So, here’s a nice shiny picture of the final arrangement of the master cylinders, lurking at the bottom of the footwell.

There’s doesn’t seem to be much point actually putting any fluid in the brakes at the moment though, so I’ll leave that for a while. For all I know, I’ll find something that conflicts with one of the brake pipe runs at some point, meaning I’ve got to change the lines and I hate getting brake fluid on my hands.

As I was doing the hydraulics I ran the line to the rear for the clutch slave cylinder. I haven’t fitted the slave cylinder yet though. So, for the time being, I’ll just leave the line tie-wrapped up in position, as in the photo.

I still wasn’t too sure of the steering column positioning. I seem to have moved it around a lot and never been completely happy with it. However, this time I was determined to finish the job. Luckily, I think I’ve finally managed to do this. This time I’ve ended up using a completely (Escort) standard lower column and I’ve moved up the lower bearing mountings a bit more. This was getting a bit hard to do with spacers so I machined some bushes and welded them into a couple of bits of tubing that I welded to the chassis. (I know, I know…)

You can see all of these bits in the photo on the right. I really think that this is it for the column.

Mind you, there was one final thing to check in that I’ve moved up the column a bit more and there was always a chance that it was going to bash into the underside of the front bodywork. (Just what do you call the front bit of the bodywork on a mid-engined car? “Bonnet” seems wrong somehow. The rear bit is clearly the engine cover. Hmmm.)

So, I refitted the central tub and tried the front bodywork on for size again. The first problem was that front of the tub bashed in the fluid reservoirs as it was being lowered into position. This is because the roll cage requires that the rear part of the tub is put in position first and the whole thing “hinged” about the rear of the tub. Still, that wasn’t too big a deal with the help of a jigsaw. More dust in the garage though…

I said that I’d done all of the hydraulic parts of the braking, and that I have. However, that doesn’t mean that the handbrake is done yet. So, I then spent ages fitting the handbrake lever to the chassis, as in the photo on the right.

This might look a bit confusing as there’s a loop of cable. This is because the Wilwood calipers are a bit lacking in mechanical advantage for the handbrake so this arrangment gives a 2:1 mechanical advantage to the handbrake, at the cost of double the lever travel which means that you have to be a bit careful to adjust the cables so that there’s only a little slack in them. Experience from the Fury shows that that isn’t a problem though. As you might be able to tell from the photo, the cable comes out of the lever heading straight down. So, I machined a bit round lump of Delrin to run the cable around and bolted that in below the lever.

At the right side you can see the compensator that will be attached to the two cables to the rear brakes. I haven’t actually made those cables yet because I’m not completely sure how the cables will attach to the calipers. On the ones on the Fury I had to modify the levers on the calipers so that they didn’t bash into the inside of the wheels. However, I don’t know yet whether that’s going to happen on this car as I don’t yet have the wheels. I have ordered them though, Compomotive CXRs like the ones I’ve got on the Fury and as in the photo on the left. They haven’t arrived yet though. Until they do, I’ll hang fire on finishing the handbrake.

That’s all the J15 stuff. It may have escaped your notice, as you’re probably not as obsessive as I am, that the racing season is coming up full tilt on us. As it’s clear that the J15 isn’t going to be ready for the first race[s] of the season, I spent a while at the end of today just checking that the Fury still worked. I’ve got some more to do to it though before actually racing it. I wonder how you do it?

First up was fitting the steering rack, which took about an hour. I’ve done this several times now and I still can’t work out how Jeremy managed to design this because it fits with fractions of a millimetre to spare.  There’s a trick to getting it in, and every time I fit it I work out what the trick is. And then, being a chap with ages neurons, I promptly forget again. Oh well, with luck this time it’s there for a good long time.

Then, as at the rear, I broke out all the carefully labelled acetal bearings and fitted all the front suspension and hooked it up to the steering rack. I haven’t fitted the anti roll bar yet, because I need to work out exactly how to make that yet.

What I do need to do, as you can probably tell, is to chop that aluminium floor panel up so that the wheels have something to poke through. I don’t actually have the correct wheels yet, but some of the Fury ones will do in the meantime. The offset is wrong, so the track will be rather larger than it ought to be, but if needed I can move the car around.

Apart that is, from the really annoying problem that the taps I ordered turn out to be duff in that they cut, and then wrecked, the threads. So, that mounting block in the photo above has nadgered caliper mounting bolt threads in it. This means I’ve chucked away one set of taps, ordered some more from somewhere else and I’m going to have to generate a lot more aluminium swarf in order to make another mounting block. However, the whole process seems to work which is good. It’s just very annoying that I’m going to have to waste half a day hunched over the lathe.

