elford_tim

Some more excitement - I changed the oil before the event and couldn't get the oil filter (Mazda OEM) to seal properly. Didn't notice that until I arrived at work in a big cloud of smoke. Oops.

So instead of setting off to the track in good time, I had a panicked oil filter change but at least the replacement held. Other than that the car was running fine, although I do still have issues with the rear tires slowly losing grip over the course of a session so I got to go sideways a couple of times.

Sign that the loose nut behind the wheel needs further work, methinks.

elford_tim

It's definitely time for some updates...

First, yes, I did hold the club's lap record in my class with this car. For one event, until someone competent showed up...

The brake issues dogged me through the rest of the season. I had to skip the last SCCA event as the judder got so bad it felt like it was shaking the car apart. That part we traced to worn hubs, so I had one of the few mechanics I trust around here install a set of new Mazda OEM hubs. While we were at it, we put new rotors and pads in the front as well, just in case. That almost cured the problem but under hard braking at Laguna Seca (where else), the judder came back. I'm planning to change the undertray for an aluminum one and once that's done we'll fabricate some backing plates and run some cooling ducts to the rotors in the hope that that'll finally fix the issue. I'm still a bit surprised by these issues given the reputation of these cars for having extremely strong brakes. Ah well.

One of the big issues I kept running into is that the stock seat is just too high for me to comfortable drive the car with a helmet on. Even when driving with a gangsta lean I'm prone to banging my head on the roof. To see if a better seat would fix this issue, I ordered a set of Nagisa Super Low seat rails for the driver's side. I've had these before on my MR2 and they're nicely made and basically do what it says on the tin.

First test fit looked pretty good, going from this:



to this:



However, for some annoying reason I always end up having to do this when I take a seat out of one of my (used) cars for the first time:

[img]http://mail.unix-consult.com/car/rx8-21.jpg[/img

Yup, one of the captive threads for the mounting bolts was fucked up so I ended up having to recut the thread both on the bolt and the captive nut.

Test fitting myself to the car was a success, I finally fit in properly with a helmet on my bonce. So of course I pulled the Recaro out again while I tracked down a driver's side seat belt buckle with its wiring harness. Call me lazy but I wanted to have a setup that allowed me to swap seats within a few minutes and not have to disconnect the seat wiring harness from the original seat.

Eventually I found someone who sold me this:



It's out of a car with cloth seats and no seat heater but that doesn't matter as the connectors are the same. I did turn the airbag connector into a pig tail with an "air bag simulator" aka a 2.2Ohm resistor:







Then it was time to fit the whole thing to the seat rail:



Needs a bit more zip tie action but it did the job. And finally I have a proper seat in the car:



I'm not a fan of running the seatbelt like this, so it's either time for a custom roll bar and a five point harness or time for another seat. I'm not sure which way I'm going yet - if I want to run Time Attack in SoCal in the Enthusiast class it'd require me to keep the full interior even with a roll bar, which complicates fabrication ($$$). The alternative would be to fit a Bride Low Max recliner instead. That's probably the cheaper option *if* I sit low enough with the Bride, if not it's the much more expensive option...

elford_tim

The other job was to replace the AST - as we all know rotaries don't like to overheat so having a plastic tank give up the ghost on the track isn't exactly conducive to the engine's health. Plus, a little bling under the hood is never wrong.

Time to pull this apart:



Apparently someone's been using my car as a storage unit while I wasn't looking:



Oh, and if you're too lazy to pull the air box tray out or just don't want to have to disconnect the wiring loom from it, a bungee can help:



Blingy test fit:



When I changed out the radiator I ended up replacing the hoses as well. I originally ordered the Mishimoto kit and found out it only included two of the three hoses, so I ended up with the Racing Beat kit as well. After I pulled the battery box and header tank I noticed a fair amount of wear marks and nicks on the Racing Beat hose so I pulled it out and replaced it with the Mishimoto:







And put everything back together:



Any excuse to play with the Flir attachment for my phone, sorry, I mean checking that everything it heating up properly:



It took a few attempts at burping the system but I much prefer this tank to the OEM one.

elford_tim

And finally, I had the airbag recalls done in December. IIRC there's still another recall lurking for the fuel pump mounting ring, but that wasn't yet current when I dropped it off for the airbag recall. Either way I'm probably going to install a new fuel pump anyway - there is no separate fuel filter on these cars and it's got close to 130k on what I believe is the original pump...

elford_tim

Aaaannnd...

Another recall. Sigh. I knew it was coming, dealer didn't know about it yet when I brought it in to get the airbags done and six weeks later I get another invite to bring it back.

