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Welp, I have no business in this
class given that this is my first autocross, but I'm running in DSP this weekend here in the Kansas City region. Mainly because when I bought my car, it had 9.5" wheels on it and I can't justify the cost of new wheels right now.
But honestly, I don't expect to be competetive in any class. I'm primarily looking for a place when I can drive my car at its limits safely and legally.
It'll be like playing a video game on "hard" mode, right?
So I ran my first event this past Sunday. I was the only one runing in DSP but I ended up about 5 seconds slower on all-season Potenzas than the fastest STX guys on sticky tires. They were posting times in the 49s and my fastest run was a 54.6.
Watcing the video and given that my last run was a 1.5 second improvement, I'm sure the car has much more to give the way it is currently set up.
Bryan if that was your first event ever Id say you're building off a pretty good foundation. If you dont plan to do any National events where youd get protested than you in all likelihood could just ask your local competitors to just let you run in STX until you get the wheels updated, no one minds until youre beating them all the time.
A really great driver on all seasons will finish strong midpack against guys on proper tires, they're really only about 2 seconds per minute slower, and thats with the new crop of extreme tires out there. So think of every run as an opportunity for driver improvement and try not to get frustrated theres till time to be found out there.
you could pick up stock sized wheels or 17x8 for pretty cheap and run in CS with minimal prep, that'd be a good place to start. DSP gets really fast and staggeringly expensive. I wouldnt recommend pursuing it yet
It's good to know about the roughly 2 seconds per minute because that gives me a realistic target to hit before I really need to consider upgrading my current 400 tread-wear tires. At this point, I know that I'm the slowest part of my current set up
I'm going to keep an eye out for a good set of used wheels but in the meantime, I'm going to keep running and comparing my times to the STX guys as that's really more in line with my car's setup.
As far as my actual current class - I'm not expecting to be competitive anywhere in my first season, so It doesn't matter to me, really. We're not on-track at the same time
finally, out of the back corner from 1.5 years ago and now with some elbow room the real work can begin ...
I love the smell of gear oil in the morning and no sleep before starting work OSGiken LSD shipping out for a refresh then getting slapped into a fully rebuilt 4.77 S2 diff ...
I'm making the jump from STX to DSP this year. Should have been in DSP last year seeing as when i bought the car i was catless, but other than exhaust and BHR coils there was nothing else done to it. I Picked up the JoeFis aero kit earlier this month and just got the spoiler on last night. Splitter will hopefully be happening sometime this week. Hawk HP Plus brake pads are here now. Still debating whether or not i want to "upgrade" the rotors to Hawk SP performance slotted ones. Seeing as i keep hearing that our stock rotors are pretty legit.
I can only determine one meaningful physical change between my original 2005 S1 rear suspension arms and the later S2 rear suspension arms. The rear tie-rod center tubes are approx. 0.070" larger OD and the resulting weight difference is obvious just holding them both in your hands. I recall the road racers complaining that the S1 tie-rods would bend too easily in minor wheel-wheel contact. So it was likely done to address this. Otherwise all the bushings, ball joint ends, lengths etc. are all identical to a tee
Another forum myth up in smoke ...
Originally Posted by TeamRX8
My rear suspension only has about 13k total miles on it, but being 10 years old I decided to bite the bullet and swap out all ten arms & update to new S2 parts
I think the Mazda parts guys need to throw a few more part number stickers on them ...
Without changing the arm lengths it seems unlikely. I considered an S2 subframe, but was kind of leary about buying one from a salvage yard due to concerns over whether it would be tweaked or not in some way. In my mind any geometry changes might correspond to revising the rear uprights. There is something different about the rear shock perch and rear spring positioning on the S2.
f'd off for over a year and now it's payback time burning the midnight oil
Wasn't sure I'd remember how to put the dash back together after tearing it apart 18 months ago, but it seemed to go well. So the radio and stereo components were all removed then, but I decided to keep the radio/dash cover plate for simplicity. If I need another 1/2 lb. weight reduction I'll make a custom cover, but the HVAC dial controls will have to be fitted to it since nothing in the SP rules says we can remove those parts.
Otherwise I finally got the race steering wheel setup installed. Was impressed with how rigid the ultra-lightweight drag race aluminum steering wheel was when I first received it. However, after mounting it up not sure if it will cut it or not. It''s fine for turning, but is not suited for any pushing/pulling motion forces. Might have to rethink that one. Essentially the wheel is now positioned back about 4" more rearward than the OE wheel. So no more cramming my knees into the dash to get close & personal with the steering wheel .... yaaaaay
Otherwise the components in the following pics are:
1. MiataCage.com splined & tapered Miata steel shaft adapter. Has to be machined/cut off to work with the spring-loaded extension from the front of the turn signal/wiper assembly. I have a non-DSC base model so no steering sensor. Might be an issue for those that do have DSC unless you disable it by pulling fuses etc.