I need to get the the chassis off to the powder coaters. I phoned them yesterday and they said they’d go a small problem in that their shot-blaster had had “relationship problems” over Christmas (! ) meaning that there was going to be a bit of a delay. That’s probably no problem as I’ve got lots to be doing. I’ll probably  try and take the chassis over at the back end of this week as I’m going to be dead busy next week anyway.

Next thing was to do the panelling over the top of the pedal box. However, I’m a bit unsure where the bonnet is going to be, so I put the pedals and steering column back on the car, and put the tub and, for the first time!, the bonnet on the car. It now looks like the photo here. (Except that the camera seems to get a bit confused about the colours.)

This means that I can now look underneath and have a look at how much clearance there is between the column and the underside of the bonnet, something that I’ve really  been guessing about up to now.

One of the reasons I bought the J15 is that I reckon it’s got a fairly small frontal area. That means the bonnet is low (and there’s no annoying induction lump in it).

As you can see, although the perspective is confusing, the suspension, positioned here at full droop, is pretty close to the bonnet, although there is about 30mm clearance so that’s OK. The steering column is well clear so there’s ample room to build an aluminium “tent” over the top of it.

After getting the chassis and other components ready to go to the powder coaters, that’s probably the next job. As you can tell, I’m putting off doing the rest of the really boring panelling.

At the right hand side of the previous photo, you can see the lower edge of the bonnet. Interestingly, there’s a substantial flat portion on the bottom of this bonnet. At first sight, this looks to be pretty much at the level of the bottom of the chassis. If so, that means I’ll be able to extend the undertray forwards so that the bonnet rests on it. I’m intending making it so that the bonnet just lifts off, rather than hinging things. As such, the undertray looks as though it’ll perform a couple of functions.

However, as I said, I reckon it’s going to be fairly easy to patch up the GRP on the inside as the aluminium makes a pretty good mould, as you can see in the next photo, especially with the addition of suitable release agents whether film or wax.

That all meant that I could fit the bodywork to the tub again and actually see if the steering column was going to fit or not.

With much faffing about I decided that I was going to have to shorten the lower column which actually turned out to be quite easy as I had some tubing of pretty much the right size to sleeve the Escort-sized lower column.

This photo is of the bottom end of the column once I’d done everything. You can see the sleeved lower column and  you could also see that I welded some little plates to the chassis to which to mount the bearings; note that I need some spacers to put the bearings in the right place. I’m still going to have to grind a little bit off the brake pedal pad, but only a small amount.

One issue about all this is that if I just assemble it as it it then I’ll end up being unable to remove the aluminium sleeves and bearings from the column. This is because they won’t fit over the welds that attach the spline at the bottom end of the column or the steering wheel attachment at the top of the column. I think I’ll just put up with that. I could grind the welds so that they’re not proud of the column tubing at all but that seems like a daft thing to do to what’s essentially a safety critical part of the car.

The thing is, I wanted to check the steering rather more carefully, and perhaps change the routing of the column a soupçon. In order to do that, I needed to check how it fitted under the bodywork. The problem is, I had to do lots of faffing around to get the central portion to fit over the cage; for example to allow the front hoops of the cage to stick through the bodywork, and also to allow the steering column to poke through the front of the central bodywork section. You can see both of these in the photo on the right.

The problem was, even to get the bodywork down here I needed to fit the rear portion around the cage’s rear hoop. I always knew this was going to be tricky as I’ve got the long wheelbase version of the chassis, which is 60mm longer at the rear. The problem is, the bodywork isn’t. Longer, that is. That meant that the rear section of the bodywork was pretty much in the same position as the rear hoop and that wasn’t going to work.

I discussed this with Jeremy right at the start and the original plan had been to split the bodywork around the rear of the central tub area where the shape is essentially a 2D curve. That means that it can be put back together with a 60mm spacer of some form without messing about with the shape. I had originally intended to leave this until a lot later in the process. However, as I was doing the steering it seemed more and more as if I was going to have to cut the poor girl in half right now.

So, I did. Not without a considerable bout of loin-girding though.

The end result is shown in the photo, although the rear bit is just resting there at a jaunty angle hence the variable gap. The plan now is to seal this up with a strip of aluminium, riveted in place with the gap maintained at 60mm. Once I come to finishing off the bodywork, I will put some release film under the aluminium and layup some gel and CSM on the inside to extend the bodywork. Using the film should get a pretty good finish on the outside (it’s shiny stuff that doesn’t stick to resin at all) without resorting to excessive application of elbow grease, a commodity in short supply around here.

