Dash back together and seats update

The dash is now back together, the reset button looks good and the defect on the edge is pretty much gone;

The car has been cleaned and ceramic coated so I'm ready for Saturday. 

In the meantime I had a go at profiling the seat. It does look like for comfort I need to bring my knees up quite a bit. A fellow Locostbuilder sent me a link to a thesis where it talked about seat positioning, this is one of the photos;

This also confirms the amount of knee angle that I should be aiming for. Even in this picture the pedals are lower than the seat, whereas for mine they're at the same height.

As a guide I tried some rolled up blankets as bolsters;

This is a 3 inch roll, and while it helps it's not enough. Also that's based on the back of the seat still being the same height. Adding a second blanket gave me this;

I think this is on the right track. The seat base is 18 inches deep so I'm thinking;

• First 6 inches will be a 1" thick pad
• Middle 6 inches will be a 3" pad
• Last 6 inches will be a 5" pad

Given that I want as much of the 5 inch pad as possible, I'll profile the other two layers to come up and meet it. This sort of stack (side view);

Even that might be overkill. For example many tintops just have an edge bolster for support, like these Porsche Recaros;

Or Cosworth recaros;

So I could do this;

The final option is the 'messy' option, which is a bag of PU foam and a bin bag! That would be to form a well fitting seat while I'm sat in the car. I'd still need to bump it up a bit, the expanding foam would only fill gaps where my butt wasn't touching the floor but I still want to have some padding for my back side.

I did have a thought that I could 3D print a seat pad... I have TPU and I reckon maybe 10% infill might work. I'll print a test piece and see if I can sit on it comfortably. 

Hot weekend

Well, the good weather is seven days early but fingers crossed it'll still be warm next week. This weekend it's up to 28 degrees on Monday. This will be the time when I figure out whether an all-aluminium interior was the best way to go. It did occur to me that the edge trim in the car is 3D printed, and while I left them on because they looked good, I also have doubts on whether they can survive high temperatures. Even the glue fixing them on could go a bit 'gooey'. If it does I'll just remove them, they were going to be removed anyway so it's not an issue. 

In any case, I'll get the car out and see whether it becomes unbearable in the heat. When my next post is 'third degree burns on my hips and elbows' then you'll know things got too hot!

I did discover why my diff was pretty dry though. Basically as soon as the propshaft was removed the oil would have come out, so it would have been dry since it went on the car. Such a daft thing to do and hopefully I've not done any terminal damage to the gearbox. If I have then it's <£100 for a new one, but it's not a few minutes job. 

Lets see what's on the 'to do' list;

• Heel/foot plates. Both passenger and driver need somewhere to rest their feet, it's surprisingly hard work to keep straight legs. It's mainly going to be just a bar across at an appropriate point, a bit closer on the passenger side with the driver side being just before the clutch pedal. 
• Reshape seats. Along the same lines as the above, I want to tilt the seats back or create a bolster under the thighs. I still have some pleather so I think some decently supporting foam would do. I did think about an old angled pillow that we have lying around but it's not actually that supportive. I've learned that seating actually needs to be a lot harder than you might expect to be comfortable. I can see why some seats are basically solid, or at most with a small layer of foam. 

(Later that weekend)

Well, heat is heat, and driving in a car with no roof or cooling is like having a hot hairdryer in your face. It's mostly a nice experience, but I didn't last many miles. On the subject of miles, I've started a fuel spreadsheet. Yeah I know, probably the epitome of dullness. But without a fuel gauge I need to have an idea how far I can get.

A 5.7 gallon tank gives me around 200 miles range. Just as a comparison, Malvern is around 50 miles away so I can get there and back without filling up. 

More work

 Bodywork fixes are looking good;

I'll need to rub down the paint once it cures but it looks a lot better already.

While the dash was off I had a look at the odometer reset button. After several hours of looking for the parts, I put things together and planned out where it would show on the dash. Then a few hours redesigning and printing the bezels got me here;

It looks good with the speedo temporarily behind the bezel, but I can't put everything together until the paintwork is polished and finished. I'm optimistic it will work well, then I'll be able to use it as a fuel gauge. 

