Wednesday, 28 January 2026

More fuel tank

Oh why did I say 'no garage'?!! I'm back with a smell of petrol in the boot, so lucky me I think I'm tracing another fault. The last few days has just been one long headache, both figuratively (trying to find the fault) and literally (because petrol is not a nice thing to breathe in).

So good news first, the tank is sealed. There is no sign of any issue from the seams, I've done umpteen pressure tests with soapy water and all manner of checks, but I can't find any leak. There was signs of spillage outside the tank that was showing up with the UV light, but after wiping them off there was nothing.

My attention then came to the filler pipe as that's the main thing that I'm worried about. It turns out I was right to worry, because a pressure test with soapy water round the end of the pipe showed bubbles. 

This leads me to two outcomes. First is that the weld to the tank isn't good enough and it's leaking there. Second is the pipe isn't sealing on the metal tube. I do need to do a better pressure test to differentiate between the two. I have been having trouble maintaining pressure as the fuel cap I have is only pressure fitted. It gets a bit difficult to use the pump, maintain the pressure and check what's going on. What I've done is 3D print a 'cap'; 


This will take the place of the upper filler neck and use a jubilee clip to seal inside the pipe. Then I can use the bike pump adaptor to apply pressure and more importantly maintain it while I check things.

I've also got some better clips on it's way. I wasn't convinced the jubilee clip was the right one, particularly for spiral pipe as it can't apply even pressure. I really should have paid attention to Car Builder Solutions when they had the proper clips alongside the pipe. Since CBS aren't particularly cheap or quick I've had to switch to Amazon Prime to get some proper clips;

The idea behind these is that it can work with the spiral binding of the pipe and apply an even pressure to clamp in place. They should be arriving today and maybe if I'm really lucky they will solve the issue.

On the other hand, if it is the weld on the filler neck I have bought some fuel tank repair putty that will be applied to sort any hole in the weld. Ideally I'd reweld it but I haven't got time to drain and wash out the tank, weld up, repaint and refit it, etc. 

So I am nearly there, it's been a panic week to get it sorted but there is light at the end of the tunnel.

In other news, I had three holes through the bodywork at the back for the reverse light, fog light and number plate light. All needed grommets so they didn't chafe. The number plate light was the easiest to sort, I just used silicon to keep the wire fixed in place and not able to rub;


The other two needed grommets, and they weren't going to be easy to find off the shelf parts. So I decided to venture into TPU printing! For those not in the 3D printing world, TPU is a polyurethane filament that stays flexible after printing. It's not as soft as rubber, the shore rating is around 95 so it's pretty stuff compared to rubber. However it does provide a soft surface to act as a grommet.

Admittedly it took me four attempts to get a working grommet, it would appear that shrinkage after printing is a huge issue. Given the hole is 14mm across, I had to print 16mm wide to get a tight fit. But they're both done now so that's the last of the wiring. I've been over every section multiple times and cannot find any potential failure. 

One more job done, sort of. When the car is on the trailer overnight next week, there is a possibility it's going to be very wet so I need a cover. I don't think I'll use it when driving down to the test centre, but I do need it to stay put overnight. I bought a few metres of ripstop fabric, and printed some roll bar sized clamps to hold it to the car;



I suspect a bit of wind might fold over the edge and let water in but it's a decent start. At least the whole thing won't come off and land on the neighbours lawn! I just need to design and print a couple more clamps for the front, but I'm hoping this will be sturdy enough to survive the night. 

I am watching the met office website, since they only do 7 days ahead I don't quite know what the weather will be. I am still hoping for dry, I'd say warm would be nice but it's February so dry is about the best I can hope for. I'll first find out Friday what the weather could potentially be, but then it's still another seven days of changes that are possible. 



Saturday, 24 January 2026

Fuel tank, geometry, brake testing

 The fuel tank is back in, and I've topped it back up to full. No whiff of petrol at the moment, although I'll do a sniff test in the morning after any fumes have spent the night building up. This time I've also kept some petrol in the jerry can in case I have to do any more work in there.

I also lifted the front of the car a bit. I'm very wary that the sump is less than 100mm off the ground. Any speed bumps (like the ones all round the village!) and I'm losing my engine. The front lip was also lower than 100mm, or at least it was. I've lifted the front so it will get over speed bumps, but the engine is still too low. I don't want to lift it too high because it'll upset the handling and geometry. So for the time being it's too low to get past speed humps.

