Sunday, 27 January 2013

I'm actually building a car...

Okay, so apologies for not having explained the various switches being employed as previously promised.  I've decided that I need one more switch and its not that interesting a topic anyway.

What is much more interesting is the fact that there are some panels on the chassis.  I'd left the chassis with Dave at Track Developments last week and he'd made plenty of progress getting most of the panels roughly cut to size and some of them drilled and virtually ready to bond and rivet on.  To this end we concentrated on fitting the floor and seat-back bulkhead.  To make subsequent work a lot easier however, it makes sense to get the internal panels cut and drilled where they attach to the bottom chassis rails as its tough to get the drill in once the floor is on.

Once this was all done, I ran a wet'n'dry contour sanding block around each of the panel edges and then degreased both the chassis and the panel.  The chassis then got a spray of wax oil in each of the rivet holes.  I appreciate that rust is unlikely to be the factor that determines when the life of a race car chassis is up but it can't do any harm and hopefully stops any swarf etc from rattling about.

I should mention that Dave had also put the chassis onto a clever rotisserie/spit that means that the chassis can be spun around without lots of muscle or damage to the powdercoat - it makes life so (relatively) easy.  At last it was time to squeeze some bonding compound onto the chassis.  I've used Car Builder's Solutions PU adhesive for years - its economical and really does stick like polyurethane to a blanket (don't ever wear tidy clothes when using this stuff).  You can abrade the paint to get a better key apparently but I've never found it necessary; not when you have a rivet every 40mm.

Here's Dave having a go with the PU - despite warming it up, it's hard work for the tendons in your wrist as you slowly squeeze it out of the tube - it's therefore great to be able to pass it across to someone else while you have a rest.
Then, having enlisted the help of local MEV Exocet builder Simon, the three of us carefully lowered the floor into position, adding a few clecos and rivets as we did. Roughly an hour later and it was looking spot-on.
We then repeated the process with the back panel, which admittedly was a little more awkward - we guess because the panel had shrunk by a tiny amount in the cold.
Finally, I simply slid the rear tunnel cover into place.  This is going to be secured with rivnuts and bolts to allow me to check the bolts on the diff.

Am I happy?  Too bloody right.  It looks great and we're actually constructing a kit car at last.  I don't know why I doubted the powdercoat colour now either.  I think it looks very classy against the aluminium.  I'll need to buy shares in Autosol to keep it that way, but we'll cross that bridge when we come to it.

In other news, the reverse 'slave' gear is back from HPC with teeth rounded and steel hardened - 6 weeks ahead of the quoted lead time.  Also, my Digidash 2 Lite with IR lap timer is imminent - this as come at an excellent price with bags of useful advice from Andy at AB Performance.

After a pretty horrible week, yesterday was a good day.


Sunday, 13 January 2013

British Racing Beige

I've realised that I'd failed to mention on here that, having procrastinated for ages over a the colour to powdercoat the chassis, RAL 1019 was only available with a significant surcharge.  The closest 'standard' colour available was RAL 7032 so I went with it.

Was this the right decision?  Mmmmmaybe.  I got back from a nice couple of days in Tuscany yesterday and at the first opportunity today headed over to see the chassis.
It's rather lighter than I'd originally planned.  The good news is that it will show cracks very easily.  The bad news is that it shows every slight imperfection in welds, joins, tubes and so on.  If this was to be my road-going exquisitely finished and upholstered weekend car, I'd be tempted to have it recoated in something a bit less stark.  In actual fact, this will probably do the job better than I'd intended so it's all good,  It's also pretty smart.
It's certainly difficult to photograph: in some it appears almost bright white; in others it appears mint green.
It has struck me that its actually fairly similar to the hue applied by Lotus in the early days of the Seven.  Since I was struggling to take a decent photo I wondered if a contrasting component might help.
Apparently not - the happy bi-product is however that I confirmed that final welding hasn't prevented the reverse motor from fitting.  This is a good thing as I've just sent the custom prop-gear back for tooth rounding and hardening.  The reverse now stands me at well over £600.  It'd better bloody work.

I've also bought the last of the 'dash' switches that I need.  I'll post some pics and info in a separate post later in the week.


Sunday, 6 January 2013

Rats' Nests

A parcel full of shiny things arrived on Friday from series sponsor and all-round nice chap Andy Bates of AB Performance.
The package on the left contains uprated clutch springs that, allied to new friction plates and steels, should mean that I am able to transfer motive force from the 16 valve Yamaha engine to the wheels via the gearbox, prop, differential etcetera.  On the right is a billet oil sandwich plate that will divert lubricant through the 25-row front-mounted oil cooler.  Judging by Austen's experience, the sandwich plate may need a touch more machining yet.

As suggested in the previous post, I think I've reduced the bike loom down to what I need.  The picture below shows roughly what's been involved.
The jumble of wires on the left is, broadly speaking, what I'm retaining to run the engine.  The jumble of wires on the right is what I've removed.  If you're eagle-eyed, you'll notice that the fuse box and relay assembly lie within the junk pile.  There are a number of reasons for this.  Firstly, I want to make fault-finding  in the paddock as simple as possible - as simple as possible for me.  While I can sit in front of a wiring diagram and suss-out that the clutch switch needs to be earthed and the tilt switch needs to be glued-up etc, the fact is that its all a bit of a bodge that I'm likely to get very befuddled by when I've got a short amount of time to solve the problem before the next race.  Hence, the relay assembly has to go.  I've actually done this before on a R1 without any major problems - albeit the R1 in question was a 2001MY 5JJ where the number of wires in the loom was about 1/3 of what is present on the 4C8.  Next, I wanted one fuse box that covered all circuits in a logical and easy to understand fashion.  The problem that I did have when I built the loom for my R1-engined MNR was that I struggled massively to put together a fuse box assembly that was neat and safe.  Help is at hand in 2013 however thanks to Car Builder Solutions and their wiring module, pictured below:
The unit above is pre-wired such that you generally just need to run the relevant wires from the other components.  The really appealing bit for me is that it sorts out the power distribution to each of the fuses which is where I struggled in the past.  The downside is that its relatively heavy but I'm more than prepared to compromise here for the sake of getting the wiring bullet-proof.  Of course there are a couple of small deviations that I'll be making., this is my car after all.  For example, I'm letting the ECU determine when the injection fuel pump should be powered-up as on the bike.  This therefore requires a relay.  There are two relays on the wiring module.  Nominally one is for the horn and one is for the fan.  Thankfully, since the bike horn is so small and efficient that it can be wired direct, I can use the 'horn' relay to switch the injection pump.  Ta-dah.  The other benefit of the wiring module is that the abundance of fused circuits means that I can split most things out onto their own circuits and hence make fault-finding easier again.  Others will probably have started from scratch (a bit beyond me) or have extended the bike loom (scrappy in my eyes) so I feel that I've made the best decision for me as the builder AND user.  It just needs to work now, which brings me to my final point on the wiring.  The original circuitry contains a zener/diode assembly to protect the ECU from voltage spikes.  I sort-of understand how this works and with the help of a couple of the chaps on Locostbuilders have hatched a plan to replace the assembly which was contained within the yucky relay box with a couple of electronic components.  I've also got to 'trick' the ECU into thinking that the tilt switch is still present using a resistor so as a result have a few small components to wire-in.
Tomorrow is chassis collection day which is exciting.  I just hope that I feel a bit better as I've felt dreadful all weekend - too weak to be able to remove the oil filter on the engine which is frankly pathetic.

Happy New Year by the way.