Monday, 30 March 2026

Badges and clutch stop

 The first task from this weekend was a clutch stop to prevent the pedal from moving too far. The problem is I didn't appreciate how much travel I'd put into the clutch pedal! It's not surprising that the clutch pedal can push it too far. But it meant that to add a physical stop would have had the bolt mounted either on the cylinder itself or where a brake line lives. Although looking at the pictures using the upper mounting bolt may be an option;


I may look at that during the week, it's only just occurred to me. I was looking at drilling a new hole and dismissed the idea.

In any case, what I did do was add a sleeve to the pushrod to limit the travel there. 

This works very effectively and is quite a hard stop on the pedal. However it's effectively pressing against the master cylinder and I'm wary whether that would be considered an issue at the retest.

This is the slave cylinder at rest;



And at full travel with the stop in place;


If I compare that to with it taken out;


It does really help with the movement but it's not strictly needed to get past the test. So it stays off for now.

I can actually see the upper fixing bolt of the MC in a different photo;


Access is tight but I could figure out a decent bolt length pretty easily. I'll keep that as option two.

Given that I have almost nothing to do on the car, I thought I'd look at a bit of decoration. On with the 3D printer;


It was a bit of a faff getting it from text to 3D lettering but I got there in the end. It looks nice on the car as well;


The size looks good and the lettering suits the car, the only issue is the colour. It needs to be metallic at least, if not chrome. I'll see if I can find some chrome (ish) paint and give it a spray. 

This will sit with the boot, dashcam, phone mount and all the other bits and pieces to be added post-IVA.

Lastly, I gave the corner weights a go. It wasn't particularly accurate but when I started I could see the left hand side was 30Kg lighter than the right. That would be enough to throw off braking efforts. A few tweaks to the spring platforms got it to about 5Kg difference. Although I then remeasured the indicator height and they're about 10mm different either side. It probably won't be noticeable but I daren't do any more tweaking with springs. A quick drive down the road showed that both wheels locked up at the same time which is pretty much perfect. I have also dropped the tyre PSI down to 18 so all of that is basically giving the car the best chance for braking efforts. If it doesn't pass with all that then it's major surgery time, either a different master cylinder (and therefore different plumbing) or even worse would be a brake booster which would need some major mechanical changes. 

On the subject of brake booster, I did speak to someone on LCB who used the MX5 brake booster. I was trying to figure out how that would be possible, but then after seeing a pic I realised what was happening;


His car uses a lot more of the pedal box from the MX5, including many parts that I discarded. This way round means the pedals come down from above, and all the mechanical parts work the same way as the MX5. Most importantly this keeps clearance for the brake booster. 

I can't really follow this approach as my fuse box lives where all this would go, but it does explain why he was able to retain the brake booster. 

Still, just driving my car a short distance shows the brakes are effective, so I'm still hopeful an unboosted version will suffice. I now know of at least one car that managed to get on the road without the booster;


This is from another car on LCB which shows the same MC that I'm using. 

Just for reference (and I have a feeling I've already posted it somewhere), I currently have;

134Kg nearside front
194Kg offside front
91Kg nearside rear
96Kg offside rear

For a total braking effort of 515Kg. From a design weight of 770Kg that gives me an efficiency of 66.88%, which is a pass. The new design weight of 400Kg + 500KG (900Kg total) that would only be a 57% efficiency.

To pass I need to get it to 60% efficiency, which is 900Kg/60%, or 540Kg. In other words I need to gain 25Kg of braking force. That really isn't much to be honest, the new discs and pads have an improved surface area which should suffice. In theory because the front wheels locked then the brake effort there is more about traction than brake effort, but with a dry day and reduced tyre pressures I should get more out of them. At the very least both sides should be reasonably even.

Interestingly just looking at the braking efforts again the parking brake gave 272Kg on the rear, whereas the service brake was only 187Kg. That does suggest the mechanical leverage given by the master cylinder is less than the handbrake, given both act on the same brake pads. Again, if I can get a little more on the rear that will also help. 

I need to take my mind off the brakes though, I have done literally everything possible. All the other issues were well defined and have a nice big tick next to them. The only thing I really need to focus on is the drive back to Bristol. More specifically, the weather at the time of the drive! If it's dry then great, if it's sunny then even better. If it looks like rain I'm going to need to do some prep work. 

Oh yeah, and I cleaned the car! Only a quick wipe down with soapy water but it really made it look good. 


Wednesday, 25 March 2026

Dashcam and pedals

 Not exactly two subjects that go together, but I thought I'd get them done in one post. First is the camera;



It's not quite as 'discreet' as it was in my head, but then the camera itself is as large as the rollbar. It works well though, with plenty of coverage. I did try the lower bar but the video showed more dashboard than outside. Discreet, yes, effective, not a chance!

