My car is on 245 Dunlops, and I just said it worked pretty well for me. But don't let my field testing get in the way of your theories.

 

Howdy,

How do you have the Konis adjusted John? Particularly at the rear?

Mark

 

I've got all four set full stiff. Street ride is actually quite reasonable, which surprised me. I get neither the chattering that I got with Koni Sports at full stiff on the Miata, nor the bobblehead bounce I've gotten on autocross-valved Bilsteins and Penskes set to competition settings. Just a little bit of the latter.

My performance comments are based on 1 event, after about 3-4 events on stock shocks with the larger camber difference (at which I was typically 2 seconds behind the winning times).

 

'scuse me?

Not bad for a guy with a one event field test under his belt

 

Oh, I didn't realize that you had been testing RTR setups. Sorry.

I don't plan on increasing the F/R camber differential on my car real soon though.

 

RTR is just Stock on street tires. You are not doing anything that isn't well known. Take a balanced C Stock RX8 and throw your street tires on it and see what happens ....

That said, we are not far apart in what we consider optimum. He's on the wrong tires and doesn't have enough rear camber is most of what I said and that pretty much matches what you are more or less conveying. How much rear toe you need is largely dependent on how well the engine may or may not be operating at optimum potential, which can vary greatly on this car as we all well know. The rear tire grip will impact this a lot as well, and the difference between a 285 Hoosier A6 and any 140+ street tire is substantial. The other factor is course design as the typical lot layout is much tighter and changes the game quite a bit as compared to what we had in Lincoln this year

He can't determine this for himself until straightening out the entry issue. IMO he will be better served to start with a good dose of toe in and then reduce it once he gets the basic balance where it needs to be. As it stands he couldn't carry speed in so he doesn't have a handle yet on what the exit balance will be once that is addressed.

 

I was just puzzled why you would discount what H&H ran (which I had verified worked pretty well with an RTR setup) because "they were on 285 Hoosiers", when your own advice is based on your experience with DOT-R tires. I had really just posted their setup to explain where I got mine from, not to argue against what you had said.

My experience with the S2000 and the Miata before it was that a setup that worked for DOT-R tires didn't require much tweaking for high performance street tires. It's looking like that's also true with the RX-8.

 

I'll give you one further; in my direct experience of having run on most of them on the same car myself there are some surprising differences in setup vs balance vs surface type even among the various street tires we're discussing. Based on seven years of "theories" what else would you expect me to say other than what seems obvious to me after all this time?

 

Would you recommend the Toyo R1R over the Yokohama AD08? (Dunlop Star Specs and Hankook R-S3 are not available where I live.)
I'm asking because these French guys were surprisingly faster on a track with the AD08 than even the R888: http://trackparts.ch/images/pdf/semi...chappement.pdf

Also, a rim width size of 9.5" is allowed where I live. Would you run 255/35 18 or anything wider (street tires)?

 

They are running at the track, entirely different situation

I should have a Mazdaspeed front sway bar for sale soon if anyone is interested, quite a few people like using them for CS and RTR

 

Does that mean you'd definitely prefer the R1R over the AD08 in an autox race?
Some mentioned that the R1R has a relatively soft side wall. If this was true, is this even relevant or even a disadvantage concerning the RX-8?

(Where I live rims can be changed in stock class but somehow nothing else. But does your sway bar have the some color as the stock sway bar?).

 

yes, but the R1R only has the grippy soft compound down until the tread is about 3mm deep, then the performance is gone. On a track it will overheat quickly.

the AD08 will feel better, but not have the same grip level especially in cooler weather. It needs heat to start working well so it is better for multiple lap track type events

The Toyo works better with the sidewall slightly stretched so 255/35 on a 9.5" wheel is a good choice.

 

Thanks. That would mean that the R1R doesn't last very long as the tread is only about 6.5 mm deep.

