mx5trackdayproject.co.uk

Category: The Car

These posts relate to the development of the car

  • Thoughts on Development Direction

    Thoughts on Development Direction

    Introduction

    So the recent mods (see previous posts) are all in the car and have been tested at a shakedown at Thruxton Circuit in blisteringly hot conditions. In this post I review the work this far and how this has shaped future thinking for the car going forward. There’s some YouTube links below which show full runs at Thruxton.

    IL Motorsport Chasis Bracing

    In my New Bracing Goes In post I said that I was hoping to improve the rigidity of the chassis having notice some kick when changing gear under load having installed stiffer suspension.

    I can honestly say I didn’t notice any kick on the drive in (though this was pretty gentle) and not on the track so I’m going to say that adding the IL Motorsport Cross Brace and Rear Suspension Brace have improved the handling of the car.

    I was definitely pushing my limits further than before and my pace improved over my previous outings.

    BC Racing DS Coilovers

    I love these, they are a definite improvement over the old worn out Bilsteins. That is not to say I would not have loved new Bilsteins, which I did in my younger days on a different more rally-orientated car; or any other make of coilovers for that matter.

    When I drive on the road with softer settings they are comfortable in that role and when I set them much harder on the track there is less roll than before and there seems to be tighter control at higher speeds. On this occasion I drove in with them set at 1 click off softest, then started the sessions at 5 clicks from hardest in the morning and 1 click from hardest in the afternoon. I accidentally drove home with them set at track hardness and frankly it was not pleasant so note to self – change them back before loading the boot; and a learn from the experience.

    My spring rates are the 6 front and 4 rears which is the BC Racing recommendation for MX5 NC’s. I noticed at Thruxton that where I was pushing the car much more than on previous runs I was getting more roll than I had anticipated in the harsher corners like Campbell, Cobb and Segrave, which made me start thinking about anti-roll bars as a future option.

    The car was splendid through the chicane at Club so as I’ve already said above, I’m really happy with this choice.

    I’m not drawn to the idea of upping the spring rates yet (c.ÂŁ200) as the ride for road use is pretty good at the settings described above. I don’t really want to add harshness given my Grand Tourer objective, though this would change if the car was to become a track-only tool but I’d still need to upgrade the ARB’s anyway.

    Thruxton 2026 07 07 i

    Yokohama AD08RS

    These are the newer road legal spec and sometimes get battered for not being as good as the old spec. I’d pretty much decided that I wanted AD08’s as the start point for my track-focussed tyre choice.

    Since I’ve got them I really like them. My standard road tyre is Dunlop Sport Max which is a pretty good track day tyre for wet conditions. The Yokohamas were part of a tyre & wheel package from Wheelbase last year.

    On my last trip to Thruxton I did notice that the tyres protested the treatment they were being given by squealing pretty regularly on the tighter corners but the handling remained strong and I was doing 12 lap runs. I did trip the DSP once or twice when pushing harder than normal. I’d have no problem getting them again but I have not yet tried them against anything else.

    If I could afford them when the time comes and if they were available in my wheel size then I’ll try the Avon ZZR’s recommended to me by a very fast MX5 owner I met in June who raved about them, though at c.ÂŁ260 each for the Avons and half that for the Yokohamas that’s a couple of Track days so we’ll have to see what the budget will allow.

    Fox FX004 Wheels

    These Black 17 x 7.5’s are shod with Yokohama AD08 RS215/45/R17 came from wheelbase as a package and frankly I think they look fab .

    I don’t think they were a weight saving choice (Budget wouldn’t allow), but they look mean and that’s got to be wort 1-2 mph. EBC Yellow Stuff Brake Pads on standard discs and calipers

    Parked up at Silverstone Old Pits Paddock

    I love them they work well for me, though for the first time I noticed that they get better with a bit of heat in them. With good braking point selection they hauled the car down to

    BBR GTI Catted Manifold, Centre Pipe and GT Rear Box

    Again I love it it burbles nicely, makes a good noise when up and running and the car either is faster or feels faster. I added a Versatune standard NCU package ECU flash as a stop gap until I can get it on aRolling Road. Again Ive not been disappointed despite the cost.

    I fabricated a heat shield for the rear of the alternator until I can be sure the heat generated by an unshielded manifold won’t damage the black plastic ?? vent to channel cooling air into the alternator.