I'm on countdown to Malvern now, two weeks to get it spot on. I'll do the paintwork in the week and get it all back together, then one last run on the weekend to make sure it'll make the journey. Then a clean and ceramic polish to finish. 

Gearbox oil, jacking point, wiring clamp, bodywork fixes

 I got lots of little jobs done yesterday. Start with the biggest one, the gearbox oil. 

I've wanted to do the gearbox oil for some time now, I'm aware that I've replaced all the other fluids except for Gearbox. So I bought a couple of litres of the recommended GL-4 oil and had a look at what is required. While the job itself is quite awkward on the MX5, it turns out the drain and filler plugs are both accessible from the engine bay in my car. The filler plug was first, that needed some persuasion but came off in the end. The plug itself didn't show any signs of issues apart from 20+ years of gunk. I'm 99% sure it's never been changed.

The drain plug was similarly easy to come off, and that's where I found an issue. It turns out there was very little oil in the gearbox, nowhere near the 2 litres that should have been in there. Once it was refilled and the plugs went on, then the job was finished but I wonder how much damage has been done by the gearbox being empty. I suspect sometime in the near future I'm going to need a new gearbox, at least for now it should be happier. Second gear is still the noisy one so I won't push it. 

That was the main job I wanted to do this weekend, and it turned out to be a lot quicker than I thought. 

I actually started the day with the rear jacking point, partly because I thought I would need it to do the gearbox oil. The jacking point was pretty straightforward, although my welder was not happy for some reason. Lots of sticking wire and burn backs on the tips. Part of it was welding upside down, but I think I'm overdue a new tip and shroud anyway. I'll do that before I need to weld again.

So I now have a rear bar in the right position for the jack, which should make lifting the entire rear a lot easier. No pics unfortunately, I seem to be forgetting photos of work in progress.

The next job was the wiring loom clamp on the engine. The one above the exhaust had melted and distorted so it needed to be replaced and reinforced. The design is as before, but now I have a layer of 1mm steel round it to keep the shape. Once it was all bolted together I could see it was going to be a bit stronger, and at least the wiring and the coolant pipe that is being held by it won't drop on to the exhaust. I'll still monitor it to see if it's sufficient, I may have to upgrade to ABS if this isn't good enough. I don't like printing in ABS mainly because my printer can barely cope with the temperatures, and it warps really easily. 

The last jobs were the bodywork. Just under the passenger dash I had a scratched panel where I managed to drop it during fitting. It shouldn't have bothered me but I found I was looking at it every time I drove. It actually took a lot more work than I thought as the scratches were quite deep. Still, half an hour of sanding and polishing got it back to 'nearly' sorted. I left the panel at 1200 grit as I don't want the panel shiny. 1200 grit is roughly where it started, a slightly matt finish with no swirl marks. 

The other mark on the bodywork was again on the passenger side, a dent where filler didn't work properly, and then the paint also chipped. It's another thing that I didn't really need to fix, but I've done it anyway. Or at least I'm halfway done. I filled the hole yesterday, I'm about to go at it with some sandpaper to get it flush, then touch it up with some paint. It is just pretty labour intensive work, a couple of hours at least I reckon. But it'll be worth it. Again it's because it's so close to the passenger seat that it's very visible.

I'm also tempted to have a look at the odometer reset button, just see how much work it would be to restore it. It would be mainly replacing the 3D printed part, as well as cutting a small notch out of the panel. I just need to make sure I can get it in the right place. 

Oh yeah, and the rev counter is bouncing again. I am hoping it's simply a bad connection, but I suspect it might need a new one. 

More miles, first issue

More miles now, and a full tank so an opportunity to work out my mileage again. 

The first journey from full tank to full tank was 102.5 miles for 12.3 litres, which works out to be 38 miles per gallon. This fill up was 21.23 litres and it got me 162.8 miles, which is 35 miles per gallon. Given the first was motorway and the second was 'fun' it looks about right. 