The plan had also been to sort out the front camber as it wasn't quite right. But lifting the front actually made it a lot more even so I didn't have to tweak the camber in the end. The rear looks a bit cockeyed but I can sort that another time. A quick wheel alignment later gave me 1 degree negative camber and zero toe. What it did also give me was 'some evidence of self centring'...

Basically what I was doing was taking it up and down the road to get some heat into the brakes and see how they behave. On one of the turns I accelerated and saw the wheel turn back towards straight. Which means I'm finally in a position to have that 'evidence'. Lets hope it resurfaces on the test!

What else is there? Oh yeah, the brakes work well and consistently, although still feel a bit squishier than servo assisted brakes. However, I did get a front wheel to lock up which is mostly good. Of course it could have just been on gravel but it's better the front locked up compared to the rear. So again, that points to things behaving themselves. I didn't get the brakes hot, although they were the same temperature both sides so that again is a good sign. 

A small digression, I did check the gearbox rear mount and it's secure so that's all sorted. 

One last job for today was the front trim. It didn't seem as secure as it was before, that carpet tape seemed enough but not a long term choice. That's now been reattached using proper silicon so it won't come off. 

Overall a very positive day. Everything points towards a pass which would be fantastic, but on the other hand a fail is so much more likely. As long as it doesn't catastrophically fail I'd be ok with driving it for the retest. Although at that point it would definitely have to pass otherwise I couldn't get home!

No garage tomorrow, or at least no time on the car. I might get in the garage and do some tidying, but given the car is basically 100% at this point I don't want to jinx it. Next weekend I'll charge the battery and maybe run it up to temperature for one last time before the test. 

I did wonder about this blog and whether it would continue. Of course it will continue, isn't that the whole point of a kit car? Planning ahead the first task will be getting the car registered and driven for a decent distance. Then it'll be prep for the kit car show, the first time I go as an owner rather than a spectator. I wonder if I can get a boot liner sorted before the show so it becomes a functional storage area.

After that, who knows? Perhaps a move to a 6 cylinder something? A paintjob? Perhaps a rethink of an aluminium interior once I've burned myself on it when it gets sunny?

Oh, I do need a phone holder that is good for navigation. Getting to the Malvern showground is pretty simple, I used to work very close to it so I remember it quite distinctly. Problem is that's on the motorway, and this car is not a motorway car. I'd prefer to do the country route but I need navigation.


Friday, 23 January 2026

Fuel tank checks, interior padding

 As I've mentioned before, I had a fuel tank issue and traced it to the earth connection. This is what tracing a leak with flourescent fuel looks like;


Doesn't it look pretty?  As mentioned I removed the bolt, cleaned it up and just smothered it with Sikaflex to seal it;


I'm still a little frustrated that I didn't remember the earth lead when I was welding it up, then I could have added a proper tab. Actually, even when I repositioned the filler I could have added an earth tab! Ah well, 20:20 hindsight and all that. 

It's fixed the issue though, I can open the boot, stick my head in and smell nothing but fibreglass and tyre rubber. And Sikaflex.

Back to the interior and I've added a couple of pads to the required areas. One for the shin-basher;


And another for the steering support;


They're not my finest work but they will do the job. It turns out that velcro wasn't just a good idea, it was essential. Those pads need to be removable in order to remove the front panel and get to the gearbox. 

As ever I've got a few more jobs to do this weekend;

  • Retest and refit the fuel tank. I want to do one more pressure test but given there's no smell I'm not expecting anything. Oh, and I've bought some longer bolts for the straps, as I noticed the old ones didn't go through the nylocs far enough. That would have been a daft mistake.
  • Check the rear gearbox mount. I'm sure I've checked it before but I just want to reach under and check it's got nuts top and bottom. Again it would be a silly mistake to have one missing and I'm 99% sure I've checked it multiple times already. But two seconds with a screwdriver (or even a jack to go underneath) will be enough to check it.
  • The wiring issue behind the dashboard turned out not to be an issue, basically when I tightened the sleeve around the cables I accidentally dislodged the ignition switch plug. Once it was plugged back in it was fine. 
I need to start gathering paperwork as well. I've found the V5 from the donor vehicle so that's coming with me. There's the IVA4 declaration, which itself talks about photocopies of detailed receipts for the major parts. Given most of the major parts came from the donor I'm hoping that eBay receipt will be sufficient. The one thing that was a 'cash' deal was the steering rack, no receipt for that one. 