    Thruxton 20260707

    So Where Next…

    As the car does not over heat despite 30+C at a fast track where the car is up near maximum revs for a lot of the lap I’m not thinking an Oil Cooler is necessary at this time and have removed that from my development plan for the time being.

    I’ve been thinking that I’ll start getting together the parts for a clutch swap. With over 80+k miles on the clock I’m expecting the clutch to need replacing in the not too distant future. I’m also convinced that this car has been tracked at some point by previous owners again increasing the likelihood of increased wear. The car itself is not showing signs as yet. Its going well an is eager to go faster when the load button is pressed.

    I’m thinking I’ll be going for the Bofi Stage 2+ kit on the premise that it will cope well with heavy track use and a lightened flywheel to make it a little more eager.

    The other possible development direction might be Aero with a splitter at the front, some underbody air flow smoothing and wing at the back and probably done in that order. But that’s a cerebral exercise for now as the car is going well and I’m probably still less competent in my driving than the car’s capability.

    Finally there could well be the option of doubling down on my BBR GTI upgrades and going for the Cam upgrade to take the car to 200 BHP.

    I’m back at Thruxton next month so if you see me come over and say hello.

  • Set the controls for the heart of Thruxton

    Introduction

    So this week I’ll be popping over to Thruxton Circuit for some fun in the sun. I’ve done the driver briefing and filled in the wavers so I’m good to go.

    Car Preparation

    As usual the weather guru’s have been consulted and predict hot and sunny with 20c to 29c during the core day. So it looks like it’ll be a top down kind of day.

    The Yokohama’s (AD08’s) will be the tyres of choice resplendent on their black rims.

    Tyre pressures have been checked (1.9 Bar), wheels torqued up to spec (100Nm) oil level has been is checked, ditto the coolant level. It’ll all get checked again when I get there.

    Super Unleaded will go into the tank and extra in the can on the morning of departure and I’ll get sandwiches, pop & crisps for the day at the same time.

    A tool box, work mat, fuel can, a picnic chair, tow-bar, tyre inflator, pressure gauge, a puncture kit and umbrella (as a mini sunshade) will go in the boot.

    Sandwiches, pop and crisps; helmet, HANS and anything else will go in the passenger seat or footwell. I’m on my own for this one, no support car for me.

    I’ve charged up the batteries on the GoPro so I can have a go at recording some video this time.

    I’ve noticed the air-con might be a bit feeble so the journey back might be a trifle warm, we’ll see.

    Mods since last time

    On this occasion I’ve added some chasis bracing to the frame so it will be interesting to see what effect this will have on handling. I’ll write it up next week.

    I’m not sure that the new rain light will have much effect on a sunny day though it also adds an extra brake light repeater function which may help those overtaking me, know wha I’m up to!

    As above I’ll be running on the Yokohama’s rather than the Dunlop’s.

    Can’t wait…

  • New Bracing Goes In

    New Bracing Goes In

    In this post

    My MX5 NC already has some chassis bracing both on the front struts (see the images in my previous posts)and on the chasis rails underneath the car (see below), in this post new upgraded bracing goes it to try an improve already excellent handling.

    The why of it

    From the start the aim has been to create a grand touring track day car and in my post on the new BC Racing Coilovers, I mentioned that the car had acquired a kick when changing gear under load and whilst this was not a track day problem it was a put off when driving on the street.

    The forums suggest that this can be chasis kick caused by the relative softness of the previous suspension no longer soaking up the chasis twist from the rotation of driveline.

    It may also be a contributing factor that I Polybushed the rear suspension and the diff bushes where replaced with even harder poly bushes.

    Sites like Flying Miata suggest that it is difficult to overdo chasis rigidity and forums have suggested improved feel in the driving experience.

    For all these reasons and because they are hidden underneath the car I pushed the go button the IL Motorsport X-Brace and Rear Suspension Lower Brace as a first step in bolstering chassis rigidity.

    Why IL Motorsport?

    Only because I liked the look of the parts (they’re red) and in comparison to others they seemed pretty good value. I didn’t buy the full kit because I’d heard that the OEM front suspension tower brace is pretty good anyway and doesn’t really need replacing and the OE front bar (before the X brace) could be upgraded later as it is still pretty substantial.