Now the issue. Coming back home I got a clunk clunk under the car right under my feet. Everything seemed ok so I got home and had a look;

 The tensioner bolt for the alternator has decided to undo itself and escape. Thankfully it's just a standard bolt so I'll replace it with some threaded rod and some nylocs so it can't go missing again. Nothing else looked loose so I'm counting that as a win.

Oh yeah, and I forgot the main thing about an open top car... sunburn! My face feels like I've been in the sun for hours, I assume it's a combination of the actual sun along with the drying effect of the wind. 

I also want to look at a jacking pad for the rear. Something in the centre within reach of my jack would be ideal. At the moment it's going on one of the boot supports;

It works but it's sketchy and lopsided. If I put a bar or flat panel at roughly the same depth then that'll be a centre lifting point. With the jacks just ahead of them it works out quite stable;

The front should also get similar treatment although I don't have many ideas there as the front of the car hangs down too far for the jack to get under. 

First 50 miles

 This morning dried up so I thought I'd take the car out on it's maiden voyage. A quick first few miles and back showed everything looking good, no leaks and no spray of diff oil so that's all sorted. A short wee break and a few more miles, visiting various relatives on the way. Everything seemed to be quite healthy. There were some unusual 'smells' but I can't tell whether they were from the car or from the outside world. After all it's a UK spring and all sorts of stuff happens!!

Once I'd got back and got the feeling back in my legs (heel rest and seat pad to be done very soon!), I had a look under the bonnet and round the car.

Firstly the screens worked well. I no longer have the draught on the top of my legs which was part of the wind chill I had from Bristol. I still get some wind buffeting in my face but it's tolerable to drive without a helmet now. I tried a few different screen angles but it turns out the one I had that 'looked ok' is actually the best one. So that's a huge tick in the box for getting to the kit car show.

Everything under the bonnet held up well despite the additional heat. Well, apart from one bracket. It's PETG but it's right above the exhaust, and it's in tension rather than compression;

 I suspect if it gets any more pliable the coolant pipe will become detached and drop on the exhaust. I need to reprint a new bracket and then encase it in steel, similar to what I did for the fuel pipes. 

Oh, on the subject of fuel pipes, no petrol smell anywhere. That particular demon has been well and truly exorcised.

The main thing that I think needs some work is the rear suspension. I modelled the upper wishbones off a Westfield design where the MX5 upright is next to the damper;

The problem is I then also included a camber adjuster;

I was thinking that the damper and the upright were close enough to not put rotational forces on the bracket. Unfortunately I was wrong, it is basically twisting the bracket on the bushes. It's not enough to unwind the bolt but at some point something is going to get upset. 

I have replaced the washers above with a solid plate as below;

But essentially what I need to do is make the wishbone wide enough to accommodate two bolts. The second bolt will then provide the shear strength to prevent rotation. That then gets me back closer to the Westfield design. The fact that Westfield used the design at all suggests it does work with the right layout. Another Westfield design also puts the damper off from centre;

As a short term fix I could just weld the plates together, but that won't allow me to change the camber and that's on my 'to do' list. I am wondering whether I have enough material to redo them entirely, including enough on the wishbones so I don't have those spacers (but still have the option of camber adjustment). I may have the bush tube but I am 99% certain I don't have enough of the seamless tube. 

Then I'm wondering whether I should change the design so the damper is directly above the upright so forces get transferred in a line rather than rotationally. But then I could make it so the joining plate is horizontal rather than vertical. 

I guess some planning/design is in order.

(The following morning) so I'm having an early morning conversation with Copilot... yeah I know. Copilot is only as good as the questions you ask it. In this case I asked what the friction force was for the plates, and it came back with around 400lbft of torque required to overcome the friction of the steel surfaces. That's on a fully torqued M12 bolt with clean surfaces.

The second question was how much force would be applied if the shock absorber was 1 inch away from the pivot. The response was 80 lbft. Now just looking at the photos I can see it's a little more than 1 inch, but at this point it's just about multiplying the numbers. In theory it would have to be five inches away to apply enough force to overcome the friction. It's not five inches away so I 'should' be in range.