I also have receipts for the steel and the body itself, so apart from the seat fabric, consumables and 3D printer filament I think I have everything covered. And yes, given how much 3D printing went into this car I am tempted to describe it as a major part!!

Actually, while I look at this the one thing I'm missing is the nuts and bolts, I have receipts for those. It talks about 'original receipts may be requested' but given most of these are electronic anyway I suspect the intent is a little out of date. 

Carrying on with the IVA4 doc, it talks about photographs depicting the various stages of build. Now I was aware of this when I started building, and that's partly/mostly why I started this blog. What I sent to the IVA people was a 'build diary', showing photos from each stage. I'll print that out and take it with me. 

Less than a fortnight to go.


Monday, 19 January 2026

Last of the interior fittings

After going over the interior a stupid number of times, the last IVA question was around the visible chassis members TR9 and SW3;


They are exposed and while they will 'probably' meet the radius requirements I didn't want to go into the IVA with a 'probably'. 

After asking the question I wasn't seeing many responses. But it turns out the gov.uk website had some extra info. On their guidance notes page https://www.gov.uk/government/publications/individual-vehicle-approval-iva-for-cars-help-to-get-a-pass/individual-vehicle-approval-iva-for-cars-help-to-get-a-pass#interiorfittings, they have a picture of what is included in the test.


The problem is that this diagram and what is in the IVA don't agree. 

This shows items below the instrument panel and above the 150mm line are tested by the bigger sphere. The guidance notes assume that the instrument panel is long enough to reach the 150mm plane, but in my car it doesn't. 

So I'm back to doubting whether it's acceptable, and to remove doubt I'm going to add some padded surfaces. Looks like another trip to the Hole in the Wall in Walsall! 

What I think I will go for is some strips of aluminium with a suitable gap in the middle so they fold. On that I will glue some light foam then black faux leather on top. Then I'll have a soft edge one side, and hard aluminium to fix it in place. I think silicon again to bond it in place, it worked well elsewhere. I need to work quick though, not many days left. 


Sunday, 18 January 2026

green fuel

Yesterday I filled the tank up to the brim and looked to check. What I found was green fuel, and while I thought it was odd, I just assumed it was modern fuel with all it's additives.

I was actually completely wrong! A while back I added some luminous dye to check for leaks, and of course now I can see the tank full I can see the dye! And yes, it glows quite nicely under UV light.

That took me back to my original plan to look for leaks. I still have a petrol smell coming from somewhere and cannot find it anywhere. However now I know the dye has mixed properly I had another scan for anything glowing. Of course, there isn't anything that I can see so far. 

I did dismantle the pipe connection behind the seats as there appeared to be 'something' there. But given the pipes took a lot of effort to break loose, and there was no glowing going on, I just cleaned the pipe up and reassembled it. 

So I'm 99.9% sure the leak isn't from the joints or the pipes, which brings me back to the tank. A small job for today (once I've typed this up) is to unstrap the tank and lift it off the cradle. Fingers crossed I find something but I really am not sure.

Oh, something else I noticed. The black paint I've used for the chassis and on the tank is not petrol-resistant. I spilt some on the cross bar and it went very soft. This is actually a positive for me, because now I'm not just looking for the dye leaking somewhere. I can look for soft paint. 

I really don't want to be presenting a car for IVA that smells of petrol, then again it's going to have been exposed to the open air for quite a while before the test starts. If I found a leak I'd actually be happy because I could sort it, not knowing where the smell is coming from is driving me up the wall. It's definitely from the back though, when you open the boot you can smell it. It's not the same when you open the bonnet. 

Oh, and one other job I'm considering for today is a pattern for the boot lining. It should be relatively simple, and I still have a decent sheet of aluminium left (I think). A couple of folds and a whole load of rivnuts will get something in there. It won't go in for IVA but I might be able to set it up for the car show. 

2 weeks and several days to go...

