I think we have the same dampers unless your 2812's are more different from mine. I'm actually not so sure that it was at full jounce, since I just jacked it up until it touched things, but it hasn't rubbed up top at all. I've only driven it at fairly smooth sites though. I do have minor rubbing on the bulkhead behind the tire though.

On my setup, the tire contacts the radius inside of the "L" of the control arm, so maybe your smaller wheel diameter allows it to stay in a narrower region of the arm.

 

my bad again, I thought he was referring to the wheel itself rather than the tire. So my thought above is likely wrong.

I have the very first set of 2812s ever made for an RX8 (early 2006) and they were built to my spec, pretty sure they are shorter than some of the others that were built later. Used to have a picture of the front at full compression with 10.5/265 fitted, but can't seem to locate it now. The camber gain was pretty crazy.

 

TeamRX8
I thought he was referring to the wheel itself rather than the tire.

No, you are correct- My 11" wide +45 causes the wheel inner lip to hit the front lower arm around full lock instead of the tire like Kennetht638 10" +38 as it is ~20mm closer to the suspension.

Kennetht638
maybe your (TeamRX8) smaller wheel diameter allows it to stay in a narrower region of the arm.

Ah, another nuance in wheel/tire fitment.


TeamRX8
just to summarize the sizes we have been discussing
Another bit to point out for trying to fit the widest tire is to show where the offset centers the tire.

18 x 8.0 +50, OE size, base reference for aftermarket wheel lip positions

18 x 10.5 +43 .... 38.50mm further outboard, 24.75mm further inboard
Tire tread width moved 7mm toward fender from stock

18 x 11.0 +45 .... 42.85mm further outboard, 33.10mm further inboard
Tire tread width moved 5mm toward fender from stock

18 x 10.0 +38 .... 37.15mm further outboard, 13.40mm further inboard
Tire tread width moved 12mm toward fender from stock

17 x 10.5 +56 .... 25.75mm further outboard, 37.75mm further inboard
Tire tread width moved 6mm toward suspension from stock

Kennetht638
When people ask me how much camber I run, I usually just say "all of it."

Yes, your tire tread block would stick 11mm further out than mine.

Offset moves yours 7mm toward the fender from and another 4mm from wider tread width.

So, you would require -1deg (11mm) more negative camber than available stock to clear the fenders as I do.

TeamRX8
My car has way more camber than yours

Great! Not sure why you had a problem with the fender edge then, but great for grip.

I still want to see an RX-8 on 15x11 with 275/35-15 A6s. Low car, light and short wheel/tire.

I guess you could get even lighter aftermarket brakes that matched the base model rotor diameter instead of downgrading to stock base brakes in Street Prepared.

 

I looked into 15's a LONG time ago so that I could run rally tires and even tried fitting one up at one point. I don't think you'd be able to do it in SP because the wheel runs into a lot more than just the brake caliper. For reference, here's a post from a thread about an RX-8 rally car that successfully fit 15" wheels. He says:

 

Someone ran a set of Bogart 16" on an RX8 with larger Sport OE brakes at Nats in XP several years ago. Doubt they will clear the aftermarket brake calipers though.

I considered the smaller base-size aftermarket brakes /wheels but wasn't convinced of the cost/value benefit. The 275/35-15 is 22.6" OD. Even with the steepest RX8 auto gear ratio of 4.30:1 would only get it to a 23.3" OD equivalent on the 4.444 gear. On a short course it might help, but you'd likely either run out of 2nd or be shifting between 2nd & 3rd a lot on most National level courses. If you do go faster you will also need to whoa from faster too. Not sure if the smaller brake area will cost more than you gain. It would be an interesting experiment. I just have too many other pans in the fire for now.

 

FWIW - Factory brake calipers barely clear my 17" RPF1s. I have to make sure the balancing weights are set away from the calipers.

 

That's just due to Enkei's spoke & inner wheel design. My Bogart 17" have tons of clearance around the RacingBrake calipers and the Enkei won't fit at all.

 

I hope all this port smoothing is worth it on the LIM, what a ****** luving PITA, one more session and it should finally be done, Olddragger would be so proud

The transitions into the individual primary & secondary ports seem really shrouded and abrupt, never really gave it that much attention before, hopefully smoothing it out doesn't shift the powerband up excessively, it's a ton of grinding to get it there



.

 

Apparently some people still think they can run a Mazdaspeed/AEM CAI or Racing Beat ram intake duct, but these are not Street Prepared legal due to a ruling on the NC MX-5 where we are not permitted to remove or modify the plastic cover across the front bumper bar:


RX-8 PART NUMBER:
56-181L F151-56-1Y1D PLATE,SEAL-RAD. SHROUD

 

just throwing this out there ....

 

Bold. I have been thinking about deleting the EVAP portion, but cutting through the actual UIM? Bold.

 

It helps to have a box full of manifolds, but if you look at UIM in detail there is a gap separating the two and I just took the jigsaw to it without any trouble. A vertical bandsaw would be easier if you have that option. Removing the EVAP assembly wasn't the bold part either. The flange removal is a different mod. There's more to it than just what you see ...


.

 

Bold is what you are intending to do. The cuts are just cuts.

 

we'll call it the enigma UIM mod .... regardless, I had to go out of state for several weeks to deal with a family situation so everything is on hold again ...

also decided to put off a custom radiator for now, plan is to reuse the OE radiator with a custom shroud/fan arrangement

 

Here's a pic of the 295 Hoosier with gouge, not going to get too far before that leaks or blows ...

 

Tire temp/pressure discussion moved on request to here: https://www.rx8club.com/rx-8-racing-...thread-253531/

 

Recently picked up a new set of 17x10 +44 Volk CE28RT Black Editions weighing only 16.5lbs.

Shown here with my collection.

IMG_7445 by Mike | Kuhn | Racing, on Flickr


Also finished First overall at today's event out of 160. By .832. The new 275/35/17 felt great with the new spring setup. Looking forward to Wilmington!

 

You have the weight listed for the standard face +45 version.

The +44 track version has a more concave face for BBK clearance and weighs more; 17.2 lbs each

Car looked well balanced, the driver maybe not so much where did you end up on rates? Never saw any dyno results?

I just got back from spending a month with my Dad and dealing with his passing. Not looking good for me to getting out this year, time and money are getting tight .

 

When I weighed them here without tires they were 16.5.

With the 275 Hoosiers that are 23 lbs on they came out to be 39.5 total with tires.

Rates now are 750 F 600 R. I seem to be getting a bit of inside wheel spin on corner exit though..

 

Dyno results were that disappointing?

 

We haven't dyno'ed it yet this year.

 

Ok then ...

 

I know and we were planning on it. Just ran into a few issues and I'm not going to dyno it until we get them fixed.

 

Eeek. Guess I am in violation

 

you're not the only one

not having the engine bay insulator panels installed is another one, as is having aftermarket side skirts installed ...