It needs a TPU end cap to seal the wiring (I might even go with some silicon to seal the end) and when it gets mounted on the roll bar it will need sealing and gluing in place. Despite the tolerances being quite good it does rotate around the roll bar so it'll need fixing. It's a bit 'belt and braces' for the camera anyway. 

The next thing is the clutch pedal. On the IVA I had trouble getting it into gear a few times, I put it down to a worn slave cylinder and engine heat. Pressing the pedal right down didn't work and I was worried the car would have to be left at the centre! 

Replacing the cylinder seemed to help, until the weekend when it just wasn't happy. With my foot to the floor it wouldn't change gear. But as I lifted my foot (still with my hand on the gearstick) it dropped smoothly into gear. It turns out that if I only apply half pressure to the clutch pedal the gears are really smooth. A quick check online shows that it is possible to 'over throw' a clutch. If you remember I didn't put a back stop on any pedal as I thought the master cylinders would take care of it. In the case of the clutch pedal that's actually wrong. So I need to add a back stop to the clutch pedal. The brake pedal doesn't need one as the force of the brakes provides the stop. And the accelerator works for the full range of motion so I can leave that one alone too. 

So this weekend I'm going to drill a hole through the bulkhead and add a bolt for the clutch pedal to hit. Alternatively I could add a nut to the push rod to reduce travel, although that would be harder to adjust (the bulkhead bolt could be adjusted from inside the engine bay).

The one thing that had occurred to me is that if I had figured this out earlier and added the back stop, I could have avoided moving the brake pipe as the clutch fork wouldn't have hit it. I guess as with all the other fixes it'll show Mr IVA that I won't just settle with 'good enough'. 

Thinking about it that's been the case for most of the fixes. The number plate 'might' have been ok with just rounded edges but instead I've replaced the whole thing to show a border to the examiner. The indicators 'might' have been ok just painted but I actually moved them AND painted them. The exhaust fixings have been replaced and I've used locktite. The change of design weights could affect braking efforts so I've replaced the discs and pads. The fuel pipes got moved and got new fixing clips. 

Of course, none of that is reducing my stress and anxiety levels for the retest. I'll be glad when it's passed.

One more job for the weekend, alongside the clutch stop, will be checking the battery charging. A very simple check to confirm the alternator is behaving. I know the battery is new and can hold a charge, and it's very capable of starting the car. It also ran fine for the duration of the test and I've not charged it since, but before the long journey I want to make sure it's got 14 volts when the engine is running. 

Oh, and I want to give it a clean. I didn't appreciate how dusty it would get in the garage, and the inside needs a wipe down as well. 

A quick note for possibly later on. The consensus for the brake issues is that a smaller master cylinder may be required. I won't do it yet as I still believe the standard MC should be sufficient (if a little hard work on the brake pedal). But in case it is, the standard MX5 is 15/16 inches (although brakes international say 22.2mm which is 7/8 in). The book uses a Sierra one which may be the better option, I just need to know which Sierra one.


(Later that day)


A quick extra bit here, not enough for it's own post but I do want to note it down. When I took my car for an IVA, I had an immediate issue. As I was loading the car on to the trailer, the car grounded out on the corner of the trailer. There were two reasons for this, first the natural 'spring' of the trailer was designed for heavier loads so the One couldn't actually push the trailer down to make it flat. The second is that the car was just too damn low! 

Ride height is something I'm going to need to work on as I drive it more (potholes and speed humps are not low-car friendly). Initially all I did was raise the car on the spring seats, just to get it high enough to load up. But a post on LocostBuilders reminded me that I had done this, and not particularly scientifically. 

The issue is that the spring seat height has a bit of influence over corner weights, which could explain why the passenger side front was about 50Kg lighter on brake forces. So another task for this weekend is to reset the suspension ride height. Obviously with the car already tested for self centering I have a bit more freedom to set it to 'driveable' positions. I still don't want it too low but having it equal on both sides will be a good start. I may even do the corner weights again, just to make sure they're the same across the front. Again, that's another step closer to having greater braking forces across the front. 

And I've just remembered something else... the grub screws on one of the collars rounded off. I need to fix it. Suddenly I've gone from not having much to do on the car to 'this is several weekend of work'! I've just checked in the garage and I have spare grub screws, so at the very least I can drill it out. It's the drivers side rear so could be really easy to sort, or just an absolute nightmare. A brief test suggests it's a bit secure. I'll also look at some protection for the spring seat threads, probably just silicon grease. 