(later that day...) so a bike pump, a fuel cap seal and the aforementioned dye shows that there was a leak. It was at the earth point, it hadn't sealed sufficiently. Since the whole point of the earth point is to connect metal to metal, it won't be possible to use rubber washers. A copper washer might have been enough but I couldn't tighten the bolt that much without stripping the thread. So I've put sikaflex all over the rest of it, and then sealed the top. Once it's cured I'll retest it. Thankfully because it's a flat panel tank it goes 'boink' when it's up to pressure, so I can see/hear what's going on. 

But I've gained another job for my to do list. I switched the power back on and didn't get any lights on the dash. Turns out I have a loose connection or plug behind the dash. Or it could be a dodgy earth. So I need to get back in there and see what's going on. That's all started since I added the protective sleeve, it was fine before then! 

Saturday, 17 January 2026

Camber and spacers: fixed

 The blocks got cut, welded, cleaned up and fitted;




I might tidy them up after IVA but just for now it's the biggest surface area I can use. The camber on both sides is closer to 1.8 so that's dropped a fair bit, although not quite the 'zero' that would have been preferable. The bolts went back on fine and everything is nice and secure.

A couple more things now for IVA. The fuel tank is full;

Although I really don't remember petrol being green coloured... I'll just assume that is all the detergents and stuff that goes into modern fuels. 

I also wanted to take a photo for the fuel hose markings;


R6 fuel hose is suitable for up to E15. This is a 15% ethanol which I would be avoiding anyway, not least because I don't think the engine would like that high an ethanol rating. The tank is full of 10%, I could go to 5% if it's not happy but for IVA it's good. Maximum fuel pressure is 50 PSI, with the Mazda fuel pressure regulator keeping around 43 PSI in the fuel lines. I think I'd have to upgrade it if I went for forced induction. 

Next thing, handbrake efficiency. While I can't test the exact numbers, I did test it by using my torque wrench at each click. From 0 clicks I measured how much torque is needed to turn the wheel each side. 1 and 2 clicks gave it a slight drag, 3 to 5 seemed fairly progressive. I did see the right hand side come on slightly quicker than the left but it doesn't seem significant. Then by the time it got to 7-8 clicks, I was tightening wheel nuts rather than turning the wheel. The Mazda original required roughly 7 clicks, so I'm happy with that. There's still reserve travel, and I could adjust it slightly if required, but I don't want the pads to drag. 

One of the last things I need to figure out is the visible chassis rails in the interior, as per this pic;


According to IVA they come within the 'specified zone', so must be 2.5mm radiused. Now, the natural curves on the corners are close to that, but I still have doubts on whether they need something covering them. To be fair, I've never seen those covered or padded on other Haynes roadsters, but they're probably a bit more exposed on my car. 

Is that it? I've gone over the car multiple times, and no doubt I'll go over it again for the next few weekends. 


Monday, 12 January 2026

Camber and spacers

 This is another of those jobs that started as a five minute fix and has escalated into something much bigger. Essentially I want to get rid of this;


The 'stack of washers' is on the rear suspension and is used to adjust camber. It's a pretty simple process, add washers to increase camber, remove them to decrease it. However I'm not going to be taking this on a track and chase lap times so there's no need to change it frequently. So I want to replace it with something a bit more stable. 

The mechanism will still stay as is, but what I want to do is reduce the leverage imposed on the bolt. It's probably overkill (and the 'unsprung weight' addicts will hang me out to dry!!) but I want to increase the surface area of the join between the two plates. There's no benefit to going larger than the smallest side (upper in the photo) so I'll make a spacer to suit that size.

The main issue is material, and this is where the worms started pouring out of the can. The current gap is 18mm, but I have no stock that thick. I can't use tube because it wouldn't be any better than the washers, and buying stock without the ability to machine to the correct size is a bit pointless. The biggest I have is 5mm plate, but of course 18 doesn't divide by 5 so I'd need something else as well.

Or would I? Now, I've not measured camber for a while, and now the fuel tank is 95% full it's a bit heavier on the back. So on the weekend I measured the camber front and rear;

  • Front left -4.3 degrees
  • Front right -1.9 degrees
  • Rear left -3.7 degrees
  • Rear right -4.2 degrees
First thing that jumps out is the front left, that's way too negative. That needs the upper adjustment to be opened up one turn. Of course, doing that I'll need to reset tracking AGAIN! 