2. Aluminum cover-plate to cosmetically fill the hole in the steering column cover face. Bouhgt it from McMaster-Carr and modified it to fit/bolt on. Super thin aluminum, weighs nothing, painted it flat black to match.
3. 2" aluminum 3-hole extension from Joe's Racing.
4. MiataCage.com quick release assembly.
5. MiataCage.com 3 hole x Grant 5 hole aluminum adapter.
6. RJ Max 13", 1 lb aluminum steering wheel
7. Hardware fasteners from Fastenal to make it all bolt together
8. Aluminum mounting bracket for AiM Pista display/dataloger riveted to top of steering column cover. This is sold by Mazda Motorsports for the Miata. Tweaked it some and it fits fine,
Steering wheel with quik-disconnect removed
SIde view, fully installed
Front view fully installed
Also some detail work to re-mount a few items resulting from allowed component removal, in this case specifically the air pump. So tidied up the wiring, found a new place to position the baro sensor, and also a custom bracket for the fuel pump low-speed/load resistor assembly.
Overhauled the 4.77 diff as a precaution. $180 for all new bearings, seals, and pinion crush sleeve from Mazda Motorsports. The local drivetrain shop charged $285 to tear down the original S2 diff, install the new parts along with the OS Giken LSD, painted the housing, bead blasted the rear cover, bead blasted the diff mount, and pressed in the RX8 Performance delrin bushings (already had urethane JDM bushings from STX previously).
Fully rebuilt S2 4.77 diff with OS Giken LSD and delrin bushings
I did get the thicker OE S2 radiator test fitted. Bolts right on like factory using the S1 hardware. Seems like you could re-use the OE fan shroud on it, but I did not confirm actual fitment since it's not my intention to use it.
Any way, off to Japan until the end of the month so everything will just sit. Things left to finish:
1. Work out front speedway sway-bar details
2. Rework fuel system; 2nd pump, wiring, all new flexible fuel lines
3. Rework/reroute oil cooler lines that cross engine bay - flex-hose with AN fittings
4. Fabricate new radiator fan/shroud assembly. Can likely use OE fan setup short term if necessary
5. Finish UIM/intake system.
Incredible attention to detail Team, your build seems much more thorough than anything I could cobble together with my time and budget :-)
I hoping to just make it happen with revalved Bilsteins, stiffer springs, 17x10's, a 4.777 and a good seat. :-) I feel like those are the big ones to hit and if nothing else the car will be fun to drive, I'm already removing and installing my wheels and tires(RivalS) in CS, so I figure I might as well be bolting on something stickier fi i have to go through the trouble.
So I guess I wont intimidate anyone with my half-assed build but at least the car will be fun to drive until I eventually get tired of being crushed by John Vitamvas locally.
Still in Japan almost another week before I can get back on it. Itching to get going on it now, but some of the upcoming work will be a little difficult. I'm taking time to clean things up, anti-seize on all threads, etc. as I go, so this drags things out some.
Looking good Team, can't wait to see it out this year! (Assuming I make it out there myself considering I need to spend all my money to rebuild the engine... ugh).
For anyone interested since this is the DSP thread, here is an article I wrote that got published onto Mazda's website. Might be helpful, might not. MAZDASPEED Motorsports Development
So I'm trying to put delrin bushings in my front UCAs, and I noticed that my UCAs don't look like they'll actually accept them if I press out the OEM bushings. Do I have weird arms? The rear bushing carrier isn't a full cylinder, so the steel bushing can sticks out into open air as shown (I already removed the inner metal).
Looking around online, I can't see other arms that look like this. They all look like this:
Was there a change made at some point? I think I'm probably just going to try to get all the rubber out of that can and make bushings that press directly into it, so I'd like to know if that's a terrible idea for any reason.
What year is your car? If it is early model, there was a TSB regarding cracking control arms and parts were updated. I took mine in to have them checked but there were no cracks at that time, so nothing was done. Later one broke at the track and put me into a wall.
04-07-2015, 05:20 PM
OSGiken LSD shipping out for a refresh then getting slapped into a fully rebuilt 4.77 S2 diff ...
I'll make a custom cover, but the HVAC dial controls will have to be fitted to it since nothing in the SP rules says we can remove those parts. 