The last question was 'how to improve it', and there were two options. A friction shim or a shear pin. The friction shim is basically some other material to increase friction. Think brake or clutch pad material, that sort of thing. It makes sense but a quick google suggests I can't exactly buy a 'sheet' of this material. 

The shear pin is a much better option for this application. Basically a hardened steel pin through the two suspension pieces and the bracket in the middle. Two 6mm pins would work fine. If I can't find long enough pins to get through all the plates I'll use ones on either side and rely on the welding in the middle. So I need a maximum of 8 pins (2 per hole, 2 holes per side, 2 sides). The standard quoted is DIN 6325, and while Amazon is showing me furniture pins, Ebay has some listed for less than a pound each. I still have a couple of weekends before the show, and apart from taking the rear suspension apart this isn't major surgery. I'd have it done in half a day at most. 

The one thing I want to do today is to get the car lifted up and get the brackets realigned and retorqued, just in case it was something silly like the lack of torque on the nut. I also want to clean off the paint in case that is acting as a lubricant. When I was getting the torque figure it was based on clean steel with flat mounting surfaces. Those surfaces aren't clean or flat, so again this means the pins will work better than just trying to increase the friction. 

I have a registration!

I have to give credit to the DVLA people, they really turned things around quickly. Between paperwork and registration being assigned was 13 days. It would have been quicker if the postal service had delivered an information request on time (6 days for a letter to arrive, how is that good service?!). 

So now I have an age related plate, or at least the email confirming it. I still have to wait for the paperwork to arrive (by post!) before I can go buy my number plates. I was going to get them online but to be honest buying them from a shop is only a couple of quid more expensive. I really can't wait now, screwing the plates on will be the final step in getting it roadworthy.

Of course, I'm sat here now with the beginnings of man-flu, and the prospect of a slightly damp bank holiday weekend, so it's not as if the postal delays are making that much difference. The paperwork didn't arrive today (Friday), and we tend not to get post on a Saturday so it'll be Tuesday at the earliest.

(Later that week) It's now Thursday and I've not had confirmation that the new cheque has arrived with the DVLA, and there's no sign of any paperwork. Seriously, can the postal service get any worse? I wanted to get a few hundred miles driven over multiple weekends before I head to the kit car show, at this rate I'll still be waiting to buy the number plates!!

However it is very reassuring to know that the car now fully exists;

It also shows correctly on askmid as insured. The donor car is also gone, that just returns 'vehicle details could not be found'. So everything online looks good. 

As I mentioned above I was ill over the weekend (it managed to stay with me from when I finished work on Friday until I started work again on Monday. This week has been slowly recovering back to normal, and hopefully I'll be getting some garage stuff done this weekend. One of the first things I need to do is take it for a drive and give it a shakedown. That'll allow me to check the new diff seals, the rear suspension, and the front screens. I also want to start doing some more work around fuel economy which again needs some miles driven.

The same also applies to the foot rest and thigh pad, as well as checking the passenger side footwell temperature. It's right next to the exhaust and I didn't check how hot it gets in the car because of it. 

(Friday update)

Well, thankfully the paperwork arrived today, and a quick detour to the local shop got me two new plates which got fitted after work;

So the car is effectively finished, IE it is a roadworthy car that can be driven. Of course it's not completely finished, I still have a fair few things to do as well as simply driving and enjoying it.

I didn't get to drive it tonight as it was raining, but tomorrow is looking dry. I've got a few hours in the morning to take it for a spin and see how it drives.

Windscreen done

From this;

To this;

Personally I think they've come up really nice, although time will tell whether they do their job. I've not done the bottom seal yet though, I want to test drive and see the effect. It'll also give me a chance to test various angles to see if there is a 'sweet spot' where the wind goes over the top. 

I've also done the rear number plate, this is version 5 (or maybe 6);

This one is just a small support that will disappear behind the plate. The front won't be mounted on anything, I'll just screw it straight to the bodywork. It'll need to be slightly curved on the front but that shouldn't be an issue.

The last job for now is just a small bolt cover in the boot, to cover an exposed bolt thread. It wasn't a major one, I just knew I'd scratch myself on it at some point.