The rears are far too negative as well, I'd prefer -1 or maybe even zero. The difference between sides isn't too bad so I can do the same process for both. 

But what is the process? Well, I simply need to round up! Given that I wouldn't have been able to make an 18mm spacer I have to use either 15mm (3 plates) or 20mm (4 plates). I'm not sure what that extra 2mm will give me, but it won't be enough to push it past zero. Best guess I'll end up with about -2 both sides which would be fine. 

So I need eight plates made up, which I'll then test fit to check, but ultimately weld up in a single block. That will ensure the bolt is only loaded with shear forces rather than bending forces. As suggested I'm sure Mr Champion will be turning in his grave when I add a seemingly innocuous block of weight, but at least it won't be coming off anytime soon. 

Just one last note, the possibility of rotation and unscrewing. It had occurred to me that tiny movements in the bushes on both sides 'could' allow the nut and bolt to unscrew. But the top wishbone isn't subjected to twisting movements which discounts that side straight away. The upright is subjected to significant twisting movements by braking, but that rotation is turned into linear motion when it gets to the upper wishbones (well, it's linear in two directions but the wishbone allows movement up and down). Obviously I'll keep a check on things but with various areas of friction, a really tight bolt and a nyloc nut I can't imagine this going anywhere. Even if somehow it gets loose it would still function as a wishbone. It would have to come all the way off (or snap), and of course the same could then be true of any other bolt or weld on the chassis. 

Over the weekend I cut a length of steel to 45mm wide, enough for eight plates. Hopefully at lunchtime I'll cut it into 65mm sections then drill through the centre of all of them. To keep them in line when welding I'll simply use a spare bolt to secure them straight. 

Thursday, 8 January 2026

Brake routing doubts

 As expected, the time between IVA application and the appointment itself is giving me far too much time to overthink things. This time it's the rear brakes. After trying multiple ways to route the brakes, I couldn't get to a point where the brake flexi and the handbrake cable didn't want to exist in the same time and space. Not without getting close to other moving parts either. Even I know a flex cable won't last one rubbing on a driveshaft or a wheel.

So I came up with a plan to clamp the cables together;



Given they're both travelling in the same direction when the wheel moves up and down, it made sense to me. This way instead of trying to keep them separate, I tightly clamped them together. The cables don't move inside the clamp so they can't wear. 

But something tells me Mr IVA won't like it, it's not exactly a conventional approach. I've pinged the question to the LCB crew to see what comments I got back, I suspect they'll also be displeased with my solution. Of course it might take a while as LCB isn't as active as it has been. 

Just looking at the photos above I was trying to think why it doesn't route downwards and come back up to the caliper. I have a feeling that the routing ends up interfering with the suspension. (Edit) Just going back on old photos I can see down isn't good



On the caliper side it interferes with the bleed screw and slide carrier, and on the chassis side that's roughly where the driveshaft needs to live.

The other option is to replace the flexi with a shorter one that has a right angle banjo, so it comes straight out from the wheel towards the chassis. That's possibly the best long term solution but there's a money and a time element to that. Getting custom brake lines isn't a quick task so I've contacted Furore to see what their lead times would be. 




Tuesday, 6 January 2026

Conduit and IVA photos

 Well, the conduit went on fairly easily, although it was remarkably sharp and extremely springy so by the time I'd wrapped it round the wiring my fingers were torn to shreds. It also appears that I took very few photos! This is probably the only one that I have


And this is only here because it's a photo of the gas cable clip. Here's a wider angle showing the position of the cable as well as more of the wiring and how it's pinned in place


Note the nut cover on the first photo, I am hoping that catching little details like that will demonstrate that I've really thought about the car. 

Other details now, this is the wiring under the dash


I often wonder why my engine bay has so much visible wiring, it's because most other builders have the bulk of the loom underneath the scuttle whereas mine is a bit more on show. I might hide it away perhaps, after IVA.

So yet more bits for IVA. First some photos, here's the roll bar bolts. Nothing spectacular here but I wanted to take photos of what was underneath the covers before I permanently attach them. Yep, they are now fixed in place with silicon which is 'probably' removable given enough leverage but they won't be coming off when the car is being driven which is my aim. I'd already tested for radius so I was happy the covers were doing their job, it was just whether they were secure. 