Monday, 16 March 2026

Waiting

When I started this build I knew it was going to be a long term thing. I started it just at the wrong time in my life, with a kid on the way it wasn't going to get any significant progress for a fair few years. Just looking at these blog posts shows the difference between the beginning of the build and the end. The beginning was a post a month if I was lucky, now it's a post every weekend (with a few exceptions). 

The bit that I hadn't really appreciated was the waits for the other steps. I had expected a few weeks for the IVA appointment, that was a few months. I expected a few days for the retest, I still have another 3.5 weeks to go. Then there will be the registration stage, and again I get the impression that could be measured in months rather than weeks. 

It doesn't help that the delays result in a lack of progress, or at least what feels like a lack of progress. This weekend I didn't get anything done on the car, and I suspect the next few weekends will be similar. I ought to get it out for a warm up and a clean, but I daren't do much more. I do need to get the boot bolted up, that could be worked on. But that's for the kit car show at best, I can't have it in place for the test. 

I did get both tintops serviced and cleaned though, which they both needed. I also replaced the DSG thermostat on my Skoda, that's been struggling to get up to temperature almost since I bought it. At least now it gets nice and toasty very quickly, then the rest of the engine catches up later. Replacing the thermostat wasn't actually too bad, only a three on the 'skinned knuckles' scale. The main thing that helped there was a proper set of pliers for removing pipe clips, having ones that properly lock and also have a ratchet to keep the clip open was a godsend. And actually not that expensive on Amazon. I doubt they'd have helped on the kit car but they're perfect for VAG cars.

Oh, there is one thing I checked on the One. The radiator fan, I wanted to check it was working. Once I'd figured out that the radiator thermostat is on the front of the engine rather than the back, a quick short to earth was enough to trigger the fan. So that's one more job ticked off. 

I also have a dashcam ready to fit, or more specifically a dashcam ready for a 3D print design that will then be ready to fit. It's a small camera from Wolfang that hopefully won't stick out too much. It's front and rear as well, so as long as I can shorten the wire considerably I can put both into the roll bar mount. I will need to make it waterproof though, I'll add that to the design. Having it under the roll bar might help initially, then some sealant around the seam would finish the job maybe? It does need to be removable though, just in case the worst happens. Actually, perhaps a TPU outer shell might be effective. I'll have a think about that. First step will be to get the camera shapes into onshape then I can build the mounting around them. 

Well, I think that's it for today, the coffee has kicked in so it's time to start work. 

Wednesday, 11 March 2026

Boot part two

 Not much of an update, I'm trying not to do too much work on the car in case I make the IVA worse. But the boot lining is coming along;


I'm happy with how it's coming along, although the piece of aluminium on the back wasn't quite as high as it could have been. Not an issue though, I'll just reduce the side curves to meet at the correct height. The sides are just wood at the moment, once I've decided on how to fix them in place I'll cut them from aluminium. It turns out I don't have as much aluminium as I expected, I guess I was being quite efficient with the last sheet and the mudguards. I don't remember wasting any either. But I do have plenty of mild steel sheets which probably isn't good. They'd need cleaning and protecting, and they're a great deal heavier which isn't good. So I'm staying with the side panels as aluminium.

One thing I do need to consider is movement. I don't really want things rolling about in the boot so I want to use some partition or webbing to keep things still. I do still have a cargo net from an older car but I think it's too big. As an alternative I may just add tie down loops to the base that can be used as required. I doubt I'll ever be going far enough to actually need luggage, but I do want a small toolkit and some tyre inflator in one corner.

Given the side edges have to be even lower than they are now, that does remove any opportunity for finishing the trim up to the side of the boot. I don't feel like that's an issue, the boot would do it's job and in most cases would be unseen. I've certainly seen worse boots at the kit car show, including some that aren't even lined!

In other news I've printed my phone holder so that's waiting to be fixed in place after IVA. And I've also added a bit of glue to the number plate to make it a bit more rigid on the far edges. It should peel off quite cleanly after the IVA but if it helps get a pass then it's a small price to pay.

I've not yet found a dashcam, it's quite difficult to find a reasonably priced option that gives a decent image. It's not as if I'm looking for amazing night vision capability, after all I would hope I'm never driving at night or in bad weather. Obviously just in case it does need to be waterproof but size is probably the main factor so it can go on the roll bar without being a big blob.

I do need to get the car out and up to temperature, that's the one thing that I'm wary of. It's actually quite difficult to get the car hot enough for the fan to kick in, I guess that's a good thing. But I don't want to be sat in traffic and have it overheat.