Thanks to some pointers from Steve Dallas I found that Mazda Motorsports sells a front brake duct for the RX8 so I'll see if that'll help me fix the brake issues I'm experiencing.

Steve Dallas

Don't forget to post back and let us know what is included in the brake duct kit.

elford_tim

Well, that wasn't such a nice surprise...

The RX8 has stood for a couple of months since I've been traveling a lot for work and I don't use it when there's snow on the road. Over the last few days it's been raining so I was finally able to get the car out of its usual resting place without having to dig it out.

One twist of the key and it was running, as usual. Only this time it was only running properly on what felt like a single rotor and the low coolant light kept glowering at me. Eventually all chambers decided it was time to wake up and go to work, so it did smooth out. But given that the header tank is about 1/2qt-1qt low on coolant, that doesn't look like a good sign to me ().

Started fine warm on my way back from the lunch errands, but it looks like I'll get to investigate this particular issue before I decide if it's worth spending more money and time on this car.

Jeanator

Honestly I would just ditch the plastic overflow tank and periodically check the coolant level. FYI, there is no low coolant light when the sensor isn't connected.

elford_tim

I'm not quite sue I follow your reasoning - what would be the benefit of removing the expansion tank? After all, it does serve a purpose, namely keeping slippery coolant off the track if the coolant in the AST expands too much.

BTW, this expansion tank has a level sensor and thus can trigger the low coolant light.

Jeanator

I'm just saying I don't think it's worth it. I have the same pettit coolant tank and ended up not installing the plastic expansion. Wish I had bought the cheaper version.

elford_tim

Fair enough. In my specific use case, having the expansion tank offers a specific benefit (it doesn't barf coolant on the track if the pressure cap opens) but that's also because I like to run with the AST full like one does with the older rotaries.

Anyway, on to the continuing saga of non-progress.

I did some digging yesterday and couldn't find any obvious coolant leaks. Water pump is dry, too, and doesn't show any signs of failure. However, I found some odd deposits in the AST:





Those are hard, almost crystalline deposits. Almost like the deposits we get from the hard water here, but I mix my coolant using distilled water. My current working theory is that the PO dumped some Bars Leaks or similar into the coolant system to try and fix the leaky plastic radiator tank.

Anyway, I did charge the battery before firing it up again and it was running fine. I ended up topping up the expansion tank and let it sit idling for a while on our inclined driveway, then took it for a drive. Everything seems to be fine, it pulls fine to the redline and doesn't seem to down on power or pushing tell tale white smoke out the exhaust. I did notice that even after I returned from the test drive it was still burping air bubbles into the expansion tank, so I let it idle until it stopped doing that. If I'm very picky there might be a little more sideways movement of the engine at idle, but that might either be low-ish compression or worn engine mounts.

So far so inconclusive . I'll probably run the car to the airport a few times over the next few weeks and see if it's still using/losing coolant.

Steve Dallas

I recently saw that exact same thing in my mother's 2002 Toyota Camry. I bought it used for her about 3 years ago. I surmised that the old hoses were disintegrating from the inside out. My solution was to use the 25lb sledge and just replace everything. So, she got a new radiator, thermostat, hoses, and coolant. I never did find anything that looked to be the cause. All the old stuff looked good. But, we are 6 months on, and I have not seen any more of those deposits.

Some kind of Stop Leak product may cause something like that. Watter Wetter, when used with the wrong coolant, causes black and brown gunk and sludge, so that might be a candidate as well.

Steve Dallas

Hey, Tim, did you ever order that brake duct kit from MSM?

elford_tim

Not yet Steve, I spent this month's RX8 mod budget on an LRB undertray.

Brake duct kit is on the shopping list for next month.

Steve Dallas

Cool. After installing a duct kit on my Miata and seeing the very dramatic difference in temperatures and wear, I decided I need to do the same for my RX-8 by any means necessary.

R(ace)X-8

Thanks for sharing the saga...I'm engaged in my own, so it's nice to see other folks working through what it takes to track the car.

Not surprised about the brake judder being caused by the hubs - I was warned about these. The fact it still happened has me a little concerned. Overheating brakes doesn't typically manifest as judder - you get brake fade or boiling fluid. Maybe enough heat is transferring into your hubs and they are loosening up enough to judder? If that's the case, then the ducts should help - they are not hype, they really do their job well. If they don't help, you may still have bad hubs. =(

Last thought on that, the judder could be coming from worn bushings or a bad alignment...

Good luck and keep us updated!

Best,
-j