Search machine sucks.....

What are you guys' experience on the best pressure for the Toyo RA1? Preferrably hot pressure.

Thanks in advance for any info.

 

About 40 hot in front, and however much appropriate in the rear to get it to rotate.

Warren

 

 

I like them around 34 lbs hot. At 40 I find them too greasy.

But it depends on how long you plan to run them - for a shorter session maybe 40 is better.


[Modified by Big Phat R, 7:57 PM 10/15/2002]

 

Thanks for the input guys.

I found that for the Kumho Victoracer, the optimal pressure needs to be around 47psi because of the soft sidewall. It's a lot more than the A032R that I used to run. Looks like the RA1's sidewall stiffness is comparable to the A032R so the hot pressure doesn't need to be as high as the Kumhos. Glad that I asked.

 

I still haven't figured out where ya'll get those high pressures from. I run 35psi hot regardless of activity in my 2500lb RX-7 (not much lighter than modern Teg or Civic and heavier than old-skool Civics).

 

I never ran that high of pressures w/ my Kumhos. 38-40 hot was max traction. Anything above or below that will just be to change handling characteristics.

Warren

 

I allways thought that the Kumhos had stiffer sidewall than the Toyos... The Toyos are like jello when you manually push sideways on the tire compared to Kumhos which don't even budge at the same pressure. Not a very scientific experiment, but still...

On my 2200lb car, the 205-55-14 Kumhos on a 6.5" rim will not even roll on the sidewalls at 30psi hot and with a stock suspension... And they work best at 39-40 psi hot...

 

I started from 36 hot (that's what I ran with A032) and the Kumhos were rolling on the sidewalls pretty bad.... I could see a lot of scrub marks on the sidewall until I up the pressure to about 47 hot.

I met Toby G (won 3rd national in SSB class) and rode with him in my car. He even advised me to go as high as 48 to 50psi ! Although he races on Hoosiers, he said 45 to 50 is the hot pressure that they found best for the Kumhos.....

But anyway, I would believe that the pressure for RA1 doesn't need to be so high. I will try out you guys' recommendation this Sunday for my last event of the year.

 

AIM tire, Ron Cortez where I bought my RA-1's from said Marc Kirberg, previous sears point ITA CRX record holder, ran around 40 psi all the way around. Bernardo Martinez, current record holder at Sears Point on a CRX runs 35 psi all the way around. I switched to 35 and liked 35, but I actually seemed to be slower, however, that could be that the tires are just older. these are all on 14x7 panasports, but i think bernardo might have shoved 225 in the front, whereas I run 205, not sure what kirberg ran. so stay within 35-40 and you wont do wrong.

Both cars were running on illuminas btw.


[Modified by Tyson, 9:23 AM 10/16/2002]

 

45+ for Hoosiers is fine, and works well on heavier FF cars.

If you have to run more than 40 hot in the front, then the car is understeering, or you're overdriving the front tires, or a combination of both.

Warren

 

Wai - do you have a pyrometer??

 

No I don't....
For the track days that I go to, they're usually 20 mins sessions with one hour in between. Would tire overheating be a problem?

 

Well you basically just want even (or even as possible) temperature spread on the tire.

If the tires feel greasy or loose (i.e lots of steering input - poor vehicle response) - then I would say that they may be overheating. Try taking tire pressures immediately following your session. Depending on the track configuration - usually one of the front tires will be smoking hot (depends if the track is clockwise or counterclockwise)