[IMCWORTH]

This weekend I attended a few car meets and had the pleasure to meet some ZL1 owners (not on this forum unfortunately) who track their cars at Laguna Seca. Thunder Hill, Sonoma raceways.

Now, I am getting real close to having my car done and almost ready for the track and we got on the topic of tire pressure. I was always under the impression that a lower tire pressure at around 28 psi cold and no more then 35 hot was the sweet spot to get optimal traction. (I believe the track manual even say's the same thing)
I was told by these guys that 40Psi cold was a great start and that their track time were much better with this PSI. I wasn't completely convinced until I talked to another ZL1/1LE owner and he agreed with the higher PSI on Thunder hill and Laguna Seca.
Anyone run these higher PSI when on the track or even on the twisties for a day of spirted driving?

19" Good Year Eagles and Michelin PS4

[Og Neon]

I call straight BS on those pressures especially for the PS4s. I track regularly around the US and have been tracking on the PS4s for years. Their sweet spot is about 33-34 and I usually go our 29 front 28 rear depending on the track and ambient temps.

I think they were just messing with you because anyone going out with 40+ PSIs cold is not a track rat and not someone I would take advice from.

[IMCWORTH]

These were both very mature car Buffs I don't think they would mess with me in that manner. however I was skeptical because I know the more air makes the tire more round and doesn't sit so flat to the surface.
But then I talked to another guy who said he runs higher pressure also.
I'm very new to Track world and was wondering if different tracks work with different PSI's?

[Dabjbr]

I can’t speak to ps4s but can confirm 33/34 hot in all my tires tend to be the sweet spot… SC3, SC3R, AR1, and probably whatever I try next.

This might sound douche but I’d want to know their lap times/experience before taking their word as scripture.

I coach with HOD. Come out sometime and we’ll set you up right

[IMCWORTH]

Originally Posted by Dabjbr

I can’t speak to ps4s but can confirm 33/34 hot in all my tires tend to be the sweet spot… SC3, SC3R, AR1, and probably whatever I try next.

This might sound douche but I’d want to know their lap times/experience before taking their word as scripture.

I coach with HOD. Come out sometime and we’ll set you up right

I do a lot of spirited driving in the twisties and I feel much more comfortable with the lower PSI in my tires.

One of these guys at this car meet had some track certification of some sort with his speed listed on the certificate . I don't remember what it was. I will see him again next month.

As soon as I get my Rollbar figured out I will need or want a coach on the track.
Do you have a link for the HOD?

[Dabjbr]

https://www.hookedondriving.com/trac...rn-california/

Being new, you’ll want to sign up for A group which comes with a coach. Also, ride passenger in your coach’s car. Most bring their track cars with them. I usually take my student out at least one session, sometimes more…

Here’s Sonoma with a student…
[/QUOTE]

[AZIROC]

For my sc3's, I'm usually in the high 20s cold (27-28) but I try to keep them right around 33-34 hot.

[Og Neon]

Originally Posted by IMCWORTH

I do a lot of spirited driving in the twisties and I feel much more comfortable with the lower PSI in my tires.

One of these guys at this car meet had some track certification of some sort with his speed listed on the certificate . I don't remember what it was. I will see him again next month.

As soon as I get my Rollbar figured out I will need or want a coach on the track.
Do you have a link for the HOD?

As you get more into, you will see everyone has a different idea of what right looks like. As mentioned already, look at their lap times and compare them with other to get an idea on their credit level. I've been competing for about 20years across several platforms and several venues. You will get a lot of advice and take them as a starting point to find out what works for you and gives you the feel YOU like.

The HOD folks are a good bunch of folks and a great start to get you going.

As for the certificate, if he had a cert with speed listed on it, he is probably doing the half mile top speed events or the even longer top speed events. That is a different setup and in that case, I can see some credence to his pressure recommendation because they are concerned about rolling resistance and therefore want higher pressures. They are going in a straight line and completely different management style. A typical road course track day does not result in a certificate with a top end speed listed on it.

[arpad_m]

Originally Posted by Og Neon

As for the certificate, if he had a cert with speed listed on it, he is probably doing the half mile top speed events or the even longer top speed events. That is a different setup and in that case, I can see some credence to his pressure recommendation because they are concerned about rolling resistance and therefore want higher pressures. They are going in a straight line and completely different management style. A typical road course track day does not result in a certificate with a top end speed listed on it.

Slightly off, but I thought the reason for the high initial tire pressure recommendation for max speed runs was better heat management due to less flexing and not so much lower rolling resistance. The enormous aerodynamic drag at those speeds (180-200 mph) completely dwarfs any rolling resistance difference, doesn't it?

[airtroop01]

I run at Laguna all the time. My vehicle is slightly heavier than your ZL1, but the advice is still valid. Our cars weigh more than a true race car and tend to generate heat faster and hold it longer especially in the front. You want to maximize the contact patch without overheating the tire. If you air it down, you want to watch for sidewall flex and tire rollover.

If you run PS4S, they are a street tire and can overheat if overinflated. However, they have a relatively soft sidewall so I tend to run more pressure in those:
Front 32/Rear 30 with the goal of building 6psi with the warm up lap and
Hot being at 38/36. Bleed down if you’re at 39 psi.

I run RE71RS but I imagine it’s similar to the Goodyear Supercar 3’s, which as a 200tw tire has a much stiffer sidewall. As a competition tire, they can handle a bit more abuse before overheating. My sweet spot with them have been
Front 30/Rear 30. My hot pressure goal is somewhere around 35 hot and I’ll air down for that. Make sure you have a good quality tire gauge and check it as soon as you get into the pits.

If you find that you are losing traction out of turn 11 or feel a little loose in turn 2, lower the rear a little bit. The left front will get hammered a bit in turn 5/6, corkscrew and turn 9 so keep an eye on it and that’s why you might have heard to run higher pressure. Other than that, have a great time.