I just purchased a set of the Toyo RA-1s and I have a couple of questions I'm hoping somebody can help with. These will be used for track days and SCCA Time Trials.

1) What kind of camber do these tires like? I'm currently running -2.2* up front and -1* in back.
2) What have people found to be a good pressure for these tires?

thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">I just purchased a set of the Toyo RA-1s and I have a couple of questions I'm hoping somebody can help with. These will be used for track days and SCCA Time Trials.

1) What kind of camber do these tires like? I'm currently running -2.2* up front and -1* in back.
2) What have people found to be a good pressure for these tires?

thanks </TD></TR></TABLE>

I'm pretty sure toyo reccommends 3 to 5 degrees negative. I have been using 2.5 and had good results. The pressure, I usually shoot for 40 psi on a hot tire. Usually start out about 32 in the front and 35 in the rear (on a hot day).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bosco500 &raquo;</TD></TR><TR><TD CLASS="quote">I'm pretty sure toyo reccommends 3 to 5 degrees negative. I have been using 2.5 and had good results. The pressure, I usually shoot for 40 psi on a hot tire. Usually start out about 32 in the front and 35 in the rear (on a hot day).</TD></TR></TABLE>

Agreed on both points. If you have a pyrometer, you'll want the tires to be in the 180 - 190* range hot. That should equte to roughly 40 psi. If you're getting hotter on the outside than on the inside, then you could use more negative camber. However, what you're running right now is a very common setup.

 

you will find ALOT of different answers.

i know some people who start around 32-33f/r and then i know people who start down in the 25-28psi range.


I have been runing mine at 28f and 29r. I haven't goten a chance to use a pyro yet, but when i started out high, the tires would fall of at the end of the session

 

ITS GSR, ran on RA1s for the past 2 years. 205/50 and 225/45/15

~ -2.5 front camber -2.0 rear camber
I start them ~29PSI cold up from and ~32PSI cold out back.

 

cold pressures at 31-32f, 35r seems to work well for me. I take them again when I come off the track, I like to see pressures in the 38-40psi range hot.

 

FWIW, Toyo recommends that the optimum range to be 39-41psi hot. I think it really depends a lot on the track temp and the width of your tire though... but even with my 275s, it seems to hold true. I usually start around 30 at the beginning of the session.

 

Thanks for all the replies guys - gotta love this forum.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">
1) What kind of camber do these tires like? I'm currently running -2.2* up front and -1* in back.
2) What have people found to be a good pressure for these tires?
</TD></TR></TABLE>

You're talking about your ITR, right? You can go a little more negative in the front but I wouldn't worry too much. You'll do fine the way it is. My own ITR is -2.5 F/-1.5 R.

At Summit Point, I am cold 30 psi except the left front, which I put at 28. When I come off the track all four are at 41/42 psi.

 

Use a pyrometer and monitor the tire for even wear. That way you will know the whole contact patch of the tire is working for you. Driving style, car setup, track and ambient temperature all have an effect on what is right for you. World Challenge guys run their tires at well over 200 degrees, on shaved RA-1's, but they drive their cars very hard and they have extremely stiff setups. I think they said on a recent broadcast of the PIR race that they run 210-220 degrees, but sometimes approach 300 degrees. Then again their tires only have to last one session.

Here is a listing of the various manufacturer recommendations and data:
https://honda-tech.com/zerothread?id=1250903

 

You should also keep notes of your tire temps, pressures, alignment settings, lap times etc. if you want to get faster. Here is a nice article about keeping records:

http://www.turnfast.com/tech_p...shtml

Pro race teams are manic about keeping notes because they like to get faster. Just get a clip-board and some data sheets. Print your own or spend $10 and buy these:

http://www.longacreracing.com/...id=10


Very cheap compared to the price of a set of tires. As for a pyrometer, get this, at about the price of one tire:

http://www.longacreracing.com/...tid=7

 

What are the pros and/or cons of using the pyrometer Descartes posted versus an IR pyrometer ?

 

IR doesnt give the most consistent results, and for tires it will only measure the surface temp - you need a probe to see what the tire temps really are.

 

If you're getting that pyrometer... Get the package that includes the coiled cord and carrying case. The tips are delicate and expensive, so you want to avoid breaking them. The coiled cord gets out of the way much better too.

 

thanks for the infos.

I'll stick with the IR one for now since I can borrow one for free at work.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote">You should also keep notes of your tire temps, pressures, alignment settings, lap times etc. if you want to get faster. Here is a nice article about keeping records:

http://www.turnfast.com/tech_p...shtml</TD></TR></TABLE>

Thanks. I am already very strict about my record keeping at each event. However, I do not currently keep any record of tire temps. I am planning on purchasing a good probe pyrometer to begin recording this data.

Does anybody know of any good articles describing the proper method for measuring tire temps and how to interpret the data?

 

Here is the official word (well from Australia at least!) from Toyo on Toyo RA-1's:
http://www.toyo.com.au/Pit%20Lane.htm
http://www.toyo.com.au/tech_info15.html
http://www.toyo.com.au/TechInf...s.pdf


Here are some links to articles on tire temps:

Pyrometer tips
http://www.longacreracing.com/...ID=16

Prove vs. Infrared
http://www.longacreracing.com/...TID=9

http://www.redlinerennsport.ho....html

http://popularhotrodding.com/tech/0311phr_tire/

Toyo Proxes RA1 Usage Guide
http://features.evolutionm.net...es/46


Modified by descartesfool at 12:50 PM 8/29/2005

 

Thanks man, that rocks!

 

Well, I run camber 3.0m front, 2.0 rear.

I adjust tire pressures so that when hot they are exactly 40 PSI. So at Mosport I run

LF : 31
RF: 33
LR: 34
RR: 35

And yes, every track is different.

Best method:

Overinflate tires a little at beginning of session (35 or so all round), run track session. At end of session, bleed tires to 40 psi hot. After tires cool, measure pressure. VOILA! That is your cold tire pressure.