Tire preausre

[2k2miata]

Hi guys

I was just wondering what kind of tire presures you guys run at events

I usually run just over 40PSI (Street tires)

What kinda PSI do you guys recomend.

[Shaman]

34 rear, 36 front. Cold.

[Marsh]

Originally posted by 2k2miata
Hi guys

I was just wondering what kind of tire presures you guys run at events

I usually run just over 40PSI (Street tires)

What kinda PSI do you guys recomend.

This isn't going to do you much good, as every car is VERY different and every tire is different for one given car. In my 3000lb car on 225 tires I run 42 or so up front in my R-compounds, and 32-36 in back for what ever tires I'm running.

[ice/solo racer]

I was seaching for the proper pressures in my first gen khumos and my pyrometer had me in the low to mid fortys but I found the grip sucked.So I talked to Stephen Tong(we both run RWD cars)and he suggested going way down to around 32 front and as low as 26-28 rear.I said that at the higher pressures the temps were good and the shoulder rollover looked spot on,he said not to worry about rollover and give it a try.
So I did(my corolla only weighs about 2150lbs)and the grip did improve,BUT the first third of the tire in from outside has MUCH more wear in just a handfull of runs.Luckily the khumos can be remounted inside out to preserve them.
Like Marsh says,every car will require a little different pressures to optimize that cars setup,but the trends should remain constant.If you run a FWD car then get the front as good as can be and then fine tune the rear to allow correct amount of rear slip,keep in mind that the sidewalls of r-coumpounds are stiff enough to allow low pressures and bigger slip angles,increasing the pressures to much wont necessaryly deform the contact patch enough to reduce grip.If you have RWD than good luck,trying to get the car to rotate on corner entry and still have enough grip for a decent exit is more suspension tuning than tire pressure.This is the problem I face with my car,I'd offer solutions if I had it all figured out,but I don't.
MY advice is to purchase a tire pyrometer and ask as many people as possible at the events,most of us are only to willing to help if possible.

[roooo]

You have it easy in a Miata because there are lots of other people to ask.
On street tires, you may not have much pressure range to play with to get both grip and sidewall stability.

Conventional advice says to run higher in front than in back. Advice posted on the Subaru Club board says start at Max PSI + 5 lbs and then adjust from there...

For my car (3rd gen Protege), the latest I've heard from a fairly successful guy in the USA is that he runs his Hoosiers 7 lbs more than the fronts ... something way up there like 49 and 56 psi. Not to mention that his front and back tires are totally different sizes. I think for the next couple of events I'll do some experimenting.

[Shaman]

Hmm. I never figured out why everyone runs so much pressure. My best traction seems to be around 40-42PSI hot.

[AcidGord]

While I was still running on my streets this season I got up as far as 45psi front and I was still rolling more than I would have liked while my rears were down to 32psi and weren't rolling a bit. (93 Civic hatchback, Eagle HPs on 14" OEM wheels)

Now I switched to Rs and have to learn how LITTLE pressure I need to put in. (I've been told as low as 22psi)

[JGraves]

I run around 36psi cold (front and rear) for solo 2 in my 2000 Miata. I use 225/45R15 V700 Escta's on 7" rims.

Jeff

[ice/solo racer]

I ran street tires at all but one event,so I'm pretty familiar with them and their pressures.I also don't drive a miata or have it easy,I drive a OLD corolla GTS thats rear drive and has a solid rear axel like a truck,not independent all around like a miata,nor is the corolla blessed with a 50-50 weight bias like the miatas.
I have most of my limited autox driving FWD and I can say that FWD is alot more forgiving and alot less demanding to coax consistantly quick runs out of,not to mention a bunch easier to set up for solo's.That said,I love the challenge of setting up/driving my corolla to my/its limits.
I'm proud to say that when Stephen Tong ran the falkens on his miata(he's a great benchmark to aspire to)I was within a tenth or two at 2 events and outran him at another.I was also the fastest RWD at the top gun shootout in the rain(I ran my falkens,not 32Rs,no lsd,no traction control!)
Don't want to sound like I'm venting or preaching,I just take offence to saying that I have it easy.

[blur]

For Solo2 cold pressures can vary depending upon what you want. If you start higher you will have more grip at the start of the run and it will be more consistent over the run. If you start lower the tire flexes more and puts more heat into it which gives you more grip towards the end of your run. The hard part is obviously finding the happy medium.
BTW, most radials will work best at 40psi hot, it's how they work getting there that matters in our cases.

Oh yeah, I run about 34f 36r cold on Toyo's,

[roooo]

ice/solo: I meant the original poster had it easy ... since his alias is 2k2miata ... not that you have it easy in a Corolla!

Ahh the troubles of non-threaded forums :)

[ice/solo racer]

Sorry Rooo,I thought after I posted that you may have meant the tread starter but it was too late to change,besides I thought it might be interesting reading the aftermath!.I must have had a bad day at work and got a little pissy.
It may also be that I took two years to build the corolla,mostly to try and get to the shootout and then it bloody rains,dozens of events in the car in the dry and then it bloody rains.
Also I don't think anyone really has it easy in this sport,too many variables from one event to another.I hope the classing doesn't change to much this winter so we don't have the same type of thing that happens in the SCCA,meaning you need the right car per class to be competive.
I like the wide range of cars to compete against in BSS alone.