[thunderBMW]

Anyone know what the best hot tire pressures are for track use? (Maybe from the BMW driving experience ?).
Thanks

[Hossel19]

Typically you want to be around 38-40 hot (start around 30-32 cold)depending on the tires. Some require more heat others less, this information is usually available from the tire manufacturer.

[oj34]

Here are some pretty good values from the german Sportauto test (translated by me, so pls. be patient):

"Instead of the recommended warm tire pressure of 2,2 bar for all wheels for Hockenheim the recommended tire pressure for the Nordschleife is 2,5 bar warm for front tires and 2,0 bar warm for rear tires"

For the non Europeans :
- Hockenheim : GP track with perfect surface
- Nordschleife : well, you should now that
- 2,0 bar ~ 29 psi
- 2,2 bar ~ 32 psi
- 2,5 bar ~ 36 psi

(german original) "Statt des für Hockenheim empfohlenen Warmluftdrucks von 2,2 bar rundum wird für die Nordschleife ein Luftdruck von 2,5 bar warm an der Vorderachse und 2,0 bar warm an der Hinterachse empfohlen."

This information is from BMW test drivers for the factory installed Michelin Pilot Super Sport, I think you want get any better source of information.

[MilehighM3]

I seemed to settle on 32-33 front and 35-36 rear when hot.

[thunderBMW]

Originally Posted by oj34

Here are some pretty good values from the german Sportauto test (translated by me, so pls. be patient):

"Instead of the recommended warm tire pressure of 2,2 bar for all wheels for Hockenheim the recommended tire pressure for the Nordschleife is 2,5 bar warm for front tires and 2,0 bar warm for rear tires"

For the non Europeans :
- Hockenheim : GP track with perfect surface
- Nordschleife : well, you should now that
- 2,0 bar ~ 29 psi
- 2,2 bar ~ 32 psi
- 2,5 bar ~ 36 psi

(german original) "Statt des für Hockenheim empfohlenen Warmluftdrucks von 2,2 bar rundum wird für die Nordschleife ein Luftdruck von 2,5 bar warm an der Vorderachse und 2,0 bar warm an der Hinterachse empfohlen."

This information is from BMW test drivers for the factory installed Michelin Pilot Super Sport, I think you want get any better source of information.

Thank you.
So just to be clear, I should set the front to 36 psi and rear to 29 warm - correct?

[M3 Adjuster]

Originally Posted by thunderBMW

Thank you.
So just to be clear, I should set the front to 36 psi and rear to 29 warm - correct?

If you are running the Nordschleife

Otherwise it recommends 32 all around for other tracks

[oj34]

Originally Posted by M3 Adjuster

If you are running the Nordschleife

Otherwise it recommends 32 all around for other tracks

Exactly. Not sure if you have something similar to the Nordschleife in canada?

[gmzanatta]

Originally Posted by oj34

Exactly. Not sure if you have something similar to the Nordschleife in canada?

Hahahaha I wish!

Also curious where the OP will track, not many good options in the great white north.

[M3 Adjuster]

Originally Posted by gmzanatta

Hahahaha I wish!

Also curious where the OP will track, not many good options in the great white north.

Calabogie, Mosport, and Trois Rivere are all on my list of tracks I would like to drive in Canada

[Hossel19]

Originally Posted by M3 Adjuster

Calabogie, Mosport, and Trois Rivere are all on my list of tracks I would like to drive in Canada

You should also add LCMT (Mont tremblant) 1.25 hours north of Montreal, one of the nicest tracks on the east coast. They ran few F1 races there in the early 70's I believe.

[Franzino]

Originally Posted by M3 Adjuster

If you are running the Nordschleife

Otherwise it recommends 32 all around for other tracks

I find it strange that the pressure on the Nurburgring is a lot lower at the rear then at the front. With my Z4M with 19" csl wheels and same supersport tyres I drive with 2.25bar front an 2.35bar rear on the ring... When tyres are hot!

[Robin_NL]

God how I hate imperial(vs metric)....


Cheers
Robin

[Robin_NL]

Originally Posted by Franzino

I find it strange that the pressure on the Nurburgring is a lot lower at the rear then at the front. With my Z4M with 19" csl wheels and same supersport tyres I drive with 2.25bar front an 2.35bar rear on the ring... When tyres are hot!

Lower tyrepressure means more grip/traction...

So more stable rear end at Ring...

