Toyo R888 Setup Notes for Spec Miata

[ScottL]

SCCA included Toyo's R888 chassis setup notes for Spec Miata in this month's FasTrack. They compared setup for the R888 to the RA1. Skip to page 11 for the details.

Don't know how much of the info applies to BMW's but I think it might be relevant for an E30 racer, which has a similar weight and chassis layout.

Highlights:

• R888 is stiffer (higher spring rate) than RA1 and generates more cornering force
• Designed to run at full tread depth; shaving can improve performance but shortens life
• Lower hot pressures than RA1 - 32-38 psi with 32 as a good starting point for lightweight cars
• Optimum tread temp is 160-220 F with a 25F gradiant outside to inside (inside hotter due to straightline camber)
• Less negative camber required than RA1
• Improved steering response = little or zero front toe

This kind of goes against the recipe offered in this thread, but I suppose there are too many variables to bother arguing about it.

[Fair]

We've talked to a Toyo national rep and he said the same thing - the R888 has a much stiffer tire carcass and capable of more performance than the old RA1... but that many road racers used to the RA1 are dragging their feet to change their setups and "don't like it" because the new tire is less sloppy than the RA1.

The R888 is a step in the right direction for Toyo. The RA1 was looooooong in the tooth and needed to be replaced long ago. Once the fast guys start to adjust their setup to the R888 I suspect they will beat the old lap records set on the RA1.

[RangerGress]

Ok, but I've yet to hear anyone say that the R888 lasts as long as the RA1. If the R888 has only 2/3rds the life, our costs are going to go up a lot.

[lazz]

Lots of misinformation about the r888. Someone should cite the wisdom about running high PSI fixing everything.

The whole thing is a debacle. We use it for a spec class (spec e30), where it doesn't matter if it's faster. The focus is on cost containment, and switching from a tire that lasts N to a tire that lasts N/2 sucks a lot.

I'm grumpy about the whole thing.

[HighandFast]

I'm grumpy about the whole thing.

Me too. Plain old grumpy about it.

[ScotcH]

We ran a brand new set of 255s for TEN HOURS at Sebring (6hr enduro, 90min enduro, 2x30min sprint, practice, qualifying). The tires are currently at 1/2 tread, and we expect to do another 2 3hr enduros with them before we toss 'em. I'd say that pretty damn good life. This is a 2700lbs DM-lite car.

[RLM]

We've talked to a Toyo national rep and he said the same thing - the R888 has a much stiffer tire carcass and capable of more performance than the old RA1... but that many road racers used to the RA1 are dragging their feet to change their setups and "don't like it" because the new tire is less sloppy than the RA1.

The R888 is a step in the right direction for Toyo. The RA1 was looooooong in the tooth and needed to be replaced long ago. Once the fast guys start to adjust their setup to the R888 I suspect they will beat the old lap records set on the RA1.

So was there any guidance on what the starting tire pressures should be? I just scrubbed in a set at the the glen on tuesday and started off high, about 39psi check hot tire pressures and they were in the 46-47 area all around. I wasn't pushing them as I only wanted to scrub them in so I don't have a grip opinion on them.

swapped to the NT-01's and started them at 34 cold and had a good time of beating on them for the time trials.

rob

[TeamSlowdotOrg]

I've run them at 42 or so hot pressure. Seemed to keep the tire consistent through the race. I'm going to take a stab at the 32 psi hot pressures at my next weekend, but I don't expect to find any miracles. Wear will not go slower with the right pressures IMO, we just might be able to keep the groove of death or graining from forming.

I wonder if the lower hot pressures are designed to get the tire up to temp faster since they say a cold tire will grain a lot worse than a tire that's warm before being asked to slip and slide under race conditions.