Back in January, I was searching for a set of Tein coilovers and came across a new range of coilovers due to be released late February - Tein MonoRacing, which sit between their existing MonoSport and the flagship, top of the range, SuperRacing. Spring rates are customisable from 12/14/16kg front, to 8/10/12kg rear, which seemed pretty reasonable so I figured I’d give them a try. Monotube design, the usual height and damper adjustable, and unfortunately like most coilovers, no individual rebound adjustment. I placed my order and opted for 12kg Front and 8kg Rear, and wait until the release date of Feb 22nd, had them shipped from Japan and they were in my hands 6 days later. I took some measurements, assembled them, then threw them back in the box and then they sat in storage for a few months lol
When I got my new Miata, I swapped out the Tein Flex Z’s that came with the car, fitted my new Tein Monoracing, and did the same with the wheels, with an exact same set I had ordered earlier. The wheels that came with the car were a few years old and slightly faded, but were still in pretty good condition. No buckles or rashes. I sold the wheels and coilovers to Stephen, I’ll let him share the details of what he wants to do with them. Anyway, it took roughly 3 months to get these from Japan, new RS Watanabe Type B 14 x 6.5” +14.5, with rim processing for NA8 brake fitment. For those interested, if you have an NA8 and want to run these wheels, it’s essential you get the rim processing done. At 2500 JPY extra per rim, they shave the rear spokes down in order to clear your NA8 brakes. Either that, or you run spacers, which I’m not really a fan of. You could theoretically just pay for processing the two front wheels, but I did all four so I could rotate wheels/tyres if needed. On the topic of tyres, these were a major PITA to get in Australia. No one carried stock and my only option was to order them from Japan, a nice long 4 month wait…. got them all fitted and balanced when they arrived and now they’re sitting pretty on the car. The Watanabes came with a set of lugnuts as well, but I sold them off to Vu, a NB owner who I’m pretty sure would be on here somewhere hehe
Initial impressions of tyres are quite positive. The tyres are extremely responsive! Sidewalls are pretty stiff, typical of Bridgestone tyres. I usually pump my street tyres to 38-40psi, depending on the tyre, and at 40psi, they’re still comfortable (must be because of the 60 profile). They have a 200 treadware rating, and are VERY stick tyre, maybe even too sticky haha. Much more sticky than the AD08R, but they don’t seem to be as noisy.. They’re constantly picking up small rocks and pebbles as you drive, so that’s slightly annoying. Driving over a freshly laid surface is even more annoying, the sound would be similar peeling masking tape off a roll, not sure if that’s because of how sticky they are or just the tread pattern. I’ve read lots of reviews and the one negative point that everyone makes is that they don’t last very long. With the long ass wait to bring them in, it would probably be best to order any replacements a few months in advance. I don’t drive my car much anyway so I’m not too fussed, so even if they last 8-10,000kms I’ll be happy. It will probably take me 3-4 years to drive that distance anyway. Here's a photo with a work colleague. I recently found out he imports containers from Japan for parts and cars, this might get interesting..
Anyway, back to the car.. one thing that annoyed me about it was the keyless entry / alarm system. Occasionally, the immobiliser plays up and I spend more time than I want to, trying to start my car. I have a feeling the dodgy alarm was contributing to draining my battery as well, but I barely drive it so who knows. Regardless, I think it was time to get rid of it. It didn’t take me too long, took my time and was done in about an hour.
Having eliminated the fuel odour in the previous car, I figured it would be best to be proactive and replace the same items in this car before it’s too late. Nothing worse than driving a car with the stench of fuel absorbed in all your carpet, trim and plastics. There weren't any fuel odour issues yet, but regardless of the mileage on the car, it is still 25 years old, meaning the rubber hoses are 25 years old as well. Our Australian climate is quite harsh, summer is hot and dry, and we have many days where the heat is above 40 deg C (105 F) . The fuel odour issues occur because the rubber hoses dry out and harden up, tiny cracks forming and basically the hose is dry rotted. This is probably where fuel vapour escapes under pressure. If you rub your fingers on your hose, it might pick up some of the odour. There have been reports of the one way check valve may clogging up too, forcing excess pressurised fuel vapour to find other ways to leak out; ie: the hoses. There have been recommendations to clean the valve out but I opted to just replace it. The most common hose that dry rots is the large one in the boot. When the Miata is filled up to its maximum capacity, fuel sits about half way up that hose, so it is essential you swap out all your components on a half empty tank, unless you want to deal with leaking fuel everywhere in your boot. You could just replace the large one but better to just replace the entire lot. Saves me the hassle of diagnosing any future issues.
All OEM items were used:
-Fuel vapour check valve
-Fuel rollover valve
-Fuel vapour hoses
-Fuel filler hoses (large and small hoses in the boot)
-Fuel pump sock + washer
-Fuel pump assembly gasket
-Fuel pump feed + return line
-Fuel filter + inlet and outlet hoses.
So here is the install. Fuel vapour hoses, check valve and roll over valve
Fuel feed and return hoses. These go from your fuel pump to your hard lines, feeding fuel into the motor. The return line is longer than the feed line by 1cm, and is actually discontinued. However, just order two of the feed lines, and it still fits perfectly fine.
Fuel pump assembly gasket, sock and washer. The japanese part number for the assembly gasket is discontinued. I used the USA part number, and it still fits fine.
Fuel filler neck hoses
All items replaced, rear deck wiped down and carpet reinstalled. Soft top also removed from car and i used a taped up coat hanger to clean out the soft top drain holes. A few bits of dirt in there, nothing major.
I’ve also read that the orange and black fuel caps are different, orange for cars 89-95, and black for 96+ models. I am unsure of what the differences are, but ordered the black one anyway for a more subtle look. It fit perfectly fine, and screws in the same amount of rotations and clicks as the orange one. When I remove the fuel cap, it hisses and releases pressure just like the orange one does, but I’ve kept my old orange one anyway, just in case I missed something. I will closely monitor the fuel system over the next fuel months to see if any issues occur, especially now as we are approaching our summer months. Maybe I'll send Tomoyo a message and ask her if she knows whats up..
I strongly recommend all NA owners do this overhaul, it isn’t cheap if you use all OEM items, but it really is worth every single penny. On closer inspection of the hoses, it seems the OEM hoses have white thread in the middle of the rubber.. not sure why, but probably the reason they cost 20-30USD each for the smaller ones, and 45USD for the large one in the boot.
I also handed back in the license plates that came with the car, and just replaced them with some standard issue plates. Complete custom license plates in my state cost 330 USD per year, in addition to 650USD annual registration costs. Definitely not something I am keen on paying for.
New plates mounted. I took ownership of the car at approximately 87,000kms, so I knew a 90,000km minor service was due soon. However, I’ve decided to start ordering all parts required for the 100,000km timing belt / water pump service to do early. Luckily I did because a few weeks later, I found myself stuck on the highway with a blown heater core hose. More on that in the next post…