In this episode
I love it when the plan comes together. The ticking noise from last month has gone, I’ve sorted the coolant hose, pulled out some insulation from under the car, went to Thruxton and practiced attacking Church corner. We had a puddle in the garage but what caused it? I’ve insured the car again. Frankly I love this little NC, on track it is so much fun. Oh and I remembered to reset the suspension for the journey home 👍🏻.
Tick ,Tick, Tick, goes…
This month I replaced the missing coolant pipe bolt and thread locked both bolts securing the coolant line that runs alongside the cylinder head. I’d lost one and nearly lost the second last month and fortunately it was noticed by someone with a good eye for MX5 engines who wandered into the garage for a chat and spotted it as they looked at the engine.
The good news is the ticking noise has now gone as a result. So a lesson learned there and I’ve added a bolt check for this item to my pre track day checks.
As I was messing about with the car I also pulled out the old heat insulation material that is located in the transmission tunnel over the gearbox. This had worked itself loose on one side and was beginning to hang down under the car. It’s made from a foil outer, insulation fibre middle layer and cloth-like backing. The years had not been kind to the middle fibres which had become powder-like and it had ripped clear of the fixings on the drivers side.
It was a bit of a faff trying to remove it by work it through the gap between gearbox and cross braces but once the fastenings were loosened and with some patience it can be worked free. It does require a mask and goggles to keep you safe from the debris and dust that comes with the whole process, but it is do-able.
I’m not sure I noticed much difference in heat or noise in the cabin as a result of this change on a track day round trip in the car this September.
Comms
I also temporarily fitted the new replacement intercom and headsets in the car. They really improve comms when we remembered to turn them on. They are perhaps a little tinny in sound quality but certainly loud enough and clear enough. I’d not connected it to the power supply from the secondary fuse box, so we were on battery power and the 9v rechargeable battery lasted until lunch time before needing to be replaced for the afternoon session. I’ll power them up properly in the off-season. But again I heartily recommend them.
Since I’ve fitted them I’ve noticed them in use by the pilots of various Lotus 7 clones, and open cockpit vehicle, again to mitigate background noise and improve comms, so I’m in good company
Thruxton track day
So it was back to Thruxton for another session. I followed a carbon copy of my route last month driving down to the petrol station to fill the car and the petrol can with 99 octane and off down the motorway. No ticking noises to be heard.
Tyre choice remained the Yokohama’s on Fox FX04’s (see previous posts). This was not without a little trepidation as the weather forecast changed from fine and sunny to cloudy and possibility of rain. The drive in was marred by foggy and rainy conditions and I was scared that the conditions would expose the AD08’s alleged vulnerabilities.
We made it to Thruxton safe and sound and parked over by the main building and checked in, this time there was a fair old queue as the WiFi was playing up. Some quick checks of our driving licences and confirmation of our disclaimers and we were given our wrist bands and car sticker.
It was then over to the Parc Ferme area where we joined the queue for exhaust volume noise testing.
As expected the car passed the noise test at 84dB ( it usually sits between 81 and 84dB), and then we drove over and parked up in the garage we’d booked for the day (see header image).
On this occasion we were meant to be sharing but the person didn’t turn up so we had the whole thing to ourselves, what luxury.
The plan
The plan for the day (other vehicles permitting) was to practice attacking Church corner harder than before in order to carry more speed through that corner and down to the final chicane. I’d been lifting as my brain told me the adverse camber would spit me off.
It’s really funny how you can think you’re going faster but events elsewhere slow you down, but the car was pretty good and I managed to keep the car between 93 and 97mph at the apex of Church, though this was often still with a slight lift on the approach (see image below and see difference between peak speed and speedometer). The link to the full video of these laps is below.
So there is still room for improvement and I’d like to learn to have the confidence how to be accelerating through church with the car balanced before and not lifting to tighten the line. I think this would see me then at 100+ and increasing all the way down to the chicane. Once that’s done I can turn to Allard to Campbell.
Retrospectively, both of us improved our best lap times with my best improved to 1.43.387 from 1.44.172 on AiM data monitoring in the afternoon session also with an improved terminal velocity going to the chicane. Speeds also improved in the run from the Complex to Church.
With both drivers improving their lap times and showing evidence of driving the track harder over last month session it would appear the suspension improvements and chassis stiffening seem to be bearing fruit allowing us both to have more confidence in what the car will do and how hard we can push.
There is still room for improvement and scope for the car to be pushed a little harder. I was watching the videos on YouTube by @jp__fox which shown faster lap times and so next time out I’ll be looking to spend a little more lap time at 100mph+ down that back not-so-straight.
One of the things we noticed when the car was standing in the garage was a puddle and two spots of oil on the floor. Coolant was the first thought given the previous issues in this area, but the coolant level was stable. Rain run-off from the journey in – possible, as was condensation from the air-con. The oil is a tiny drip from the diff. The water turned out to be run off from the windscreen when then washers were accidentally used turning the wipers on prior to the morning runs – doh.
We topped up with two gallons of petrol for the journey home. At the moment we’re using about half a tank of fuel purely at the track. Fuel economy is about 35-40 on the drive in and about 20mpg
Lap 4 things improve and I get my best time so far at Thruxton.
Is the Mk3 the expensive option?
All in, I’m still loving the Mazda. It’s a nice driving environment, comfortable on the road and good fun on the track. I was talking to the people in the garage next to ours and they were telling me that they had sold their Mk3 and bought a modded Mk1 because the parts were less expensive than an NC and there were more modding options.
I’ve not really thought about this before. I do know that most of the Lotus & based kits use NA & NB parts rather than NC parts. The person I was talking to said he thought this was because of the time the earlier models have been in use.
It seems to be the case that the more intensively modded, more track-focussed MX5’s at Thruxton seem to be Mk 1’s & 2’s. I don’t know if it’s more expensive or not. I only know at the moment it’s good enough for me.