    Instalation

    So you need to have confidence that the suspension won’t collapse when you start loosening bolts, and you’ll need to take a moment to search google for the installation instructions which didn’t arrive in the box and then a further moment to get your head around the instructions before you start any of this.

    I lacked the confidence to pull the bolts without chocking the subframe but it was either overkill or additional body stabilisation for the whole operation.

    I found that you need to pull the bolts out first, then instal from the back forward as the suspension brace sits under the cross brace. The hex bolts supplied replace the originals from the cross brace (I wasted 10 mins trying to work out why the wouldn’t bite on the suspension bars).

    The instructions also give torque settings for all the bolts, but these are pretty low. I triple checked them all with a torque wrench.

    Impressions

    They are both light and strong, the OEM x-brace could be flexed with my hands but the new one could not. Once I worked out what went where and how, it all went on pretty easily.

    As the rear module sits on top of the existing subframe rails it does hang down below the chassis and lower suspension arms rails a little (~1 – 1.5cm), the X brace less so as it is a replacement for the original. So if you have clearance issues you’ll need to work around these when driving over an obstacle or like me when pulling off the drive.

    It does not seem to foul the BBR exhaust that I can see, but it gets a thorough shake-down test next week at Thruxton.

    How the mod affects handling is something I’ll find out next week when I’m back on track.

  • Rain-Ready Now

    Rain-Ready Now

    After the biblically wet track days at Silverstone and Thruxton recently, I decided to take the hint and get a rain light. Of course it’s not as simple as, “Lets buy a rain light”, you then need to navigate the options.

    Choice 1: I decided that I wanted an FIA approved one so that it was of a modern standard and not just something cheap which may or may be of use. So I bought something that was compliant with the FIA’s 2019 reg’s (yes I know I’m not competing – but being compliant with current race regs reassures me it will be track relevant).

    Choice 2: Round or Rectangular? I opted for rectangular merely as I liked the link of it more.

    Choice 3: Flashing or Constant? I read that flashing rain lights are easier to see than constantly illuminated ones when you are following from behind. In my Silverstone Post I talk about cars passing and nothing being visible behind the cars but grey water; so anything to improve my on-track safety drove me towards a flashing rain light.

    Choice 4: Flashing, Flashing and Brake Light or choice of Flashing with constant via switch; I chose to wire it as brake Light repeater with a switch operated flashing function. Obviously I don’t need to be completion class rules compliant which would have limited my options .

    ÂŁ150+ later I was the proud owner of the CarTek 8874-2019 Rectangular Model Rain Light.

    FIA Flashing Rain Light from CarTek

    Instalation

    The three wires were expended with soldered wires and heat shrink and then I extended the heat shrink to to a length that takes the protection well under the car.

    As I was rooting around in the boot I noticed a large rubber grommet which gave me an entry point for the wires. Once the wires were brought up into the boot I found an earth point near the rear lights and then tapped the red wire into the brake light loom. The final blue wire which is the feed for the flashing function was fed through behind the seats and into the cabin under the centre console and the onto the designated switch.

    I’ve removed the panel below the radio which usually houses the lighter, aux audio input point and heated seat switches a while ago and eBayed the same panel from a lower spec NC and installed the illuminated switches for this unit and the intercom.

    As the switch is illuminated I ran a power feed off an auxiliary fuse box to the switch and ran an earth to an earthing point under the centre console.

    So there it is, I now have an additional brake light repeater and when required I can run a flashing rain light on track days.

    Another option would have been to rig the rain light so that the flashing function requires the headlights and rear lights to be on. I’ll think about it but and the implications for the future.

    First Impressions

    It was easy to instal, it’s bright and it works. I like it.

    Ironically there’s a yellow warning for heat out at the moment and no rain forecast for some time. Probably just in time for when I return to Thruxton next month.

  • Wet One at Silverstone Track Day

    Wet One at Silverstone Track Day

    Last June (2025), Silverstone was hot and sunny, we took a support car loaded with tools, tyres, gazebo and picnic table; and iit was glorious.

    This year the June track day was cold, breezy and rainy, though to be fair it settled down after 14.00 and the sun made an appearance, but what ever the weather a track day at Silverstone is such fun.

    It’s an expensive venue so it’s a once a year treat for me. This year the weather forecast was bad enough for me to cancel the support car because sitting in a car for much of the day gazing at the rain and being bored while I was out on track having fun was not something I wanted to inflict on anyone.

