Between the barrel and the caliper. Plenty of space between the caliper and the spokes, maybe 1/2" or more. I'm back on my stock wheels for the winter though so I can't take a picture any longer unfortunately. None of the big brake kits fit on the 17" RPF1's from what I've been told.

 

These wheels aren't the lightest in the 17x9" +48 offset (17.5lbs), but they claim they fit the RX-8 and there's a production run planned for Feb 2010. They also look sweet in matte bronze!

(15x9 6UL size shown)

 

Double post

 

...and neither tells us what wheel you're referring to.

 

If your going with a 17x9...Why not just get the RPF1 that is only 15.9 lbs...Unless your going to get a BBK, then it will fit just fine.

If your looking to get the BBK...it will be hard to find a set of 17's that will fit. Possibly a used set of CE28N's or RE30's will fit. You can find them for good prices if you look around

 

My bad. They are the 6UL's from 949Racing.

Fix0red!

 

The customer service rep from Enkei mentioned the first shipment of the new PF01's are due to arrive on 1/24/10. Depending on the weight of the 18x9 +45 PF01, I may go with those or the 17x9 +45 RPF1 or join the pre-order for these 17x9 +48 6UL's. A big brake kit isn't necessarily on or off of my list, but it definitely wouldn't be one of my top priorities. I'd rather upgrade the rear limited-slip than install a BBK quite frankly.

 

that's what i figured.

BTW...ran my first real autoX in an RX-8 (not mine). holy ---- that is a fun car, even on three-year-old Hoosiers. can't wait for the spring!

 

^Is Mark saying there is no advantage of a different rear limited slip.

 

*double post*

 

FWIW, I see two distinct advantages of the 6UL's over the RPF1's in the 17x9 offsets I'm consideirng: 1) Better caliper to barrel clearance 2) Better offset for an RX-8

At the end of the day, are these 6UL benefits worth a 1.5lb weight penalty???

I'm glad to hear you like the RX-8. I've never owned any car for more than 2 years, and I'm currently at that mark in my RX-8. However, I plan to be in this car for at least another 2 years...maybe longer!
At the end of the day, I'm doing research with an open mind and upgrading my car the way I see best. Good luck in your build #2.

 

The RX-8 has a Torsen, right? Have people complained of it being problematic when on-throttle mid-corner? I assume you'd move to a clutch type?

The SM2 S2000 folks I know seem to prefer the clutch-type, but they're also making a lot more grip, and so getting a lot more roll than we are.

I'd rather have a gear-type of some sort, as it'll move power rather than just limit wheelspin, but the big fat bimmers unload the inside rear wheel too much to make them work.

 

The 6spd RX-8's come with a Tochigi-Fuji lsd which acts like a Torsen in many ways. Lift a rear wheel and it behaves like an open diff.

If I upgraded my lsd, I'd go with an OS Giken (clutch type).

 

Interesting... That weight seems reasonable, but I am surprised Enkei has a set of the 18x9 +40's in North America. When I ordered mine in February, there was not a single set in the country. Is it possible they weighted the +18 model?

 

They only had one set in the country. They had the guy from the warehouse send me an e-mail directly with the weight. He confirmed that it was an 18x9 +40 RP03 that he weighed (w/ centercap).

 

Very cool. Thanks Chike. Maybe I'll take a center cap to the post office and see if they will weigh it for me (just for fun).

 

Well, with limited funds (4-5K), I've decided to focus my local STX build on the following:

• 17x9 +48 6ULR wheels
• 255/40/17 tires (undecided on brand)
• Adjustable swaybars (F&R)
• RB intake
• RB mid-pipe (with 100cpi cat & resonator added)
• Coilovers
• BHR GMC Yukon Ignition kit

Multi-time national champion Sam Strano (www.stranoparts.com) is helping me in my selection of coilovers for the car. While his prices are very competitive, he provides invaluable advice/input. I'll be purchasing coilovers from him in the next 3 weeks or so, and he's already spent an hour on the phone with me last week discussing my available options, target wheel rates, etc. I'd definitely recommend that anyone setting up an RX-8 for any class give Sam a call (he can get many products not listed on his site -- Ohlins, Bilstein, KW Variant 3). I know Fossum has worked with Sam for years.

I'm hoping to do at least the Peru NT in 2010. Beyond that, it'll just be local stuff for me.

 

The world of limited slip differentials is confusing.

Linky for the people who are curious:

http://www.houseofthud.com/differentials.htm#quattro

 

Sounds good! Good luck working with Sam - seems like a smart move on your part.

Only comment I'll make is that I made my 210 rwhp with a stock intake. Eric Meyers has also said the intake is woth very little.

 

Like others, I've been pondering the OS Giken, or perhaps a Carbonetic unit, but I'm not convinced an STX RX-8 needs a new diff.

Case in point, the CSP Miata folk seem to like the Giken a lot. However, those cars have huge grip and the top drivers are complaining of inside wheel spin using the stock Torsen, and thus see improvement from a clutch LSD. With street tires, the grip is lower and the inside rear wheel should not be unloaded as much as a *SP application. Not to mention the fact that our cars have a wider track, which again should reduce weight transfer.

I personally have no recollection of inside wheel spin problems on my car, but then I may not be driving it fast enough. And, perhaps there are other reasons for a different diff, such as the low-speed understeer problem?

 

Agreed George especially about working with Sam. I was getting conflicting advice from multiple sources and I thought it best to just work with one person (who has championships to back up his words).

Not expecting big gains, but I wanted to get it out of the way before I get a Cobb AP and a protune. I also plan on adding a header before the protune (minimal gains also), but I'm putting this purchase off for a bit longer.

I should also add that the BHR kit isn't a true STX mod as it's stock class legal. I just didn't get around to doing it until now.

 

That could also be due to your alignment being not as aggressive in the rear as others. I'm still up-in-the-air about where I'll start out. Based on my wheel rates and the suspension design of the car, I don't think I'll need a heck of a lot. I may go with -2F, -1.5R and monitor my tire temps and increase if needed (remember 100% of my local sites are asphalt).

I'll be researching the diff thing some more in 2010. According to an S2000 guy and a CSP Miata guy, they both spoke highly of the OS Giken (over a Kaaz and the stock diff).

 

True about the alignment. I'm running -2.5/2, with (I think) good temps & even wear.

Yes, the CSP guys like the aftermarket diffs, but again they are running 275 710s on 2000 lb cars. Our cars, in STX trim, have lower peak g's and a wider track, and therefore less weight transfer, which equals more weight on the inside rear wheel at peak g's, and therefore should have less of a problem with inside wheel spin.

At least, that's the theory. Next season, I'll start paying more attention to the car's behavior and see if there is a problem to address.

 

Very good points George. I'll feel my car out next season and see if I think it needs one as well. I also plan to have a few other drivers try my car (Shawn, possibly Strano, and a few others) and see see if they feel it needs a better diff. However, my main priority in 2010 will be sorting out my suspension (adjuster settings, ride heights, swaybar settings, etc).

 

Of course, the other variable here is the longitudinal grip of the tire, and street tires have less of this type of grip as well. So it just depends where we end up in our particular car.

I know Karl was having some power-induced oversteer issues in my car at the last NWR event, but I think that was due to the fact that he is not used to the power delivery characteristics of the rotary (and also likely due to some ham-fisted shock tuning on my part at that particular event). I'll ask him to pay closer attention & see what he thinks. As an Evo instructory he's literally autocrossed hundereds of cars, so he should be able to pick up on these sorts of things.