As the next 'post IVA' job I want to look at a heel plate for the clutch. It doesn't need to be much, but it does need to be very strong as I'll be leaning against it for most of the driving. I'll have a think about that one. I also want to look at some way of restricting bonnet opening, the normal way is to use a bonnet tie but the ones I've seen don't make much sense on my car. Talking of bonnet, I do want to fit some securing pins but I can't do anything with that until after IVA. Anything sticking out of the bonnet is going to be frowned upon, and it's not worth the hassle for now. 

Monday, 2 March 2026

Boot and other fixes

The weekend weather was quite decent so I managed to get quite a bit done. From Friday's post I had a few things I wanted to look at;

  • Tyre pressures. These are now down to 20psi on every corner. It felt really weird having them that 'soft', my last few tintops have been VAG cars and they favour very high pressures. Letting so much air out of them to get them down to 20 just felt wrong!
  • I've not done anything with the clutch, mainly because I couldn't get to the nuts! Having said that I did take the car for a drive down the road and it actually felt 'ok', mainly reverse was a struggle but that can be the case anyway (no synchromesh). 
  • I also topped up the tank, just to see what the IVA used. I reckon about a litre of fuel in total? 
I also fixed the telltale lights;

They look a lot less 'waterlogged' now which is good. The laminator option didn't work, it couldn't get tight enough around the edge to fit in the slot and still be watertight. however laminating the images with sellotape did work. It might not be long term but at least its better than just exposed paper. I also did the switch labels at the same time, same process.

I've designed a phone holder to sit on the transmission tunnel;

Nothing too clever, it'll just screw to the tunnel top and have the wire sticking up from underneath. That'll feed up to the battery and to an inline power supply of some kind. My phone is a bit 'old' so it just uses a standard USB power, no fast charging or anything like that. 

Now on to the main event, the boot. Given the size of the boot lid and the space available, I have a few options with regards to boot space. The first step was to simply 'fill in' the floor;


This alone showed up a few potential issues. First, the back bar on the bodywork isn't flat. It's not meant to be, the bodywork isn't flat so I had to make things match. But it does mean the aluminium floor also needs to curve. The dots in the picture are just small magnets, but they're also an indicator of where the screws will need to go.

The plan had been to make the floor 'angled', to fill in the triangles either side. But that is actually quite a bit of work, and overall I lose space. Yes it might look really cool, but it's simply not practical.

So in the end I just thought 'keep it simple' and went for side panels where the other bars are;


It means the bottom is filled out further and is not supported in the corner, but given that it was going to be folded aluminium I think it'll be rigid enough. There will be a back panel to hide the fuel tank, that will be a separate piece that is rivetted in place to make the box shape. The only thing I need to consider is the infill. There's a couple of options, the first would be simply to edge the aluminium with the edge trim. That would look quite tidy, it would be safe and do the job. Alternatively would be some profile to go between the boot side and the edge of the opening. That would be a bit more work, especially as I'd want this boot lining to be removable (so I can get to the fuel tank, wiring etc).

In terms of capacity, this design is;

  • 480mm high at the back
  • 180mm high at the front
  • 410mm deep
  • 810mm wide
That gives me a boot space of 109 litres. That's almost KLM hand-luggage levels of storage! It will be plenty for a tool roll, a jerry can of fuel and somewhere to put my helmet when I'm not in the car. I might even look at some anchoring points for straps. 

This boot is pretty self contained, once I have the template drawn up and cut it'll be just a few rivnut in the relevant locations. I'm still considering a better rivnut tool, they've proven quite useful and I'll be using them elsewhere but it's still a pain to fit them. Particularly the small M4 ones that I use for most of my fixings. I need to find some 'real' 12.9 bolts and nuts to stop things just turning to mush as I tighten them up. 





Friday, 27 February 2026

IVA retest booked

Now that all the work is done, it's time to get the retest booked. £90 later and I have the 10th of April, at the slightly more civilised time of 11am (although it's still an 8am start to get there in plenty of time!). It's also in the school holidays so hopefully less traffic. Well, at least on the way down, there is a possibility I get caught in holiday traffic on the way back. And of course because I can't see my phone very well it's not as if I can avoid traffic jams, I just have to take it as it comes. The main thing I'm a little disappointed with is the time until the retest, I thought it might be quicker. Initially they said next Wednesday which would be far better, but then they weren't able to book it. Nothing else showed up for all of March, so April it is. They did say I can phone back and see if there are any cancellations, so I'll phone up each Monday and see if I can get a cancellation. Apparently retests can be moved as often as reuqired. 

