I need some help with what tire pressure to use for a BMWCCA school at Laguna Seca on Monday. I am running Bridgestone S-03's, 205-50 16 on the stock 16" wheel. Temperature will be in the mid to low 50's, partly cloudy. Session time will probably last 25 minutes. Thanks in advance for the advice.

 

Some of it depends on mods, and the temp and sunny vs. overcast also have an effect... With my mods and given that I usually run in the red group, I normally run 36/34 on cooler days. I'm not saying that will work for your car, but for mine that's a great setup. A little less pressure lets my tires warm up quicker and stick better from the get-go - and they don't get gain too much pressure, either.

If you have a rear swaybar and it's set to full stiff, I'd recommend running 2 psi less in the rear - otherwise, you may find yourself a bit tail happy for the track.

On warmer days, above 70, I run 38/36 because the tires will already warm quicker and it helps avoid getting too much heat in the tires (which will make them go away a bit and get greasy).

Many beginners find the car more controllable with equal pressures front and rear - my car, however, gets a bit squirrely like that. Just take note about how the car feels while you're out there!

I'm running Falken Azenis for DE's and autocross, so YMMV - I think the S-03's will be pretty close, though. Check your pressures after you get off the track and adjust accordingly - if you have a pyrometer or access to one, check the outside, middle, and inside. They should be pretty close. Also, adjust pressure based on what you're feeling - if you feel the tire rolling over, you'll need more pressure. You can always use the chalk test to dial them in, too.

 

Thanks scobib,
I have the Madness swaybar at the middle setting. H Sport springs, 15% pulley, CAI, and UUC exhaust.

 

Laguna Seca, awesome! The instructors will help you out. Have fun and remember, shiny side up!

 

I did a day at Infineon in November. It was low 50's and I went 38/38 whith khumo's. Back end was happy,so I dropped to 38/36 with better results.

 

Hi, I'm also attending the Laguna event and wonder if tire pressure for lower profile tires are different?

I'm currently running 215/40/17 with pressure 36 up front and 35 in back.
Do I need to run higher to keep the front tire from rolling over too much, or will the lower profile prevent that on it's own?
I have no other mods.
Cheers,
Skottoman

 

It all depends on the tires you're running... If it has a flexy sidewall then yes, run a bit more pressure. Maybe 38/38 and see how that works since you don't have a swaybar...

 

I'd say 36/34 would work well for you... But, you'll have to go out there are see how it works, then adjust... Have fun!

 

Thanks. My tires are Yoko ES100's.

So you think with the stock setup that equal F/R pressures would work well?
Cheers,
Skottoman

 

Hrm... do those have the reinforced sidewall? I think they do... I'd still say 38/38. With the stock suspension, a little more pressure in the rear will help the car rotate. If you get any oversteer, back the pressure off in the rear by about 2 psi at a time until you've dialed it out.

But, I think 38/38 should work well - it should be enough to keep the tires from rolling over, which can cause the ES100's outer shoulder to chunk when they get hot...