Using silicon for the corner trim in the cockpit has also improved things there, the corner trim feels so much more secure.

The next three photos show the uncovered transmission tunnel, this is mainly for IVA but I suspect the inspector might want at least one cover removed to see in person. 





Photos from within the tunnel again, this time of the hidden side of the fuel tank. If the car is up on ramps then the same can be seen, but I wanted some photos here to make sure everything is visible




This last photo shows the fuel pipe routing, I can't see another point where it can be fixed before it gets to the swirl tank so I'm hoping it's good enough. 

Seat belt bolts on welded plates inside the transmission tunnel. The rear fixings are visible from the wheel arch, the outer ones can be seeing by kneeling down. This is just to show the most inaccessible ones




What else has been done... I've gone back over my IVA application, and yet again flagged the challenge I had with the website. It's awful, I can't even go back into my application and look at what I had put! I had to start a new application (yes, my fifth application now!) and rely on the browser auto complete options to get the details I entered. At least now I can add the application details to my IVA build diary.

Oh yeah, the build diary. That's something else I'm putting together, basically it's a summary of this blog but in IVA manual order. I'm hoping that whatever questions the inspector asks will be to hand and get me that closer to a pass.

On the subject of getting closer, the trailer is now booked. I found a place in Lichfield that does trailers, I think with insurance for a 48 hour hire it'll be around £150. That's a Brian James double axle. I'll be picking it up lunchtime of the day before and returning it lunchtime of the day after. That means I can spend as much time as required on the day, without having to worry about getting the trailer back before closing time. I am still a bit nervous about towing, having never done it before, but I suppose there's a first time for everything. I've checked my breakdown cover as well, they cover trailers if my car breaks down, but not if the trailer itself fails. The trailer should be decent condition though, it's not as if I'm buying a lump of metal with wheels off eBay. 

Now, what's left...

  • I want to try and get the brakes hot to see if they're consistent. I might even try and get them to lock up if possible (fingers crossed the fronts lock first).
  • Similar with the handbrake, I want to check it works evenly across the rear wheels. This is a bit easier as I can do it with jack stands, I just need the current snow and ice to go away.
  • Engine light from the ECU. I wanted to see if there was anything coming from the ECU engine light pin, in theory there shouldn't be anything (and I don't even know if the 1.6 Eunos had an engine light!) but at least I'd like to check it. 
  • Front leading edge. It's the last radius edge I need to check, so two minutes with the 2.5mm radius and possible a file should resolve that. 
  • Fuel tank needs to be full. It's nearly there, I can see fuel through the filler pipe. One more jerry can of fuel will be enough. It's not going to be 100% full as the filler is on the side, but hopefully that will be fine. And I suspect some of the fuel will be used during the test.
So really not much, and to be honest if I was doing the IVA tomorrow I doubt the above items would matter. Not having a trailer would be a challenge but it's just hypothetical!

No doubt every weekend between now and February I'll be in the garage checking everything over multiple times. But I think for now there might be a pause in blog posts. Shame there won't be a similar pause in my anxiety levels, I think they're just going to carry on increasing as I get closer and closer to the day!




Wednesday, 31 December 2025

Extra job, wiring conduit

 I'm going to blame the MK IVA videos for this one! So far my wiring has been bound and clipped as required, but many of the IVA videos and other guidance have had the wiring in conduit. I've often thought it was overkill and I didn't bother. For the engine wiring it's in conduit as it gets from the chassis to the engine, mainly because that's where the most movement occurs. Where there's movement, there's possibly wear and breakage. 

All the way down the side of the car for the front and rear lights it's just bound wires because the wiring doesn't get any abuse as it travels. Now I'm in my 'overthinking everything' phase I am thinking for the sake of a tenner and a couple of hours effort it's worth just putting in some split conduit. All I would be doing is cutting each clip zip tie in turn, putting the wires in the conduit and strapping it back up again. The most challenging step would be the wiring in the side of the car where it's really awkward to reach. 