    Tyre Choice

    My Yokohama AD08’s were swapped for my SportMax road tyres in the rain the day before as they’d be no use in the expected heavy thundery rain.

    An early morning start on the motorway saw mixed conditions and I stopped at the services on the A43 at Brackley and took the opportunity to top up the petrol can with Super Unleaded and then a short final leg to the track and registration at the old pit lane.

    Setting Up

    The rest of the pit area
    My Pit

    I arrived at the track at about 7.30 and the gate and parked near the Cafe. I registered and got all the info want back to my car and pulled all the gear I’d crammed into it out.

    Two tool boxes, torque wrench, and a dry box for my food and drinks. I pulled my tow bar out of the boot and packed by helmet and HANS bags into the waterproof box.

    I placed the gear in front of the car so my Pit Box was clear to anyone who might be tempted to block it when I’m out on track. This has happened to me before at Castle Combe and is particularly irritating especially when your gear is in full view of them. I now reverse park and go no further back than the line for this reason.

    The Paddock
    The Padock, Drive up to the big truck and turn left into the pit lane.

    Some cars pulled in beside me and they arranged their cars specifically for this reason, telling me they have had similar experiences.

    Car Prepration

    Having experienced a bit of torque twitchiness on the motorway I backed the rebound on the suspension to +5 (five clicks from softest) with a plan to adjust as I went along and then also reduced tyre pressures to 1.8 bar (cold-ish)all round ready for the rain.

    suspension adjustment made easy with extenders all round
    Dial to max soft then +5 clicks

    Once round all the wheel nuts with a torque to check they were all firmly at 100nm and I was ready for the briefing and sighting laps.

    Briefing

    The Briefing was well attended with an explanation of the format of the day, the flags in use, when we stop for lunch, rules for overtaking, then it was back to the car to kill time until the sighting laps.

    Game On

    A wet track

    The sighting laps started at the usual pace and speeded up. After that the track opens and we’re on our own.

    Silverstone in the rain paddock side is bleak, track side however is much more entertaining.

    I followed the usual pattern of trying to get some heat into the brakes and tyres and building up speed as the laps tick by. I managed to get between 80 and 90 mph down the Hamilton straight, 90 to 106 down Hanger and 80 to 100 depending on the intensity of the rain and whether I was giving way to faster cars or not. Never once did the car feel like it was aquaplaning on the straights or braking in straight lines.

    Turning however was another matter several times I underbaked and the Traction control pulled it all back together.Appart from the trying the tarmac run-off between ?? Maggotts and Becketts, and going all wheels over the line at The Loop which is very slow and for which the car was off line due to the traction control being unhappy that I was pushing the cornering forces much harder.

    Given the weather I elected to put in more laps each time I was out (uptown blocks of 10 laps) and this help build a better picture of the conditions and the available grip.

    There were some really nice episodes where I had an open track to play with. On others I was forced to pull over on the right side of the track to let faster cars past. In the rain this can create a worry effect where there is vision at the sides of the track but a grey hole in your vision where you know the cars should be but you can see nothing but grey water as they speed past you (especially at the end of the Hanger straight).

    After the lunch break things began to dry out and I was able to get the roof down on occasion.

    Thoughts on the Day

    Despite the weather I found nothing to put me off Silverstone in the rain though I prefer the dry conditions for grip.

    I used the petrol pumps at the circuit rather than drive to Brackley on this occasion as I was shocked to find at the lunch break to find I had been racking up the laps and was down to less than a quarter of a tank. MPG for the car had dropped from 37 to 22 with enthusiastic driving on the track and across he whole day (including travelling to and from the circuit) I used nearly two tanks of Super Unleaded.

    In the wet conditions the tyres remained pretty intact with none of the heavy wear and melted rubber from the previous year evident.

    The brakes (EBC Yellow Stuff on normal discs) were again superb.

    The new suspension was excellent and I ended up settling at +7 clicks.

    Given the rain and some visibility issues Ive decided to buy a flashing rain light as a safety measure for similar conditions.

    Hopefully I’ll be back next year.

  • Heads-up: BC Racing DS Shocks

    Decision made, have ordered some BC Racing DS Coilovers.

    Deep joy.