There are a few jobs outstanding, not IVA specific but more a 'quality of life' thing;

  • The first job is to drop the tyre pressures. I put them up to 30psi, partly because that's what the donor car uses but mainly because of self centring. The normal way to deal with a lack of self-centring is to put more air in the tyres, but that's all done now. It doesn't need to be 30psi, 18 to 20 is probably more suitable. This should also mean a bit more grip on the brake test rollers, so two birds and all that.
  • I also need to adjust the clutch. As I mentioned last time I've replaced the slave cylinder and it works well, but clutch disengagement still isn't the best. Fortunately I did retain adjustment in the pushrod, it's just a bit awkward to get into the footwell!! Once I get down there I'll get the clutch pedal tightened up so it can move the clutch fork as much as possible. Then maybe one more bleed before declaring it fit for use.
  • One thing for IVA is that I need a full tank again. Fortunately there is a filling station near to the test centre so I'll top up once I get down there, but in the meantime I need to stay with my jerry can to keep things topped up. There's still a bit left from the whole fuel tank fun and games so I'll put that in the car then go get another five litres (or two, depending on how much was used during the test). 

Given how much time I have, I'm also looking at replacement lenses for my telltales. On the way back with the rain all the symbols now look like they've melted. They still show the right symbol and colour but it's really not a good look for them. I want to redo them but make them waterproof. Luckily my wife has a laminator that will hopefully do the trick. I'll have to cut the symbols really closely to the edge to maximise the laminate seal, but if that works it'll be a longer term solution. I could do the same with the toggle switch legends but they're a lower priority. It could also be partly to do with the bulbs no longer being sealed, as I've mentioned before I had to go for a version 2 of the lights with a bit extra room and ventilation for cooling. Of course, whatever lets air out can also let water in so that's not a solution anymore.

I'm going to need somewhere to put my phone when I go for the retest, in my jacket seems logical but also having it visible would help. Hmm, I have a 'sticky' pad somewhere that is meant to keep things from sliding around on a dashboard, I wonder if that would work here. I will also need a battery pack as I have no USB source yet. Definitely one of the first things on my 'to do after IVA' list. 

Soon it'll be time to service the two tintops so that will be a nice distraction. But overall now I'm just waiting for the retest and trying to resist the old engineer adage 'if it ain't broke, it ain't got enough features'... 

Monday, 23 February 2026

IVA fixes: fuel line, number plate, indicators

 The easy one first, the number plate. Now the new mount is on the number plate sits in the right place and there are no sharp edges. It's ugly, but it's not sharp;


Fuel lines was also successful, as mentioned earlier the main battle was going to be drilling the holes and fitting the rivnuts. Once that was done I could prototype the straps with cardboard;


Then cut and drill the appropriate steel version. As it's steel rather than aluminium, they needed a coat of paint before applying, but I think they've gone on really well;



Because they're rivnuts rather than through bolts with nylocs I applied a drop of threadlock to them. I don't want the bolts falling off before I get back to the test centre!! Of course, threadlock plus rivnut is not a good idea at the best of times but with any luck these won't need removing at all. There is a good fingers worth of gap all round the pipe as it goes past the mount, it's also going through the largest gap possible which is next to the rubber. 

So that's two jobs ticked off and now the car can be put back on the ground. And guess what... the indicators are still too low!

The illuminated surface (which is what is measured) is a few mm lower than is required. I suspect Mr IVA would be fine with it, but to remove doubt I'm combining this approach with the original suggestion of masking off half the light. I currently have the lenses sat behind me, getting multiple coats of paint to block the lower half. I also 3D printed an internal shield again to cover half, but that leaked too much light. I'll still use it, in combination with the paint. Again, probably overkill but it removes doubt.

Oh, and I need to replace the screws with IVA friendly bolts. 

Last one, the new clutch cylinder went on, and with it depressed it clears the brake pipe;



It does feel a lot better than the old one too, the old one used to get 'stuck' every so often. Not enough to be a worry but enough to feel in the pedal. The only thing I want to look at is the pedal travel though, I'm still getting some issues with clutch disengagement. If I can adjust my clutch pedal slightly I'll see if I can get it to operate a bit further. Of course that will depend on whether I put any adjustment into the clutch lever!

The new brakes are on, I'm still waiting for Royal Snail to deliver the brake carrier bolts that I want to replace but hopefully that won't be too long. I did see an interesting way of adjusting the handbrake though.

Normally to adjust the handbrake you turn the caliper adjuster until it locks, then back it off a 'tad'. I say 'tad', because there doesn't seem to be a consistent value that it's turned. I got it somehow right the first time but far more luck than judgement.

