What setup is everyone running as far as tire size, front bar and shocks. Just trying to get a feel for what most are running before i change the car any more than it already is.

So far i have run with two different setups

1. completely stock other than alignment and 285 kumhos

2. drilled front bar, front koni yellow(waiting on rears) and 285 kumhos

 

Koni Shocks, street tires, stock sway bars. Hawk brake pads.

 

245 Kumhos, with Koni sports, Mazdaspeed front bar and alignment has worked well for me.

 

Stiff enough shocks to help out the weak axx springs, fresh Kumhos or Hoosiers (any size that fits the 8" rim) and an alignment...that's enough to bring it all down to driver inputs. The RX8 is set up agnostic in stock class.

...and I'm only partially kidding. I've driven Sipe's, Isley's, Caulson's, Jones', Goeke's, my own and a few more than I've forgotten about...they are within a pretty narrow bandwidth, imho, with most of the noise being the relationship between front bar used and alignment.

 

I was just curious what tires most people favor. I found a stupid cheap deal on 295 ho ho's. and was looking for feedback. I have a set of 285 ho hos that im trying next and also have 245 hohos and kumhos at my disposal

 

The 295 works very well, but there is a gearing disadvantage on the torqueless RX8 with the increased height.

 

Keep in mind this is on my 09 with the shorter final gear

sacha

 

Conekiller, I think you know my setup:
RX8 Type: 2009 Sport
Shocks: Montons
Swaybay: Mazdaspeed non-adjustable
Tires: 255/35-18 Hoosiers

 

Solo,

have you tried any of the other tire sizes on your car or did you go straight to 255's

 

damn... how much tire can you run on an 8 inch wheel...

 

You will find that most b-stockers will run 245/35/18,255/35/18,285/30/18, or 295/30/18 on n 8" wheel

 

I used Kumho 710s 245/35-18 on the 09 RX8 and my 05 RX8. I have been using the Hoosier A6s 255/35-18 and they are faster then the Kumho 710s. I never tested the 285 or 295 A6s but everyone I have heard from that has tried wider sizes say they are slower. In fact Wood Rogers in the latest Grassroots Motorsports Magazine (Aug 09 page 126) has a tire test that answers your question. He uses Chris Harvey's 06 RX8 to test Hoosier A6 in 255/35-18 and 285/35-18 sizes. Guess what the 255/35-18s are faster. In the press release (see 11/10/08 release) that Hoosier put out, Hoosier states the new 255/35-18 size was made for the RX8 with 8" wheels.

 

Thanks for that link Keith. Very interesting.

Btw, GRM articles FTW!!!

 

Solo,

I did just rear that article in grass roots and though it was very interesting. I definitely think that once its time to actually buy a new set of tires i will go that route. So far i have tried the 285 kumho only, i have another local in 2 weeks that i will be trying some 285 hoosiers on the set of ultraleggera's that i just picked up from georgeh. I should also have my rear koni's back today and that will another piece to the puzzle. Ill let you guys know how the car feels after that.

Sacha

 

Coming to Nats Sacha?

 

Woody (John Rogers) and I have continued to experiment with set-up and the 255's over the Spring. We have run several events with 285 fronts and 255 rears and finally corded our first 255 after approximately 80 runs. (One flip, 80% on the rear of the car). We went back to the 285 fronts primarily for the tread wear advantage and the small amount of mid-corner out grip advantage we noticed in the test. The downside is slightly less precision through transitions as we noted in the GRM article.

IMHO - The "fastest tire" still comes down to driver preference (confidence) and the course design on a given day, highly transitional courses will favor the narrower tires, big sweeps lean toward the wider tires. 245/255/285/295 are ultimately very, very close in performance on the RX8.

Chris H -

 

Are the Motons legal in Stock? I thought I read that they weren't (although what I read wasn't clear as to why).

 

Chike,

Not this year, the last time I was out there was in 2006 when my co-driver(greg hahn) and i both trophied in astock in my s2000. Plans are to run some national events and nationals in 2010

Chris,

I think ultimately you hit the nail on the head. I think it depends on driver preference and driving style. Most people who like the crisper turn in will like the smaller tire, while those of us who arent quite so smooth will prefer the larger tire. The 09 with the different gearing changes things a bit as well

dmitrik4,

the motons are legal as long as they are setup properly. Solo can comment a bit more but from what i understand its the same issue that us koni users are having which has to do with the rear perch height being different on the 09

 

Not to derail... However, if I didn't worry about staying in B Stock, would it be advisable to replace the springs? If so, should I pursue a particular brand?

I've been autocrossing my mostly stock RX8 for about 18 months. I run street tires only on 17x8 wheels. I plan on getting Koni Sports soon plus the Progress Technology sway bar, but was on the fence about springs. Also, note that I mostly run on relatively grippy concrete.

 

No stock-style replacement springs currently on the market for the RX-8 are stiff enough for our autocross needs. I'd hold off on getting the Progress swaybar and just get the koni sport shocks and get in on the Fluid Motorsports group buy for Progress springs. These springs will work with the konis (no need for a revalve) and the rates will be stiff enough for our needs (425# F, 280# R iirc). Once you have the shocks and springs on the car, I'd then consider making changes to the swaybars.

Btw, the group buy thread is in this Competition section of the forum, but lower down the page. So as to not derail this thread, maybe post questions in there.

 

THe Motons are legal as long as they are set at the same spring perch height as the stock shocks. My Motons were made with longer tubes than the Motons for the 04 to 08 RX8s, for the 09 RX8. Also you have to use the stock springs and stock upper spring hat. So you are only using the shock and lower spring perch of a Moton coil over. You also must use only the two way adjustable shock (Club Sport) not the 3 way or 4 way Motons. In addition you can't cut any metal to get access to the rear shock top rebound adjustment. So Bill of Small Fountain Racing made up adjuster cables so I can adjust rebound.

 

not sure where you got that idea, but fail

you can cut metal for the remote reservoir hose, but not for shock adjusters, the shock adjuster mods are limited to interior trim panels only i.e. the cosmetic trunk side covers, but not the metal chassis, we just discussed this in another thread recently

 

All true, if anyone is interested you can download the 2009 SCCA SOLO RULEBOOK and goto rule 13.5

 

After seeing one run this weekend, I think I might go for a 370z w/ motons or penske or koni 28's.

 

Anyone good behind the wheel of the 370Z?