So yeah, I'm going to add that job to my list, as soon as I can find a decent length of 10mm conduit. I can't turn to Aliexpress, even if it's the cheapest it would take far too long to arrive. If I get it from Amazon I can have it tomorrow and get it fitted by the weekend. 

And of course, while I was just looking at the car, I found this;


The unsecured throttle cable that I needed to sort but have managed to completely forget about! That'll just need a 3D printed clip or similar to keep it away from anything metal. 

Right, Amazon shopping time...

Tuesday, 30 December 2025

Exterior projections / mirrors

 I have surprisingly few 'exterior projections' to deal with, a lot less than an average Locost or Haynes Roadster. With the suspension entirely enclosed that removes a whole load of work. Overall the only things that are considered projections are;

  • Lights
  • Roll bar
  • Centre mirror
  • Wing mirrors
  • Fuel Cap
  • Boot hinges and lock
  • Bonnet bolts

The lights were sorted a while back. They all comply as they are, except for the reverse and fog that needed rehousing. That's all done.

Roll bar needed a bit more work, the 3D printed covers do the trick though. 


Given the touch points of the sphere they're probably a bit overkill, but it was just easier to do them as one unit either side. The seat belt mounts are similar, and that's all that can be contacted.

The centre mirror was all over the place, it needed a full back cover to protect it. However that same cover also prevents the sphere from touching the lower fixing so no more needed there.



The wing mirrors were mentioned in my last blog post and also needed a decent amount of work to comply. 

The outer edge of the glass was less than 2.5mm so it needed something. The clamping bracket might have been ok but I didn't want to risk it. 


I'm happy with how they both came out. The ring around the outside is a press fit and will not budge, and the centre bolt bracket tightens up with the bolts. Ironically the 'pointy' bit at the front is compliant, and (just) meets the 2.5mm radius requirement


The fuel cap was bought as an OEM mini cap so nothing to be done there. Similar with the boot hinges, while they are contactable on all surfaces by the sphere there are no sharp edges to deal with.

The boot lock was a potential one, while the outer edge was rounded the underside and the bolting plate 'could' have been an issue. A quick sphere test shows the only part contactable is the outer edge so I'm happy that will pass.


And lastly the bonnet bolts, which I have covered before, literally and figuratively. 

I also did the floor line test today, as expected the rear and sides are of no concern but the bottom lip on the front constitutes the floor line. Having a quick feel along the front edge shows no particularly sharp points but I'll get the gauge on there and see if I need to give anything a sanding. That's all it will be though, I don't think there's enough exposed edge to warrant the push on trim. 

Another job completed today was the correct attachment of the interior trim, using silicon sealant instead of tape. I need to let it go off before removing the excess but I'm 99% sure it'll be secure enough to pass the test. 

I also need to let it go off to finish a job I remembered a while back, trimming the handbrake cable. I left it with a long tail so it's good to trim it to length now. I'll also take a few photos with the panels removed, I suspect Mr IVA will want to see inside the tunnel anyway but I'll take some photos as well. 

Christmas IVA tasks

 We're post Xmas-madness, but thankfully I'm still on leave until after New Year (and my birthday!). And yes, it's more IVA work. 

So first job was figuring out whether my regular car was suitable for towing. It had a Westfalia towbar when I bought it, and it's a Skoda Superb so it should be very capable. Unfortunately I've never used it since I bought it so I didn't want to turn up to the trailer rental place and have it not working. 

I bought a 'test device' off Ebay that should have checked all the connectors. Unfortunately it failed miserably, no sign of anything which got me very worried. Going at it with a multimeter didn't improve the situation. Fortunately my brother in law tows on a regular basis so he had a tow board I could borrow. Plugged in, lights on, job done. As far as I can tell the tow bar electrics 'detect' when something is plugged into them, so testing without a proper board or some other device was doomed to fail. But at least now I know that the car is ready to tow. The ball itself was much easier, apart from a few hours to find the key that went on with no issue.

Back to the car itself. The telltale lights had blurred slightly during their first fit. The issue was that I'd printed the symbols on the filter as well as the lens to make the symbol as sharp and as black as possible. Unfortunately as I was fitting them one of them slipped, so instead of a really sharp image I had a permanently 'blurred' option. No biggie, I just open them up, rearrange them and put them back together. 