The other way is to lift the handbrake a couple of clicks, then 'snug up' the adjuster. That way when you release the handbrake it ends up being in the right place on both sides. This approach appeals to me much more as it relies on fixed end points rather than a vague 'that will do'. I'm going to try that tonight. There are a couple of views on how many clicks though, one video suggests two and the other says six. I'll try two first, if that doesn't give me smooth running brakes then I'll try six.

So a quick recap, here is my failure sheet;


  1. Exhaust fixings. Done
  2. Rear number plate mount. Done
  3. Direction indicators. A couple more coats of paint and screws replaced.
  4. Design weights. Updated.
  5. Clutch fork. Done.
  6. Fuel pipe. Done. 
So once the indicators are done and the bolts arrive I'll get it booked in. And then a few weeks later will be a licence plate request with the DVLA! 

(Quick update)

The handbrake is now adjusted, it is so much easier to do it with the handbrake on and 'snugged up'. It's nice and even both sides and hopefully a bit of a run will be enough just to take the surface off the discs. 

The clutch cylinder is adjustable but I won't do that just yet. It needs a bit of yoga to get to the right place and it's been a busy day. The caliper bolts also arrived so they're fitted and torqued up, and the new sticker for the brake fluid is stuck on. 

I've also bought some heat set inserts for the lights. I can't figure out how to get nuts to the back of the light fitting, but the brass fittings that are used for mechanical prints will work very well here. Once they arrive tomorrow I'll fit the lenses now they're painted. The paint did work, there's no light coming out below halfway so it's definitely meeting the requirement. 

Friday, 20 February 2026

IVA fixes: fuel line, number plate

Well, I managed to get into the garage last night and get a few messy jobs done. First thing was the rivnuts for the fuel lines. I was able to drill and set the rivnuts. I've gone for three locations in the end, mainly to cover the 300mm distance requirement. They seem quite secure and I've put a coat of paint on them to finish them, that should be dry by the time I come to bolt on the fixings. I'm going to use some cardboard to make templates for the strips, then cut them out of aluminium. My only doubt now is that the pipes are a bit of a distance away from the chassis, so the clips might need a bit of reinforcement to make them actually do something (rather than just look decorative). Given the old clamps made use of printed braces I suspect I can do the same here. What I definitely need to do today is cut the aluminium strip, it'll be a noisy task and I wouldn't be able to do it in the morning. Then again, I'm also tempted to see if I have some better material as I've only got 1mm aluminium. I may have some steel sheet that is stronger and thinner. It still needs cutting into a strip today though. If I use steel I'll need to paint it, otherwise it'll rust through in no time. 

The number plate also got it's first trial fit. And of course it's slightly too small. It's the rounded edge on the inside, it means there's maybe 5mm less space than there needs to be. And the screw holes are way off target, I'm not sure how that happened. The two underneath the light are maybe 1mm too far apart, that doesn't make that much difference. The bottom ones are a good 10mm too high, so I'd have to make new holes to get them to fit. Again I'm not overly bothered at this stage, those holes will get covered by the plate. The rounded edges work well which was the main task here, and the extra brackets on the outside fitted well and coped with the rounded back end. They were also glued up and left overnight so I'll get those finished today. 

Just thinking about that rounded edge... I could sort that before I mount it, so not leave any doubt that a plate will fit. All I need to do is remove the two rounded ends and replace them with a different profile. I might go grab the plate shortly and see what to do.

With any luck this weekend will have the fuel lines finished and the number plate finished. Then I'll get the clutch cylinder replaced (two bolts and a bleed). Then it'll be trying to get some decent weather to get that last corner sorted for brakes. The Metoffice is saying the mornings look dry, but at least tomorrow morning I need to get to the key cutters for the new keys. I'm thinking early start, takeaway coffee, some form of cooked pig in bread... 

Thursday, 19 February 2026

Talking about the weather

I'm starting to get a bit frustrated from the last few days, and the weather is the main cause. There's just so much rain and apparently we've got another month of it yet. I know part of it is my decision to go for an open top car, but surely a selection of dry days in quick succession isn't too much to ask for?

I should be grateful that I have a dry garage to work in, although in some cases I still have to work with my a** hanging out of the door. Despite the garage making best use of the available space (it's wider than a standard 1 car garage) the car still takes all the space. And it's not a big car, side by side with my wife's Mazda 2 it's pretty close.

I have been able to glue up the number plate so that's ready for final finishing. That job definitely needs the garage door open so is a perfect example of a 'weather permitting' job. Same with the one remaining brake disc, I need to reverse the car out (or even turn it round entirely) to get that one done. But of course the car is in the air for the fuel line fix which is the main reason it's there.

