This email was sent to me, comments from AIM Tires: No affiliation just passing it on



....RA-1 Vs R-888 + NEW ALIGNMENT SHOP
Description: There are a multitude of questions being asked about the difference between the RA-1 and the new R-888.

Our company was the very first company to sell the RA-1 in the U.S.A.back in 1992. In fact we were the company that originally tested a prototype RA-1 that allowed TOYO the feedback necessary to commit the RA-1 to the USA market. Thus, we have a bit of experience with the RA-1 tire!

The greatest difference between the RA-1 and the R-888 is the tires construction. The R-888 is of an all new design both in tread and construction.

The most obvious difference being the tread pattern and molded tread depth. The R-888 grooves are molded to 6/32nds of an inch. Whereas the RA-1 grooves are staggard with the inner grooves at 8/32nds of an inch and the outer most grooves at 6/32nds. Additionally the R-888 has less and larger tread blocks to promote a quicker steering response and better mid-corner grip.

It should be noted that shaving a R-888 due to the wider grooves will not ceate a 'slick tire' as in the case of shaving a RA-1 to below 4/32nds. The R-888 when shaved to a low 2/32nds will not become a virtual slick tire but will continue to have wide rain grooves.

The wider grooves on the R-888 does enhance the wet weather performance of the tire and has proven superior in the wet than the RA-1.

To maximize the performance of the R-888 over the RA-1, on ALL race cares and especially Front wheel drive RACE cars and Spec Miata's: The camber, toe, caster tire pressure and even the driving technique must be modified.

The R-888 with the stiffer sidewall and softer undertread construction requires a bit less initial camber settings and higher pressure. Or you can run very well with your original camber settings and by simply increasing your STARTING pressure.
This will be hard for you to believe, but the higher HOT pressure WILL provide you with BETTER tire wear.
Yes, yes I know this doesn't make any sense whatsoever. But, just TRY IT! And you'll see what I mean.

By design the R-888 promotes higher levels of grip under braking and at mid-corner.

So, if you simply switch a RA-1 for a R-888 without changing your chassis set-up please don't expect your car to rotate in at mid-corner without taking camber out of the rear suspension settings.

Furthermore, a bit less camber in the front will aid turn-in and an increase in starting and operating pressure of the R-888 over the RA-1 will aid in overall traction.

At the higher pressure the R-888 is a VERY comfortable tire to drive quickly. Low pressures will cause an unstable feeling. Keep this in mind.

WE CAN HELP.
A.I.M. has an all new RACE CAR chassis alignment/corner weight facility to 'dial in' your race car like never before!
Located here at Infineon Raceway, across from the AIM shop we have teamed with the very capable TIM BARBER, renown Championship winning race driver and chassis guru. Tim can also provide personal coaching to enhance your driving experience and winning percentage!

CALL AHEAD for an appointment, you will not be disappointed with the performance gained from someone who knows how race cars SHOULD handle.

Questions? Call us we'll be glad to assist as much as we can.

Thank you, Ron Cortez

 

Interesting as I have been trying to dial in my car well for these tires... When they say dial in less camber, for a race car this would be going from -4 or higher down to ?? I am running -2.5 on my GT2 all around as they recommend -2.5 up to -5 for these tires..

They are most def. sensitive to pressures as well.. Too high of a hot pressure and they get scary, too low and the car feels wallowy/disconnected and unstable.. Overall though once you experiment they are great tires with an abundance of grip.

 

How about some actual numbers? What kind of pressure increase would be typical, on a car moving from the RA1 to R888s with no other suspension changes?

 

I'm using up my RA-1s and just moving to the 888s, and I just had an interesting conversation about this with our tech director that recommended some really crazy high cold pressures in the neighborhood of 40 COLD, with a working hot pressure of 48! This seems to reinforce some work that our 944Spec group (M758 in particular) has been doing for some time now...interesting... typical RA1's are 10lbs less...

 

WHOA, I have been starting out at 28 cold to get to about 38 hot all around!!!!! This seemed to work real well, over 40 and the car felt scary?!

 

I found them to get slippery at RA1 pressures last year but I was likely overworking them too as I am still working on perfection. They seemed better a couple PSI lower to me. I have heard pressures all over the map from various folks on these, though I never personally tried them at such high pressures.

Yet another test for early this year I guess.

 

Yeah, sounds strange. Ill have to follow this thread to see what you all think of the tires and the pressure changes to make them work as good or better. some of the WC teams should have some good information here. I learned a lot from the caddy folks when i was hanging around their tent during the GT races I ran with the RA1s.

mk

 

For my car, GT3RS, Front hot at 33-35 and Rear hot at 36-38 feels optimal for R888s. Any higher and it's like the car's on skates. Depending on ambient temps, I ususually start with 29 lbs cold all around.

 

One thing I can say for sure is that, for the occasional weekend DE participant using a street car, the RA1s require a lot less thinking and wrenching. Bolt them on, check pressures and go. Bodes well for the Nitto NT01/NT05.

 

I have used RA1's and R888 on my street car....at the time it was a 07 Carrera S. The RA1's seemed to work best at around and no more than 38psi. The R888's seemed the same to me and I had them over 40psi in the rear when they heated up and they were a mess then so i lowered the pressure and they got better.

 

I am seeing some info for front-wheel drive cars and an ad for an alignment shop. Where are the camber, toe and tire pressures for RWD cars?

C.

 

Yea I thought it was interesting, those pressures are really high in my book, It does sound like the light weight and tire for the spec series drives some unique issues, but it from what I'm being told it translates over into the bimmers running on 888's as well....we'll see what transpires...

 

After driving TWS in the rain this past weekend with a brand new set of sticker R888's (unshaved), I think they are great rain tires. Very good in standing water. But like everyone else, I still don't know what is the "right" pressure for them.

 

Jim that is old news now. I am running arund 40 psi hot in the R888 as are all the fast guys. I did try as hgh as 48 psi hot and it was not horrible, but as I lowered the pressures a couple psi the tires got better. I have settled around 40 right now.

 

Joe, glad you popped in, I dropped the car over at GA to get a dyno tune on it, and Jim mentioned the higher pressures...I know you'd run higher, but 48 was a bit of an eyepopper!...