Got 4-5 hours of clear weather Saturday, and finally able to bring the car to track. Due to the last minute notice, I only manage to do an alignment:
FRONT:
Camber: -1.1
Caster: 6.0
Slight toe out

REAR
Camber -1.5
Slight toe in

(Will update exact toe specs later on)

Stock Bridgestone Potenza RE050
Start of day: 34F 36R
Mid day adjusted to: 32F 35R
Weather:
Overcast, 84-90F, 70-80% humidity

Track condition:
Dry, ponds in runoff(!)

The first thing we received over there, was a warning by a friend who worked at the track -- don't go off or you'll see some splash. Scary.

Anyways, after everything is done, here's the impression:
Good chasis balance.
Good brakes.
Good in sweepers.
Easy to drive.

Bad stock tires.
Bad shocks.
Bad in transition stuff
Too understeery at this point.

Overall, this felt like a very good car. I heard that the stock shocks were bad, but wow, didn't know it is that bad. There are some corners on this track where there is a bump before the braking zone, or we need to use the curb to get a better line, this car just could not settle in time. The Mini Cooper S did a much better job in this aspect. I think the weak shocks also contribute to the lackluster performance in the transition stuff.

Lap times were quite disappointing. The fastest I clocked was a 2:01. Comparing to what I managed in the Mini, this is wayyyyyy off pace (+4 secs!) But it is too early to draw a conclusion. The Mini had better tires, brake pads, and, well, better shocks. And it is the first time we put this car on this track too.

We should have more after the next test day.

 

Maybe to help with the understeer problem, add more camber to front and get rid of the toe in in the rear?

And yes, the stock tires are horrid

FS

 

take out rear camber ...

 

Even out tire pressure f/r.

 

Totally agree with TeamRX8,

I cannot recommend any pressure change until you have some measurement on the tyre temp. I use a infrared temp reader, measuring all 4 tyres (center, inner and outer edge). Right Team?

I don't know the best temp for road tyres now, but the Jap in cold weather were happy with them being in the high 40s to low 50s Celsius.

I run R spec tyres (Bridgestone RE55S) and I need to work them to get some balance.

You will be surprised how much difference the alignments and tyre pressure make to the cornering of the car!

 

Yeap, I knew about the rear camber. Originally, I wanted zero toe and between -0.5 to -1.0 camber at the back. The alignment guy insisted on a more conservative setup for first track test.

The front camber is already maxed out (someone somewhere on this forum said it is possible to get even more by reducing caster?).

We will have different tires for the following tests. Let's see how it goes.

 

This is a decent basic guide:

http://www.nyracer.com/overunder.htm

 

you'll be hard pressed to get less than 1 deg camber in the rear especially after lowering it

 

Solution?

(My thoughts:
1. Use sway bar to compensate.
2. Use Shocks adjustment to compensate.
3. Adjust tire pressure.
4. Adjust driving style.)

 

I doubt you'll need to go below 1 deg, I'm probably one of the few RX-8 people who have run down around 1 deg

you need more front camber and you probably need more front air pressure especially with only 1.1 deg front camber, if the front tire corners roll over too much it will push bad

 

agreed.
34psi keeps front sidewalls clear of roll over mark on my setup (-1.2 front camber).
I also run 34psi in rear (-1.4 rear camber).
Setup is well balanced. Tail end comes out under throttle when needed. Doesn't understeer at turn-in and is neutral on throttle while tracking out.

Tweaking according to track temp and track surface is a must, so my numbers work as a decent baseline at the tracks I visit. I did see a hint of turn-in understeer at Sebring (due to concrete surface).

 

Turns out I will be running the stock potenzas until they cord. Wifey put a stop on tire purchase (...what's with wife and tires....)

I'll play with tire pressure and check with IR temp gauge next time....grrr.....

 

Get a pyrometer...IR only works on brakes and stuff...tires cool rapidly on the surface...and the readings will be off. The pyrometer checks the deeper layers of the tread...and will be more stable and accurate. I have both...and the IR will change from the time it takes to go from one corner to the next

 

S-03's are at closeout prices at Tirerack $129

 

Hmm, let's see:

1 sec faster
or
sleeping on sofa+tolerate make-u-feel-guilty-look+doing dishes and laundry......

Tough call.

She's amazingly assertive this time that I am NOT getting yet another set of tires...