I have also heard back from the DVLA. Unfortunately it's not a V5, it was a request for more paperwork. In my specific case, I'd forgotten to sign the cheque. So I've spent the last two weeks waiting for something to happen, when nothing could happen. Anyway, the signed cheque is now on it's way back so hopefully that will be fine now. They didn't ask for anything else so I'm taking that as a good sign. Maybe now the paperwork has been reviewed once, the cheque can be cashed and I can get my plates. 

Diff and windscreen

First job for the weekend was the diff seals. Autodoc got them delivered Saturday morning so I thought I'd have a go at fitting them. Just take the wheel off, pop the stub shaft and seal off, new one on, job done. Nah, not that simple unfortunately.

Despite my best efforts I just couldn't get the angle to remove the shafts, so in the end I took the diff out. Which needed the boot to come out. Not a big deal for either of them, just a bit time consuming. It was so much easier with the diff out though, the first shaft came out with a sharp thump;

Having it on the floor also meant I could put the diff on it's side to save the oil. The seal was toast which was a good sign;

A whole section in the bottom left was folded in. Even if the folded section had maintained a seal, the creases would have let oil out.

New seals both sides, then a quick top up. I reckon I got about 100ml of oil in before it reached capacity. Given a full diff is only 0.75 that was a decent amount but not so much that the diff was knackered. Well, at least I'm hoping that is the case!

Next job was a bit of painting. The steering column was looking a bit rough, as was some of the interior steel sections. A quick coating of matt black sorted both, hopefully once it's completely dry it'll protect a bit better. 

Then it was on to the windscreen. Starting from last post where I had cardboard cut outs, I printed the hinge and trial fitted the windscreen.

Straightaway I realised that the hinges were too chunky. I liked the idea of chunky hinges but together they were almost the width of the screen.

Then the second issue;

The curve of the car meant the screens were pointing out like ears. It was quite pronounced with the square glass but even with the rounded glass it was going to look weird.

So there was a few things to fix. First was the angle, that wasn't too difficult. A few trials with some spacers showed that if one side went up 3mm and the other side went down 3mm, the 6mm difference would put the screens horizontal. The second fix was just to make the brackets a lot narrower.

I've ended up here;

The screens aren't perfectly horizontal as that would look as out of place as ones parallel to the car. I think this angle is spot on. I'll set the angle at 70 degrees to start with, and have the lowest (inner) edge to be 10mm off the surface. The outer edge will then be 16mm. I'll leave the bottom wiper until the screens are on, just in case I decide they're not needed. I think they will be just to stop wind getting in from underneath. 

Oh, and the initial hinge design used Nyloc nuts to make things tight. That didn't work, it was just too stiff and I even broke one of the initial brackets tightening it. So now I have some TPU washers that should lock things in place. Of course, only a test drive will show whether it's strong enough so that will be a while yet.

In terms of fixing them to the car, as long as I'm not too close to the dashboard then there's nothing underneath to screw into accidentally. So only a few more fixings to go for the screens, basically brackets to screens and brackets to car. 

Next job is the rear number plate holder, version 4. I've took the old one off (with only some trouble removing the old sealant), now I need to print a reduced version. I'm staying with a full sized plate but I want to make sure there is no exposed support. The only exposed printed part will be the number plate light itself. That needs to be done as one piece so I don't have glue lines in it. I'll probably go for a centre piece big enough to fit on the bed, then just a couple of T pieces to provide side support. I'll also do a similar design for the front plate, obviously without the light. 

Random thought

Yeah I know, not exactly a revelation, but noteworthy nonetheless. The fastest car I have ever owned was a Saab 93 Aero. 2 litres of Vauxhall goodness with a bit of magic sprinkled on top, a very nippy car in my opinion. Helped by the fact that it got a bit of a tune up to 250bhp.

The only problem is that it wasn't a light car by any means. With a kerb weight of 1550kg, that gives me 161 bhp/ton. 

