I haven't converted one because my car is a base and came with the non-DSC unit, so I'm probably not the best person to ask. However, I believe there is some wiring difference (the non DSC unit is essentially a standalone unit, it just needs a power source and wheel sensors - I know a few people who have added them to non-RX8's). The brake lines are the opposite flare, which would be annoying but doable. I accidentally ordered a replacement hardline for a DSC model and found that out the hard way and had to re-flare it to install it LOL.

 

guess I’m facing the same thing in another RX8 then, it is not going to be any easy conversion based on this thread, but possibly do-able with enough time, effort, and expense

https://www.rx8club.com/rx-8-racing-...sabled-267656/
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ok, maybe not so difficult to swap in a non-DSC ABS module after all, see half-way down this post

https://www.rx8club.com/non-rotary-s...3/#post4721664

however possibly not permissible in STX without switching out a large part of the wiring harness, aside from just buying a non-DSC car from the start.
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https://www.rx8club.com/series-i-do-...7/#post4953387


the key to it will be acquiring the connector/pigtail for the non-DSC module. It’s off the main electrical harness on the LH side of the engine bay. It’s not readily available, or rather I haven’t been able to locate it myself after some considerable time searching.

I’m going to submit it to people who specialize in that sort of thing though. It will likely cost more than a used abs pump/module going that route though just to have the bare, unwired connector.
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After driving a local DSP car on stiffer springs, I swapped springs to 800/600 from 12k/8k spring rates, as well as disconnecting the rear swaybar. Not sure I'll get to test this year though. It rides better on the street and still feels really balanced on the street, not that you can even remotely push hard enough in a safe way.

 

At 13k/10k with disconnected rear sway, the only time I felt like too much spring might be an issue was at ripken going through slolom and having to go over a crest right before off camber sweeper. Felt like with a little more compliance, could have been back on gas sooner.

Other than that, it's been golden. Comfy enough on the street and clearly more capable than my driving ability. I clearly need more rear camber than the 2deg the seized rears are limiting me to, something to tackle in the off season. Not sure about the fronts, but I plan on trying 4deg, up from 3 currently.

Question for the crowd, how low is too low? And what exactly is the issue as height goes down. Heard the suspension geometry thrown out there, but what exactly about the suspension geometry?

 

I had issues at that spot too, but I could definitely get back on the gas *hard* there as the car settled. I am mildly concerned that the spring rate changes will hurt power down even though the steady state balance will remain about the same.

I've got -3.8 degrees of front camber and I'd really like more to help the tire wear, so I suspect I'll be doing the offset knuckle bushings. I have -2.5 or so rear camber and the rear tires are wearing evenly.

I'm at 4" pinch weld height on 245/40R17 Yoks all around to try and get more camber without dealing with the offset knuckle bushings. It scrapes on the speed bumps where I live though which is fairly annoying... Otherwise, the rear end gains a lot more camber than the front as you lower the car, so you get into an even more undesirable part of the rear camber curve as you get really low.

 

Your car does look pretty low. I thought it was maybe the side skirts that made it look lower than it actually was. Not sure how 4" pinch weld translates to hub to fender, but that seems pretty low. I'm at 13.5" hub to fender all around. Not sure how much lower I can go in the rears, I may be out of adjustment on the coilovers.

At 2deg in the rear, I have some additional wear on the outside of the tire. I was wondering if 2.5 would be enough to counter that. I do have a hint of toe in as well, but very very little. I don't think that is playing too much into uneven wear. Still got pretty good life out of the Yokos. I need to do better at keeping track of number of runs, but ballpark would be well over 120 and still good life left....for dry events.

Other things I learned this year:
- Leaning out fuel using versatune really woke up the car. I have no clue where I am as far as how much, or little, power I'm making, but my autox results started showing good improvements post playing with fuel delivery.
- Need to do something with my steering wheel, it's too far from me.
- I need to work on sloloms more. I feel like I haven't adapted to how to do this well with this car. I don't feel like I can do it the same way I did with the Miata. Just doesn't feel the same.

 

I'm at 13" hub to fender up front, a tiny bit higher rear, like 13.15"

I have 0.35 degrees of total toe in rear, seems fine.

We're seeing like 120 runs until the yoks look pretty bald but they're fast until they cord.

I also saw huge gains by leaning out the car. Same complaint about the steering wheel for me, I was really tempted to order a hub extender but Amy is already jammed into the steering wheel. Same complaint about slaloms for me, the car is just... big. It's a lot more work to hustle it through a slalom than my Miata.

 

I made a spring rate change from 672/448 lbs/in to 800/600 lbs/in (front/rear) after the last Philly event. It was a huge improvement in ease of driving the car, so much easier to place the car now and it even rides better on the street. I need a little bit more front bar, it was pretty loose (especially on exit!) and my front bar is maxed with the rear disconnected. I'm upgrading from Hotchkis RX-8 front bar to Progress Tech, the bar rate change should mean I'll be towards the bottom of adjustment on the Progress Tech so I may add a little bit of rake to balance it

Yoks were really BALD but we did well. Fastest STX car and just about fastest <400hp car at NNJR. John V's car dominated PAX with Evan Schickel at the wheel. Clearly his changes have worked well too, haha.



My fastest run:


Talha's fastest run:


Interesting side by side comparison of us. I made a bit of time on the first two sweepers then Talha made it back in the big slalom. I was a little bit out of position for the sweeper after the big slalom putting me out of position for the final turnaround but it wasn't worth more than a couple of tenths.

 

You guys looked good, Ken.

