toolboy

your're staying with black?

fastlaneracing

Sorry for a late answer, it has been a crazy week at work. Trying to close out a 80Million SEK project quality wise (alot of overtime).

As im trying to find the perfect setup im going to share my setup and maybe get some pointers and ideas.

I like a car with as little body roll as possible (without being too stiff so the wheels will loose traction on ruff surface) and I want as little oversteer/understeer as possible. A perfect neutral performance is great!

Right now im running 18"x8" rims with 235/40-18" R888 GG and I go for 1,8-2Bar cold temperature in the tires and I try not to let them pass 2,4Bar in hot temperature. Agency Power Swaybars front and rear (both at looses setting), Agency Power End-links, Gtspec strutbars + Greddy trunkbar (i know its more for the bling effect) and KW V3 Coilovers.

Right now my car setup is not slammed, I try to have it as low as possible without getting the link arms sloping, Its corner weighted and tuned in quite good (only a few KG from perfect 50:50).

The Coilovers are in factory setting for damping and rebound.

I have alittle toe in back and front, 2 degress camber back and 2,5 degree camber front. The rest is like mazda suggest for their mazdaspeed setting.

Overall I like how my rex behaving, its dead straight in hard braking and guite neutral in balance for medium and fast curves. But if I go fast (little too fast, little forcing in to apex) in to medium or slow tight curves it can get a feeling of tripping on the sidewalls of the tires before getting good grip. If I go in with correct fast speed into slow tight curves I get stuck in understeer that only can be cured with tail braking for giving back grip to front tires.

The first problem I think can be cured with wider rims (as 8" is a little to small for 235 tire), That will make the sidewalls more in an inward slope and less change for flexing under heavy burden. This will also allow lower tire pressure (?)

The Second problem may be fixed with more camber and little toe out? This will also give more responsive turn in but also cause more instable breaking?

My thread wear is even over the tires (that indicates quite good surface contact overall?) right now, maybe I should be testing tire surface temeperature when in pit lane?

I hope I dont geeting you guys sleepy with all this

bse50

You should try to lower the tire pressure. try starting with 2.2 bars when warm and then step down to 2.0
Also try to play a bit with front\rear pressures. 0.2 bars more on the rear could make a world of difference fighting your understeer without having to play with the suspension angles during the day.

Anyway the rx8 is "designed" to roll, if you decide to make it stiffer you have to build the suspension from the ground up! Maybe its time to play with dampening and rebound settings

I like to have some more weight on the rear to reduce tire hop and have a balanced car during hard brakes. That's a matter of personal prefernce though!

fastlaneracing

I was little unclear I think, I try to aim for 2-2,2 Bar hot.

Havent tested different tire pressure front and back, that will be tested next time (only two weeks left) thanks for the advice.

About the roll, it still has roll of course. Our tracks here arent perfect so I dont want my car to break away over ruff areas and its still also a road car. Tuning in the coilover settings isnt easy so that will be the last thing when I get the rest as I want.

The company that helps me with my chassie did call me yesterday and I shared my thoughts about going for wider rims and he agreed that it would be helpfull and a good start.

So right now im thinking of going to 17"x9" rims with 235/40 R888 Tires that will also help reduce the high gearing.

StuttgartRX8

I'll make my comments tonight I have to work on my diffuser.

fastlaneracing

Im looking forward to that and don't forget to share pictures of your diffusor.

Are there any negative effects about going down one inch in Rim diameter?

rx 8speciale

iTrader: (3)

they are 20 pounds each and you wont believe the price i pay for all with michellin 235 40 18 tires 65% tread life left. the person who i bought them didnt want because he bought new ones, .

rx 8speciale

iTrader: (3)

somebody offer me to buy them already ,im gonna sell them and buy 18 staggerd wheels with chrome lip...

StuttgartRX8

The diffuser is still in design phase i have a 3d model of it made already. I'm just really picky right now with it, so I'll show pictures when I'm at a good point where I'm ready to build it. The First one will be made out of sheet metal for testing and then the final one will be carbon fiber for strength and Lightweight purposes.

I'm going with 17x9's myself I tried to get a set of 17x10's but don't want to wait til next year for them to finally come. The benefits of a 17x9 would be weight depending on if you bought a lightweight wheel. I read going smaller also helps with acceleration and braking. Negative it would affect your speedometer.

Example of weight difference:

Current Setup:
18x8 OZ Ultraleggra 8kg (18lbs)
Future Setup:
17x9 Enkei RPF1 7.2kg (15.9 lbs)
Stock Setup:
18" Factory Wheel 10.2 kg (22.5 lbs)

bse50

diffuser... uhm....
me wants!

StuttgartRX8

I'm sure a lot of people will want one.

bse50

Please mail me some prototype pics!

rx 8speciale

iTrader: (3)

damn i work tomorrow , my plans for today race wars and going tomorrow to the ring are cancel , they are pita lately were i work.....

fastlaneracing

Me too,

In some cases going up in dimension can lower your laptime.

Pros about larger wheels is, lower sidewalls (more responsive steering), More tire in contact with surface, more tire and lower tire temperature (more surface means more cooling of the tire).

But I think in our cases smaller dimension is more beneficial with lower wheel weight, I dont know if our brakes get less cooling with 17" ?

Smaller wheel diameter will lower the high gearing that RX-8 has.

Im planning to swap to 4.777 Final drive and maybe also swapping LSD in the same time.

StuttgartRX8

My cars not back together yet so I won't be there tomorrow. But I will be at Hockenheimring Thursday for there 2 hours of track time.

fastlaneracing

http://autopower.se/tips/default.asp the next table from botton on this page is really helpfull for calculating the changed gearing with different wheel dim. and final drive.

StuttgartRX8

That is really helpful

fastlaneracing

Stock wheels and stock 4.444

StuttgartRX8

Going with smaller will lose a little top end it makes sense.

I'm really worried about the rotational weight that's what I'm trying to decrease with going smaller.

StuttgartRX8

A 285/40-17 has the same ratio

fastlaneracing

Lower gearing will give more down low power, I think the RX-8 has too high gearing both for Swedish tracks and contryroads. Its only on highways its nice but thats a trade of I can take.

My previous car was an Honda CTR EP3 and that thing had crazy low gearing compared to the 8.

Do you guys want to share your chassie setup and wheel alignments?

StuttgartRX8

Thats funny I had a CTR EP3 also when I first moved over here. the type-R trannys always have low gearing they are meant for short tracks.

I would share my chassis setup but its changing completely here in a couple weeks.

fastlaneracing

Haha cool.

I really loved my silver EP3, that thing was really fun and easy to drive. It had rock solid quality and never ever gived me problems. Sometimes I miss it but the 8 is better in everything else as performance, handling, looks etc.

If you have time a would love to see your old setup and your comming setup as well with your comments about how the car handled/handles.

fastlaneracing

Where is it best to order Enkei RPF1 wheels from here in EU?

bse50

I wish they were sold in EU. I've never been able to find enkeis sold in europe!

I will share my chassis setup when it's over. Doing the last couple of modifications in these months.