Is the optimum found at a width of 255 (weight of tires, tires heating up etc.) or what's the reason people don't seem to run 265 tires even though the rules would allow it? (Sorry, I haven't followed this forum for a long time).

 

miscalculated in my head; 3mm

 

Bringing this back up as I'm looking for some guidance on alignment settings.

The Miata is down for a DP build for 2013 so I'm gonna run the 8 in RTR this year.

Have OTS Konis and will be buying the new Dunlop ZII's (245's I "think" I'm going with) and will be mostly on airport sites with a few smaller parking lot venues in NCR SCCA's area.

Anybody willing to share a good alignment?

FWIW, I will still be changing tires at events, the Dunlops will be Autox only.

 

Plenty of other threads on this, but basically:

1) Max out the front camber.
2) Done

(5 years and two classes later I litterally haven't changed the alignment since this)

 

Gracious

 

Yeah what he said!

 

Pax racing is for p#ssies

 

Oh I don't disagree

But in order to keep autoxing this season, gonna keep it sweet and simple as all the $$$ is going to the hairdressers car!

Here is Frank right now

 

not bad for a chicks car

 

Howdy,

So... Have run a few events now this year.

Changes: Tires are now BFG Rivals (245/40-18). Alignment change in the rear to -1.5 deg / zero toe. Shocks are now revalved DA conversions that I got used from Carter T.

Last year, I had pretty serious issues at Nationals with the car trying hard to spin on corner entry (with -1.1 deg rear, zero toe, and on Michelin PSS). Locally on a lower grip asphalt lot, the car was perhaps a little loose, but still driveable.

This year, the car has been pushy on the lower grip asphalt lot with the same setup being pretty close at Peru this past weekend. Car was a bit pushy steady state / from mid corner off, but was still loose enough that the back would move under trail braking (on the edge of moving too much).

I'm trying to figure out / guess if that's likely due to the camber change, tire change, or shock change. Remember, only make one change at a time! :-) The front bar right now has remained set full soft, and I'd like to make the car a little bit looser and put the front bar in the middle of its range, so that I can adjust the car a little more to suit courses if needed.

So my question is... How sensitive are these cars to rear camber? Would another half degree of rear camber typically take one of these from being very loose to being neutral?

Related questions... So far with both setups when I've taken the car from a lower grip surface to a higher grip one, the car has loosened up. Typical? The stuff I was otherwise used to drive would usually tend to tighten up as grip increased.

On adjusting the rear camber, on these cars will adjusting the rear camber also change toe? I'd expect that it would, but figured I'd ask anyway. If it doesn't, and I get seriously motivated, I might try some quick changes to see what they do.

Mark

(and, once again I want a car to be tighter on corner entry and looser off the corner. I wish there was a **** to let me do that, vs. needing to compromise! :-)

 

I can't speak to the RX-8 specific stuff, but the above should be doable (or at least helpable) using shocks now you have DAs. Tune alignment until the car's neutral to slightly pushy, then turn up rear compression and/or front rebound until the back end moves the desired amount at corner exit.

 

^^This. The converted DAs really helped. Now if I can only find someone to buy my set.

 

You have so many things backwards wrt understanding its hard to begin


First, no RX8 on street tires should have zero rear toe for competition use. While the factory alignment setting is almost zero it also is minimal front camber. You have taken stock class R tire info and not recognized the grip difference changes required by real street tires.

Shocks are for transitions such as slaloms, offsets, etc. and mostly corner entry and some corner exit.

Springs and swaybars control mid-corner/steady state handling balance.

Try this:

Max front camber (should be somewhere around -1.8 to -2.0 deg with those shocks)
Minimum caster (around 4 deg, maybe in the 3 range)
1/8" - 1/4" front toe out total

Rear camber should be between equal to 0.3 deg less than the front
1/8" toe in per side (1/4" total)

Your first goal is to get the steady state handling neutral combined with tire pressure settings. Then tune for transitions. It can be an interative process.

.