    TBC

  • Foggy Headlights – Cured

    Foggy Headlights – Cured

    I love it when the plan comes together, I’ve been meaning to sort out the foggy headlamps on the car caused by the plastic being aged by UV over time and have been watching YouTube videos about re-polishing headlights that are going cloudy; something you see on MX-5’s a lot.

    Usually they show a wet sanding method moving up through the grades of paper to the finer ones. In one video I watched the lad spoke about his dad just going straight for some T cut. In my head I combined this with another one in which the presenter pointed out you can buy headlamp polishing kits for this sort of thing.

    This got me thinking about what if I bought a rotary polishing sheepskin wheel for my drill and used the T-cut I already had for polishing would this work?? Well yes it does.

    So my method was to apply the polish to the sheepskin wheel and then went at it with the slower speed setting with the drill. I followed the shape of the lamp, concentrating on the milkiest areas and also did some rotary patterns to mix he polishing actions up.

    I reloaded the pad with polish after one song on Planet Rock with associated DJ chat and then repeated the process for a similar amount of time.

    To be honest as the T-Cut starts to dry while you are polishing you can see if you are making progress.

    1) Foggy Headlight – not yet an MoT fail.
    2) T-Cut to Polish Light
    3) Drill with polishing wheel and sheepskin
    4) Result after two five minute sessions

    Now follow-up is more tricky as you need to coat the lens with something to protect it from UV going forward and I have some headlamp film to do that which I’ll fit next time. I

    I’m very happy with the result.

  • Broken Key – Sorted

    Broken Key – Sorted

    One of my car keys got broken beyond repair when the transponder chip got damaged as well as the casing.

    Researching the solution I found I would be fine if I had two working keys but sadly I only had one.

    Worse, Google’s AI told me it thought the cost for replacement would be painful. I put it of for a week or two but solid track day bookings meant I’d need to get it sorted out in the short time I had left.

    I phoned a local auto locksmith (Doms Locks) explained the predicament and he told me that I could be up and running with a non-branded three button key, cut to match my MX5 key profile and with a transponder chip programmed for my Mazda for ÂŁ160…. SOLD I said.

    So he drove over in his van, cut a new key and programmed the transponder and the other key functions. I have to say I’m really happy with it and I now have two perfect keys once again and I got to talk about cars with another petrolhead for an hour.

    The key’s buttons have open, lock and boot opening functions but not the alarm isolation button that I’ve never used anyway. It is not a match for the OEM as you can see from the photos but it all works and the car is unlikely to be worth very much anyway should I ever sell it.

    So if you are in the Berkshire/Surrey area and need a key replacing, he might be worth a call.

    Next week the car is off to Aylesbury have its steering wheel modded and reupholstered in leather – more of which soon.

    It even comes with a Mazda badge
    Replacement non-manufacturer replacement key with Mazda badging.
  • New Towing Eye

    New Towing Eye

    I’ve always been concerned that the OEM towing eye was a hazard for pedestrians when I was not on track and also that removing it left access for water and created a rust trap – as with the rear one that I had to replace as it was corroded badly.

    So I decided to replace it with this one from Jass Performance. It screws straight in and looks better than the old one. ÂŁ38 well spent.

    Im booked in now for Silverstone GP Circuit and Thruxton, so on with prepping the car.

    Dilema

    I’ve managed to break on of my keys when it literally fell apart on me and I’ve no transponder for a replacement.

    The question is whether to risk it or get another key. Apparently I need two working keys to programme a third.

    TBC

  • Nice new windscreen fitted, next the MoT

    So it’s been raining (again) and is therefore the perfect day for Autoglass to come and change the windscreen. I’d noticed a crack in the screen when I was fixing the water leak and it seemed long enough to cause concern about my upcoming MoT so it needed sorting out.

    The process was painless enough, book it in for a date, confirm and find its a different date to the one you wanted so change it and get something more convenient.

    They ping you by text to say they’ll be there sometime on the day you want then nearer the time they give you updates to say they are on their way.

    The lad who fitted it was friendly and got on with it under the really impressive awning/cover mounted on the roof of their van.

    Anyway it’s done, the screen looks beautiful and much cleaner than the old one. The instructions were something like don’t drive it for half an hour, don’t wash it for 24 hours, don’t worry about the rain that’s ok.

    Next up I’m going to book the MoT and then cross my fingers in the hope that I can then get the season underway and get it filthy again.

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