Cheers
Robin

[M3 Adjuster]

Originally Posted by Franzino

I find it strange that the pressure on the Nurburgring is a lot lower at the rear then at the front. With my Z4M with 19" csl wheels and same supersport tyres I drive with 2.25bar front an 2.35bar rear on the ring... When tyres are hot!

I do as well actually , I've always used a slightly lower pressure up front than on the rear on every BMW I have ever driven.

Apparently they must anticipate a ton of heat being generated at the rear tires on the Nurbugring and agree with Robin_NL it would provide more grip at the rear. Everything BMW does with this car is respectful of the rear end in an effort to keep it planted, unlike the 1M and M4. Of course they still don't trust journalists or non racers to drive a manual M2 with DCT off on the track....

[Robin_NL]

Originally Posted by M3 Adjuster

I do as well actually , I've always used a slightly lower pressure up front than on the rear on every BMW I have ever driven.

Apparently they must anticipate a ton of heat being generated

In the case of the Nordschleife they didn't want the rear end to slide like on Hockenheim Short where that setup proved to be Nr1 in laptimes (1:12.2)

So how can you make the rear end a bit more neutral in that case(NS): less pressure in the rear tyres(= more traction/grip) and more in the fronts(a tad more understeer so to speak) to get a faster laptime. And they're talking about one fast lap(or 2) on the NS. It's not like being on a trackday the whole day...

Cheers
Robin

[M3 Adjuster]

Originally Posted by Robin_NL

In the case of the Nordschleife they didn't want the rear end to slide like on Hockenheim Short where that setup proved to be Nr1 in laptimes (1:12.2)

So how can you make the rear end a bit more neutral in that case(NS): less pressure in the rear tyres(= more traction/grip) and more in the fronts(a tad more understeer so to speak) to get a faster laptime.

Cheers
Robin

Agree totally. We were typing at the same time!

However, a .5 bar/7 psi delta from front to rear is such a MASSIVE difference front to rear ... That's an absolutely *radical* change from even pressures all around...

And yes, I would bet those are both settings for one optimal lap in either situation , whether at hockenheim or Nordschleife. Of course to be honest , with the Michelin pilot super sports on a warm day.. That's about all one can achieve ... One hot lap.. Before they just about melt on you ... .

Looking forward to a little more time in an M2 and my 1M. On track at COTA in a few weeks ...

[Pyrat 2]

I ran about 35 to 36 hot a couple weeks back and it seemed to work fine. A lower pressure might have been better but there was no greasiness at all at the pressures I ran. Warning though. After cool down I dropped to below 30. For my next session I went out and the tpms sensor turned on the stability and traction control. Also pulled back the throttle significantly. I had to attempt to heat up the tires under these conditions. I then pitted reset the tpms and turned off and restarted the car to get everything cleared. Not very much fun. They need to either disable this nonsense or disable the TPMS whenever you disable DSC and DTC. Of course this is probably against the law for them to do this - disable TPMS. So they should just not have it intervene and simply warn you that your tire pressures are low.

[F87LUV]

Originally Posted by M3 Adjuster

Agree totally. We were typing at the same time!

However, a .5 bar/7 psi delta from front to rear is such a MASSIVE difference front to rear ... That's an absolutely *radical* change from even pressures all around...

And yes, I would bet those are both settings for one optimal lap in either situation , whether at hockenheim or Nordschleife. Of course to be honest , with the Michelin pilot super sports on a warm day.. That's about all one can achieve ... One hot lap.. Before they just about melt on you ... .

Looking forward to a little more time in an M2 and my 1M. On track at COTA in a few weeks ...

So what happens if I don't drop the pressure for a track day?

[gthal]

You need to chalk your tire's sidewall and adjust higher/lower to manage the contact patch if you want a good hot pressure IMO. Every car/tire combination is different. I'd use some of the recommendations here to start and go from there.

[IS+1]

Originally Posted by F87LUV

So what happens if I don't drop the pressure for a track day?

In my experience, dropping the pressures for track use is the single most important thing you can do to your car, to ensure safety and car control on the track. Running cold stock pressures will lead to excessively high pressures once hot (I've seen over 50 psi), which will lead to no front end grip (understeer), no rear end grip, overall twitchiness and a very unstable rear end especially under heavy braking/trailbraking. I drop my pressures to about 30 psi cold, which equates to about 38-39 psi hot. In order to get equal hot pressures front and back (if that is your goal), drop the front pressures a bit more because they will heat up more than the rears. Once you set your pressures initially and go out for a lapping session, re-check your pressures immediately afterwards, because 9/10 times they will need re-adjustment.

For reference, I track my car at Calabogie.