Then I found an issue. The handbrake telltale had melted the housing. While I knew the bulbs would get warm I didn't expect them to get hot enough to melt the housing. 


It still did the job but I was worried that eventually it would damage the bulb. Once again my brother in law came up with an answer. He had a light unit on his GTE that was very similar design, but with a few differences. First was that the bulbs weren't right up against the glass, they were about half an inch behind the glass. Secondly they weren't totally enclosed, each hole had a slot top and bottom for airflow. After comparing my solution with an OEM design I could see that butting the bulb up against the glass and completely enclosing the bulb was just a recipe for disaster.

So I copied both ideas, here's the CAD version of the new holder;


I also reprinted the images to get a tighter fit and prevent the 'blur' that kicked off this whole process. Now I'm hoping that with a bit of free air all round the bulb it won't get hot enough to melt the holder. A quick test run suggests much more sensible temperatures, well below the glass transition point of PETG.

Of course none of that was strictly an IVA issue, but better to be safe than sorry. What was an IVA issue was that the glass and dash surrounds weren't fixed and could 'potentially' fall out (despite being incredibly tight fitting) so they have now been glued into the dashboard rather than just pressed. 

What was potentially an IVA issue was the wiring brackets. I mentioned last time that I wasn't happy with the brackets, they were prone to bending and weren't a proper clamp. A quick design later and I had thicker brackets and a proper clamp at each point;



I'm much happier with these, they're a proper clamp for electrics and plumbing, with decent separation and routing. I had to put a pad inside them to get them properly tight but that was just a tolerance issue. I just need a dab of thread lock on the nuts as I don't have nylocs that small (the nut is on the back side, not in the photos). 

On to the mirrors next. I have already covered the back of the centre mirror as that was a guaranteed IVA fail. But the side mirrors were worrying me. I think they should be find but I don't want to be doing a trip to Bristol twice if I can help it. So I printed another back cover for the side mirrors.

While it looked 'ok' they didn't stay put. To get the tolerances tight enough to do the job and improve the radius's, it stopped the movement from working. And as per IVA, the mirrors need to be adjustable.

So instead of a full cover, I'm going for an edge trim and a nut cover, it might look a bit odd but at least the important parts will be sorted. Of course I was trying to design and print them last night, and after the third prototype failed to clip properly I gave up! I have a nut cover but the edge trim needs a bit more work today.

Talking of edge trim, up until now I had been pretty happy with the edge trim in the interior. It seemed secure and definitely did the trick. Problem is when I was reviewing the IVA manual for the 40th time to sort out the mirrors, I found an excerpt;

that are held in place by being stretched on or attached by double sided tape or other inadequate means

And guess what I'd used for the interior trim! Yep, double sided tape. To be fair it's actually carpet tape and ridiculously sticky, but doing my best impression of an IVA tester showed that it wasn't good enough. Certain parts of it felt loose, and while it seemed secure overall I'm guessing a decent tug would show otherwise. So I'm going to remove the current solution and replace the tape with silicon sealant. That will be an easier bond and will be 100% the length of the trim. It's still 'stuck on'  but then I can't avoid using adhesives completely (some of the other bits of trim are stuck on rather than screwed on so I'd fail there as well)

The other job I want to do is the 'floor line'. To define a vehicles lower edge, they use a 30 degree cone all round the vehicle and see where it touches the car. This theoretical boundary is then used to check exterior projections. However the floor line itself is part of the project test, so it must have a 2.5mm radius on it. 

That's all fine for the sides and the rear, as the bodywork curves underneath the car. Even if the 30 degree cone touches the extreme corner on the side, it's still an appropriately radiused edge. My concern is the front edge. It's essentially a fibreglass' end and wasn't particularly well finished from the factory. Indeed, to even get it looking the same either side I had to do some work on it already. 

So the plan is to make a 30 degree cone (well, a wooden triangle at least!) and see what the floor line actually is. I'll check all round the car but I suspect the remedial work will be limited to the front. 

I've also printed a 100mm ball to double check a few things. I was going to print a 165mm ball for interior projections, but to be honest I'll just check it all with the 100mm sphere. 

Next week will be the first week back to work so I'll get the trailer booked. It's a little over five weeks to the test, and while I can't imagine much more work going on with the car, I'm still expecting my brain to be working overtime and checking every little detail.