In theory the hardest job for the fuel line fix is drilling the mounting holes. Once that's done it's a case of fitting the rivnuts, then the actual clamp can be made away from the car and just bolted in place when it's finished. I think I do just need to JFDI, probably at lunchtime today I'll get under the car and drill the holes. 

Of course that brings me on to driving the car. Apparently for summer driving the Roadster design means that a fair bit of engine heat gets into the cabin, while I've not experienced that it does give me a little hope. But I also wonder whether a bit of assistance might be good. The MX5 engine comes equipped with water inlet and outlet for cabin heating, they're actually bypassed at the moment but they could be restored. Then I could reroute them into something like this;

https://www.aliexpress.com/item/1005007660122030.html. 


Given that I have plenty of interior space available I reckon I could find a home for this. I'm a little confused why it has three outlets but four pipes, but hey I'm not complaining. I'll maybe save that for next season though, I'll see how cold it actually gets when driving and make a call after that. 

I think first 'post IVA' mod will be a wind deflector, just driving it round the IVA car park shows how breezy it can get. I'm not even up to decent speeds and I'm struggling. Of course, I know exactly what I want;


I just need to find one! Or more specifically I want to figure out how to build one, because they're really not cheap. The glass itself is £50, I'm not going to be able to do anything about that. The rest of the frame should be buildable though. Well, I think it would be. Ideally it would be made out of aluminium, but I don't have the ability to weld aluminium. And that's ignoring all the extra hardware that would need to be made. The other option is to keep an eye out at autojumbles for options, although I've been to a couple now and not seen anything remotely comparable. 

Monday, 16 February 2026

IVA fixes part three

Nothing huge to update as I was ill this weekend, I only managed an hour or so in the garage before I went back to bed. 

The new brake discs and pads have arrived, and I've fitted them to three out of four corners. They look a lot better and I suspect braking efforts will now be much higher. It has uncovered one issue though, the caliper carrier bolts are way past their lifetime. I was trying to torque them up and I could tell they weren't happy. Fortunately MX5parts sells replacements so I have four of them arriving this week. A quick swap and I'll feel a lot better with them. I was tempted to just find some M10 fine 10.9 bolts and be done with it, but given they were roughly the same price I might as well go for genuine. 

And now the first fail of the retest, the number plate. Despite it being the correct size, it is hilariously oversized on the car!


This is not the 'small' plate that many cars wear, this is a lorry plate! I couldn't even put the car on the floor with this one as it would probably drag on the floor! So that's going in the bin, it's completely unfit for purpose even if it is the right size.

The final option is a 'normal' plate. I discounted this early on because it's quite wide and won't fit between the lights;


But actually it's only 20mm too wide. So what I've done is move the reverse and fog light out a bit so a plate can fit in between;

The only thing I had to be careful of was the distance from the fog light to the stop light, that has to be 100mm. I'm guessing that's why I put the lights where they were originally as it was 113mm between them. Recovering 20mm for the number plate (10mm either side) means it's now 103mm between the two. In theory I could have the indicators inboard and the stop lights outside, but I don't think that's necessary.

One Onshape session later and I have a backboard for the plate and light;


Which is currently gluing and will be fitted into the correct orifice. That'll be this particular job concluded hopefully. I really didn't expect to have so much trouble with this one. It just goes to show how things can catch you out. The average sevenesque car doesn't have to deal with any of this, they have a nice flat rear end to house it. It just needs an appropriate light and that's it. 

With any luck I'll feel a bit more human by next weekend, and I'll get the fuel pipe clips sorted. Then I'll get the retest booked (after one more final checkover and test drive!). 


Wednesday, 11 February 2026

IVA fixes part two

Even though I feel like I've not spent much time in the garage, I really feel like I've made progress since last week. So here's a bit of an update.

Design weights.

While the process of updating the weights was quite simple, it's left an unintended consequence. The design weights are used to define whether the brake efficiency is correct. For my test it was 66.88%, and given the limit is 60% I'm not overly impressed. I expected the brakes to be much better, even without the brake booster. 

Turns out I was right to be unimpressed. Because now I've updated my design weights, my brake efficiency is only 57%. Which isn't enough for a pass. I did think about updating them again but that seemed inappropriate (even if they would have let me do it). So the alternative is to have them retested. I've confirmed it with DVSA that a retest would be done which is one half of the battle. 