Now compare that to the kit car. The donor MX5 only has 113bhp, less than half of the Saab. But then it's kerb weight is 612kg, very much less than half. A quick calculation puts it at 184bhp/ton. So just on paper it's faster than the Saab.

Of course, there's lots of other factors on how cars get from A to B at a decent pace, but at least for power to weight it will be my quickest car so far. 

Just as a further comparison, a family member has a Mark 2 Astra GTE and a Mark 3 Astra GSi. The GSi works out at 135 bhp/ton, and the GTE is 155. 

I wonder what the 200+bhp kit cars feel like, if my lowly 1.6 is going to be a bit of a handful. 

Boot finished and windscreen started

First task, the boot is now finished;

I'll build up a toolkit to live in there, but at least now I have somewhere to put my helmet at the show.

Of course, while I as at the back of the car I remembered I wanted to change the rear reg plate mounting for something a bit tidier/smaller. 

Next job is windscreens. I started off looking at humps and deflectors, but then I got reminded that a wind deflector was only a temporary thing, and that I wanted Brooklands Aeroscreens as the final product. Now I'm done with IVA I can actually have the proper thing.

Now real aeroscreens are £200+ which isn't really an option. There is one option that is cheaper which could work;

Although I wouldn't have this green as it wouldn't match. But to be honest, the whole design can be done with 3D printed brackets and some acrylic. So I've ordered some acrylic, and time for a bit of CAD;

Yep, you guessed it, cardboard aided design. This is the shape of Brooklands curved glass at a decent angle, and it looks pretty much like what I want. I do need to make some brackets, and I can either go for something very Brooklands like;

Or I could go for a more basic option like the first option. 

Either way I do want to fill in the lower gap. It's not a huge gap;

So I reckon just a couple of mm of TPU would do it. To be honest I could probably leave it without issue but just for completeness a bit of trim will finish it off.

I did start with this as a mounting bracket;

The idea would be for some threaded rod to secure the screen to the car, it would allow adjustment of screen angle and (I think) look quite decent on the car. I'll need a bracket for the screen on one side and a tightening screw on the other. On both sides I'll use embedded nuts so I can apply a decent amount of torque to make things tight. 

Saturday progress

I've got a few jobs ticked off;

Boot liner installed and mostly covered in vinyl. I've used TPU supports to carry it on the chassis, as well as rubber strips on the tank to stop any vibrations and knocking noises. I need to trim the sides as a last step, once the adhesive has gone off;

Corner trim removed (I may have mentioned that in a previous post)

Mirror trim removed and tightened, again probably mentioned in a previous post. 

Steering wheel pad removed.

Indicator telltale. I printed a shade but it doesn't quite look right. It's slightly too large and curves round too far. Mark 2 to be designed and printed.

Indicators are back where they should be. I had to buy new lenses because the paint didn't come off, but I'm much happier with how it looks now;

The phone mount is in place but not powered yet. I only have one wire and I'm torn between doing the phone or dashcam first. The phone runs off a battery whereas the dashcam doesn't so it would make sense to wire in the dashcam first. 

And as expected, I've picked up a couple more jobs. Removing the pads inside the car has ripped some of the paint off, so I need to touch things up. I might do the entire inside of the passenger side to get it consistent although it would need to be done with a fairly small paintbrush.

The bigger problem is an oil leak. Or more specifically a diff oil leak. While I was doing the boot I could see oil dripping off the chassis. I could smell diff oil so I got the car up on axle stands and had a look;

It's a bit difficult to see on the photo. I had a nice spray of oil in line with the passenger side diff seal. It looks like reusing the donor ones didn't work. They're not cheap so I had hoped I could reuse them. Turns out I can't so I have had to order some more.

Although I did remind myself that I had an entirely different diff for free, and I've thrown away the case that would have had a pair of seals that might have been reclaimable. Ah well, can't win them all.

So once they arrive from Autodoc, I'll get both sides replaced and the diff refilled. I don't think it would have done any damage as not enough oil could have got out, but I'll see how much is still in there once I strip things down.

 

Completed car photoshoot

The registration application calls for some photos, so I thought I'd add them here too.