The Forumula for RX8 Victory in STU Class Autocross

[Guest]

the spring rates given are when they are under load. they are progressive springs. without load they are 230 in the front and 170 in the rear. also, most springs are only about 10-30% stiffer then stock. like brian said, its the lotus approach.

most coilovers for this car has spring rates of about 450-550lbs/in. race rx8s are 800+. my buddies FD is running 1250lbs/in springs.

denward

[Guest]

I'm quite familiar with the various available package rates, but based on my own experience with the RX-8 that loaded rate combination doesn't make sense to me, but then it doesn't really have to either ... best wishes

[Guest]

BTW, the 18 x 9.5 Enkei RPF1 wheels are an awesome buy, kudos to Goodwin Racing for providing those to the RX-8 community

[Guest]

i aree that the spring rates seem "strange". mainly the rear. but ive called a few times and thats what they keep telling me. who knows? as ofright now, they are looking into why my car was lowered more in the back then in the front.

denward

[TeamRX8]

edited out, all sold

[tottoatol]

Had my first chance to try out the first 'mods' I've made to my stock sport-tuned 2004 RX8. The 'mods' were the Tokico D-Specs and a set of 8.5 inch SSR's w/ 245-40 Kuhmo MX's that Brian and G-W had off their 'old' setup.
First: With the D-Specs on full firm (minus just a little) all the way around and tire pressures at 38, the car was first and beat out 2 STI's by a couple tenths in STU on a pretty twisted (5 long Slaloms and a couple 'Ewa' boxes (as we say in Hawaii), but long (used about 3/4 mile of a 1.32 mile road course)...and about a PAX rank of 20.
In B-Stock however, an M3 (a well stocked one with 710's) beat me by about 5 seconds (70 vs 75). However...he was 2nd overall in PAX! The good side...I'm sure without the Tokico's he would have beat me by more than 6 seconds on this long of a course. The wheel/tire combo probably contributed some (28 pounds less than stock all around and a little more rubber), but the BFG g-Force T/A KDW-2's I was using are pretty sticky. The KDW-2's wear faster than the MX's (for my driving style)...but stick (showing about same G's on my G-Tech) the same as best I can figure.
Second: For the Club Trials runs the day before (no cones on a 3/4 mile road course layout with a couple hard 135 degree left handers, 1 off-camber), my best time was almost a second faster (42.0 from 42.8) than 'stock'. The D-Specs had the left sides set at 6 turns (out of 7) and the rights at 5 turns. Since the right front (and right rear on exit) was compressing and sliding pretty good on the sport-tuned shocks, the idea was to not unload the left so fast (keep the weight transfer slowed) and allow the right to bite in some. I didn't try any other combo's...cuz I was running better than I ever had! Not only was the best time a lot better, I had several laps better than my old best time. The average times over two 15 minute sessions (about 20 laps each) was about 1.5 seconds better than the old average lap times...on top of that...the tires were pretty much the same temps (read that as not sliding as much) all around. The rights were still a little hot after 20 laps...but I think I didn't start the pressures out low enough. I started at 34 and they were 42 on the rights (40 on lefts) at the end. The best times were from laps 5 to about 13.
Overall...pretty happy with the returns. (Now we just got to convince the state to keep the track open)
Aloha.
TR

[shinronin]

Today was our first autocross on our new Falken Azenis 275/35/18s on 18x9.5s all around with JIC coilovers and Racing Beat Sway Bars, Porterfield R4S pads, and a reasonably aggressive alignment....

hi brian, can you share what your alignment was or what it is now? i asked my shop for -1.75 f/-1.5 r and they could only get -1.1 f at most. my 8 is bone stock save for wheels/tires. if you know how higher front negative camber can be dialed in, please do share with the group. =) i wasn't expecting any difficulty hitting the front negative camber number given so many on rx8club.com have gone over -1.0. my car is still at the shop presently so if anyone can chime in that would great. thanks!

[Brian]

Quite a bit a variation from car to car in the max camber folks are getting. You are not alone in getting a max of only about 1 negative camber. Take as much as you can get.

My car has 2.2 front. We had 2.2 rear but that was too much (according to tire temp) and we backed that down to 2.0.

[shinronin]

Quite a bit a variation from car to car in the max camber folks are getting. You are not alone in getting a max of only about 1 negative camber. Take as much as you can get.

My car has 2.2 front. We had 2.2 rear but that was too much (according to tire temp) and we backed that down to 2.0.

can you explain or theorize as to what accounts for the variability in max negative camber any one car can achieve? this issue is a foggy one and there doesn't appear to be a good answer available on rx8club.com either.

[Brian]

You can line up 10 factory issued Rx8s and no two will be exactly the same height at all four corners of the car. The slight variation in car to car in height leads to a difference in max camber that can be achieved, and the skill level of the tech, and the alignment equipment he is using (measurement error) will also play a role.