The other half is the brakes themselves. Why is the efficiency so low? Turns out it's a self inflicted issue, reusing brake parts. I thought I was clever to reuse the parts, as I avoid the issue where brand new parts have very little effect until they're bedded in. Problem is I didn't record what pads go with what discs, so I now have this;


Given how much braking was done for the test, these should have been shiny. More importantly they should have been shiny all across the surface. And braking 101 teaches us that the further away from the centre the more the braking force, and guess which part of the disc isn't being scrubbed by the pad?!!

Simple fix though, new pads and discs are on their way from Autodoc. Febi Bilstein parts, front and back for £131. That'll teach me not to be too clever. Since I'll be driving to the retest I'll just make sure to give them a bit of time to bed in. Even if it means a slight 'detour' to the test. 

I am hoping it means that more force can be applied to the pedal before the wheels lock. Given the nearside showed 134kg and offside was 194kg, even addressing that imbalance should be enough for the car to pass. I need another 25Kg of force to pass, with 60kg between the two sides locking up I am hopeful/confident that a retest will be very simple. 

Oh, I do need to drop the tyre pressures, they were quite high to pass the self centering but now that's done I can get them back down. Again that means more grip and higher braking effort. 18 psi seems to be a good place to start.

Brake pipe issue

On to defect two, brake pipe touching the brake lever. Here's the before photo, with the clutch lever depressed;


This is quite a clear fail that I should have spotted, but as a lone builder it's difficult to predict. It goes to show that having 'someone else' take a look at things can help, ideally a fellow builder but anyone with an interest in cars will help.

In any case, it's just a simple reroute, I had to release the clamps to do it but now everything is clear.



This does highlight an extra job though, That boot on the slave cylinder has seen better days. New ones are £13 so I'll add that to the 'post-IVA' jobs. That might explain why the clutch pedal fades over time. Just looking on MX5 parts I can see a rebuild kit for £22 that contains a cylinder and boot, but since a new one is cheaper it makes very little sense not to simply replace it. 

Exhaust bolts

This was simple to fix, a nice sprinkling of nuts and clamps to resolve. 




The bottom one was interesting, the original nut was a nyloc but it didn't engage fully. I've replaced it with a standard nut and threadlock, hopefully that will improve things. It's not as if the clamp is going anywhere if the nut comes off.

Indicators

I wanted a solution that didn't need bodywork modification, so a light pod made the most sense. The problem is the pod had to deal with the bulb bayonet fitting. Even though I bought a pair of low profile ones, they were still long enough to warrant an extension to the pod.

And of course, the side lights are next to them, so it occurred to me that the indicators would be blocking them from certain angles. Despite the bodywork permitting the original fitting to work, it had to be raised. 

So I now have this;



The lights were only 1 inch too low, I've raised them 1.5 inches so they should be good now. Of course, the car is in the air so I can't measure them just yet. If they're still too low I'll block out the bottom of them like the examiner suggested, I just didn't want to do that as the first choice. 

I've got one more job to do on the indicators, the fixings above are just self tapping screws and not radius compliant so I need to replace them with cap head bolts. Not an issue, I just didn't have them to hand when I did this job. 

Rear number plate

This is printed now, to the correct size;


It mounts the same as the existing one, but is rounded off and to the correct size. It needs a light sanding then screwed on, but the rear of the car is at the back of the garage, and needs me to open the garage door to the elements. The current weather isn't just good for ducks, it's getting pretty close to what Noah needed. So I'll leave this as is.

Fuel lines

Leaving the best til last... this is what I started with;


It's very clear why it failed. First job was to get the pipes off the clip, and several bashed knuckles later I got them off;


At this point it was clear that my plan of just moving the pipes over the clip wasn't going to work. It would have left the pipes at the same height and there's just not enough space. 

The first job then was to cut off that clip;


The pipe was then able to drop down to the rubber part of the mount where there is much more clearance. Using a piece of wood for a brace against the body, I was able to put a kink in the pipe;



This gives plenty of clearance around the chassis and the gearbox mount so I'm happy with the positioning. The problem is that without that pipe clip there's about a metre of unsupported pipe. Given the pipe can move enough for me to put a kink in it, I obviously need to reintroduce new supports. I don't have a 'central' support anymore so I need to add one before the mount and one after the mount. Neither are difficult, a hole and a rivnut gives me a method of securing, then a metal covered 3D printed bracket will provide the support. It's just really unpleasant to work underneath the car when it's on axle stands. 

All this means that after this weekend most things will be sorted. I will need to wait for the brake parts to arrive, then I can book the retest. As I'm waiting for brake parts I've also ordered the clutch slave and I'll replace that at the same time. 

I guess the last battle will be the weather. Apparently the wet weather will be with us for a bit longer (thanks Punxsutawney Phil!!) so I'll have to delay the retest until the weather is a little drier.