare well my lap times with yours, and so I can precisely tone down grip until I get the laptimes I want for me, which should translate into the proper ones once you guys drive.

Quote :

As Jukka mentioned before, there's a bug in the left rear brake:

Found the bug and solved

Alberto Ibañez wrote:

Quote :

As Jukka mentioned before, there's a bug in the left rear brake:

Found the bug and solved

Yeah, noticed that too, but didn't bother with it since it was already referenced

I agree with reducing tyre grip a bit, All areas should be tweaked.

And I agree with Gui of course, my target as always is GP79 where when we are faster than real life it's always around the 2-3 sec margin. That should be the objective

Guillaume Siebert wrote:

Donington GTL is quite accurate tho, it should be a good point of reference.

Is it the same track we used in the Procar and F179 race?

New version is up:

http://www.mediafire.com/?kja46j1c84g1y84

This one includes now:

-Brake bug fix
-New tyres taken from the GTL Pantera. Since they are exactly the same size as the M1 ones (But one inch less in rim diameter) it's safe to asume they provide the proper grip. Warm them up well first!
Note: The new tyres will shorten gears a bit, but since in my testing the car did not reach top speed at Hockenheim, and the engine felt more lively, I decided to leave it like that. If you reach rev cut, tell me so and I will again make ratios a bit longer.


Still to do:

-Check engine temperature (water & oil) in longer runs
-Check tyre wear in longer runs

Ive just managed to do a few laps at Hockenhiem
i wont tell you what my laptimes are as its a little embarrasing

The car feels really nice to drive power delivery is good and im fine with the brakes
but im suffering with understeer at Hockenhiem and top speed for me is 175mph
which i would say is a little on the slow side ....

Im using the JP(hso) Hockenhiem track version which i think is a much more accurate
representation of the track i need to learn to drive the car again as it feels so different ...

Are you sure there was no adjustment on that huge great wing ....

Tiago Malafaya wrote:

I'll have a go with it at Monaco later this evening (perharps this time my feet will be in the right pedals) right Carl?????

Webbed feet can be such a pain

Hi alberto and welcome will try the new files at monaco asap

Did 20 consecutive laps at Zolder

In terms of laptimes we're very close to the 1979 ones, in fact my fastest lap (with 50L of fuel and default setup) is a 1.38.9 vs 1.39.1 in 1979

I took 2 complete laps to warm up the tyres, especially in the first one the car was very slippery and had no grip.
The tyre wear is minimum, in fact i did 1.39.x for nearly all the laps, none of the tyres suffered overheating (max temp 95 degrees in the left rear, the right front was 75° only)
The left rear brake has still that weird temp of -2 billion degrees

Doh...somehow an old file slipped into the release and the brak bug fix was not added.

Updated files (No other changes except brake bug fix): http://www.mediafire.com/?jis4bbvkgjlpif9

Quote :

im suffering with understeer at Hockenhiem

It should understeer wildly on cold tyres, and you need at least two laps to heat them up. I can make the car more neutral ar corner entry by lowering the diff coast lock, but I think the car behaves more or less correctly.

Quote :

top speed for me is 175mph
which i would say is a little on the slow side ....

I also thought the same at first, but since the car doesn't have huge grip in cornering anymore, and the brakes are less powerful, lap times should be still faster than real if the top speed was higher. Raising top speed would mean having to slow down the car in corners, and that would produce unrealistic lap times in slower tracks. So it's definately the correct high speed to be reached.

Quote :

Are you sure there was no adjustment on that huge great wing

Not AFAIK. The wing was introduced after some pre-season testing in Osterreichring revealed that the car's rear was unstable at high speeds, but I haven't seen any reference to it being adjustable, nor does it seem like that when looking at pictures.

Quote :

id 20 consecutive laps at Zolder

In terms of laptimes we're very close to the 1979 ones, in fact my fastest lap (with 50L of fuel and default setup) is a 1.38.9 vs 1.39.1 in 1979

I took 2 complete laps to warm up the tyres, especially in the first one the car was very slippery and had no grip.
The tyre wear is minimum, in fact i did 1.39.x for nearly all the laps, none of the tyres suffered overheating (max temp 95 degrees in the left rear, the right front was 75° only)

Looks like we are getting closer now

If you feel tyres should have some more wear or heat up quicker, I can try to fix that.

Tried a couple of laps at Zolder and I think that the front tyres could have a little more heat on them, not quicker, more because I did 15 or so laps and the front tyres never passed the 70º's mark and that's a little cold in my opinion.

Other than that I think it's pretty much there, driving is so much rewarding

Tiago Malafaya wrote:

Tried a couple of laps at Zolder and I think that the front tyres could have a little more heat on them, not quicker, more because I did 15 or so laps and the front tyres never passed the 70º's mark and that's a little cold in my opinion.

Other than that I think it's pretty much there, driving is so much rewarding

Agree with you Tiago, just the right front was on that temp, the left was 90° or so

In my case the top temp I got for the left one was 78º, maybe I'm not pushing enough

I have done some quick modifications and now front tyres heat up quicker, and reach and keep their optimum temp easier. Actually, I'm considering allowing the rear ones to heat up less, as they tend to raise to 115º, much more than the 99º optimal defined in the tyre file. Another thing to watch carefully is tyre pressure, if you are not doing that already. By default I would say they are underinflated. I'll take a look at that as well in the next revision

Alberto Ibañez wrote:

Another thing to watch carefully is tyre pressure, if you are not doing that already. By default I would say they are underinflated. I'll take a look at that as well in the next revision

That's a good point Alberto, since I didn't touch the default setup mainly to see how the car behaves "by default" If I can call it that way. I'll have a look at tyre pressures

You must mainly look in the garage at tyre temperature after some laps; if the tire heats up less in the centre it is underinflated (More weight resting on the tyre flanks) and if it is warmer than the exterior/interior, then it is overinflated (Getting a baloon shape that leads to the central part having more contact with the tarmac).

Wether exterior/interior is warmer than the other side is a matter of camber (Which was adjustable in the M1). If the interior heats up less than the exterior, add negative camber, and inversely. Right now I think they are a bit underinflated and OK in negative camber (It's normal that interior heats up a bit more than exterior)

P.S. when you find the best values for mixed tracks like Zolder or Donington, please say it here and I will make it the default. Then it will only need adjustments for quick ones (Hockenheim, Silverstone) or street circuits (i.e. Monaco)