My car is better with updated valving in the shocks, but we were struggling with a few things. Couldn't keep any heat in the A7s, it wasn't until Evan got a few runs back to back at the end that he really started to get heat in them. We were fighting a pretty bad push from corner entry through mid-corner. I'm going to try swapping to the OS Giken diff fluid to see if it softens up the decel lockup characteristics. Probably should have added some rebound damping to the rear shocks / taken some out of the front to see if it turned in better, but we were barely getting ourselves turned around to not miss runs as it was.

I'm at 1000lb/in F, 800lb/in R springs, Splined 0.188" front bar about 1/2 stiff, stock rear bar. Thinking I'll add some rake to the car and try that. Need to work on the traction control as well. Fun fun.

I didn't drive well, I guess I'll blame getting up at a quarter to 4AM to get to the site on time.

Evan's best (clean) run

 

Yeah I had chatted to Evan, sounded like you guys just had some pretty bad push. Your car definitely just looks mega stable versus mine, almost numb/dead. Surely not helped by the lack of tire heat! Rear rebound definitely sounds like the first step as the spring/bar combo should be pretty loose unless the aero balance is messing it up.

What did you think of Evan's car? Except for the power (mine is massively quicker for some reason), his car felt fantastic when I drove it and I'd imagine the OS Giken helped a good amount.

 

It feels too me like my OSG diff is completely locked up on decel. which is odd given it's set up as a one way.

Evans's car felt great from a balance and responsiveness standpoint. Lacking in power, obviously, but also lacking in ultimate grip. I think his tires are pretty old.

 

With the RT660 and V730 working pretty well pinched, is 265/35/18 on 18x9 still a competitive option? Seemed like years back this was a hot STX setup, but i'm not sure with today's crop of tires. So the question really is a 265/35/18 RT660 on 18x9 competitive with say 245/40/17 A052 on 17x9? The former would last WAY longer and be much, much more tolerant to heat.

 

you mean other than it being a taller and inertially heavier?

and why would you do that rather than 255/40-17 even …
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If you end up going this direction, we will have to swap wheels for a few runs and find out.

 

There are folks who like stretch and match the tire to the maximum wheel width (i am generally one of those folks; don't like pinch), but then i talk to plenty of people who say "for autocross, stuff as much tire on the legal wheel as possible, even if it means a taller and heavier setup". Seems like testing is the only way to really answer, and i'm wondering if anyone has done a 245 or 255 on 17" versus 265 on 18" test with recent crop of top tires.

regarding 245/40/17 vs 255/40/17, with the A052 liking stretch, 245/40/17 on 17x9 seems to be the hot RX8 and FRSBRZ STX setup locally. i'm running the 255/40/17 kumho V730 and it's a decent setup and previously ran 255/40/17 stones.

i know this is a "it depends" situation, on the nature of the course. I'm just wondering if the fact that i'm seeing mostly 245/40/17 on 17x9 means it is THE setup to have, or whether it's cheaper and works on our courses better.

it seems like a 235/40/17 could even be the ticket on courses with lots of acceleration but not high top speed, whereas perhaps a 265/35/18 could win out at courses emphasizing sweepers?

 

you’re splitting RCHs maybe, but if it is then it will be the A052 in that size

so still maybe off-point more or less if the intended goal is to be competitive

there are few courses where the rpms are not up and down, and if you’re splitting 10ths, 100ths, 1000ths of a second then the lower the gear the more it matters

that always assumes the driver is getting all that’s available, which some people then like to blow off as somehow not being all that consequential because the driver matters more

I’d be more inclined to run the 255/45-17 on 9” myself

Which I’m assuming the Yokohama USA website must not be correct, because it shows the 255/40 being lighter than the 245/40 by a pretty good amount



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vs 24.5 lbs and 25.4” OD for the 265/35-18

there’s also the 255/35-18 at 23.6 lbs and 25.1” OD

the issue with 18” is the wheel is almost always going to add inertial weight over 17”, but then this is the perspective from someone owning a set of 14 lbs each 17x9 wheels

20+ lbs of tires and wheels is not something I’m inclined to ignore on our torqueless wonder engine … even though I’m not as motivated about it being on my wasteband
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Using anything other than an A052 for STX seems like a waste of time. Cost per run is way cheaper on the A052s since you can keep the shoulders alive with the proper camber.

 

^^^ and people accuse me of being too blunt and direct

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I need to get around leaning out my car as well. Here is what stock tune looks like at summit point main with IAT @77F. What is the safe AFR for track/HPDE setting these days on S2? Between 12 and 13?

Full session AFR chart:



Here is AFR down the main straight 4th and 5th gear, braking zone for turn 1 and then turn 1 to turn 3 in 3rd and 4th gear:

 

TireRack puts the 255/40R17 at 23lb. For fun, I checked the RT660 in a 255/40R17 - 27lbs!

 

What program are you using to display the data?!
Those AFR's look like my old S5 N/A with upgraded fuel pump, I'm sure pulling some fuel would wake the car up quite a bit. Not sure about the Renesis, but I kept pulling fuel (Apexi SAFCII) until I was at 13.5 AFR at the leanest and tapered to about 12.5 by redline. Car seemed a lot happier than running the 10.5-11.5 AFR the stock tune.

 

the S5 or any previous 13B engine has no relevance to a Renesis

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I am getting ready to start my first season with the RX8 and will compete in STX, so I need to read through this thread, but for now I have a quick question I hope someone that frequents this thread can help me with.

The car I bought already had swift lowering springs, Bilstein shocks, and racingbeat sway bars. When I purchased it there where quite a few clunks in the front that I Identified as the end links. So I replaced those with some delphi end links and ever since there has been some squeaking coming from the front. This week I put on new pads and rotors, sway bar bushings and a few other items, and noticed there is slack between the front sway bar and the end link stud. Which is causing the squeaking sound. Does anyone know if the RB sway bar just has larger holes than are necessary, or if there are certain end links that need to be used on the series two that have a properly sized stud.

Thanks.