I’m hoping that with the aluminium attached the bodywork will be a bit more robust; at the moment it’s rather floppy because the two sides are no longer attached at the rear. What’s more, I’m hoping that I’ll be able to remove it from the cage without any further surgery. That was, after all, the reason for making the cage backstays removable.

The conclusion of this is that I needn’t have worried. I had assumed that I was going to have tp weld a bar into the cage for the belts to go over, but it isn’t necessary, as you might be able to tell from the photo.

That’s good, so I could get on with the next thing. To be honest, I had intended the next thing to be getting the chassis off to the powder coaters as it’s essentially done now. However, Christmas has got in the way so I’ll have to leave that for a while. It’s no big deal really, as I can carry on doing lots of stuff, I just won’t be able to finally attach things to the chassis. However, I can do things in such a way that they’re a simple assembly job when I get everything back together.

One thing I did want to to before that, though, was to weld a couple of earthing points to the chassis. I ground all the nasty zinc off a couple of M8 bolt heads and welded them, in what I hope will be sensible locations, to the chassis. The one in the photo is in the engine compartment.

As I’m really thinking about the seat and controls here, the next thing was to attach the pedal box to the floor of the chassis, and make a cover for the master cylinders that I can park my size 12s on top of. The one in the photo is made out of some 2mm NS4 aluminium, as I wanted to be sure that it was fairly robust. Seems to do the job OK, at least at the moment.

Another thing that I’ve been thinking about for a while is whether I need to modify the pedals to make them a little further away from me. At first sight this isn’t absolutely necessary so I’ll leave well alone for the moment. I want to make sure that I do all the front end of the car in such a way that I can get access to all these things rather more easily than I can in the Fury. The complication on that car is that as the front of the car is the engine compartment it’s important that the pedal area is in a “fireproof” compartment, something that’s been useful in my car in the past, as you may remember. I did wonder, on the J15, about just leaving everything at the front open. However, if nothing else, it makes sense to insulate the passenger compartment just a a bit so that when it rains I don’t end up sitting in the backwash from the front tyres.

With the pedals done as far as I can at the moment, thoughts turned to the steering column. I’m planning on making this, as I did before, using 22mm CFS tubing running in 25mm Igus self-aligning bearings. To do that I made a couple of little sleeves to fit over the column tubing and fit snugly in the bearings. They’ve also got little  shoulders on them so that the thrust loads are transferred to the bearing balls. In the photo, the sleeve isn’t actually inside the bearing yet. I’ll clamp the sleeve to the column with a couple of grub screws.

I also added a spline to the bottom of the column that will connect to a standard Escort style universal joint, and I’ll also use a standard Escort lower column section. It’s amazing, the MkII Escort passed into history years ago but vast quantities of bits are still available for them because of all the use they still get as rally cars.

I then needed to work out where the column was going to go in the car. This is still subject to a bit of change but the photo shows where I ended up on this frosty Christmas Eve. As you can see I’m using tie-wraps and an advanced lignin/cellulose composite spacer to mount the bearings.

The one problem with this is that on full depression the brake pedal bashes into the lower steering column. This isn’t in a way that my foot also hits the column as at that point my foot can’t reach that far up with pedal. I can’t just raise the lower bearing as the angle of the UJ at the bottom of the upper column gets too acute and it starts binding up. I had been a bit concerned that the lower column was too close to the suspension rocker, hence that rocker being in the photo, but I needed have worried on that score.

So, I could:

1. Just leave it as it is as the brake pedal will probably never go that far anyway.
2. Grind a little bit off the corner of the brake pedal as I’ll never touch that bit anyway.
3. Think harder about a better position to get everything into.

Right now, I’ll think I’ll sleep on it. One thing I do want to do though, is to trial fit the front bodywork as that I can see where the steering wheel goes with respect to the bodywork.

Finally, an interesting observation is that the upper steering column is  much shorter than the equivalent one on the Fury, which also uses the same Escort lower column. This is clearly because the  driver is rather closer to the front of the car than in the Fury, hence the pedals being so close to the front suspension. No problem, just interesting…

It’s time to fettle the Fury for the next race and I decided to do a few minor things including changing the brake pads. Unfortunately, while doing that I discovered another crack in the chassis around the front right corner. Here’s a photo. As you can see, it’s all a bit grubby after most of a season around here.

So, I spent a while welding this up. I then finished off by changing the oil and filter. Hopefully, the car’s now ready for Mallory. I do keep wondering whether I ought to beefing up the front corners of the Spectre chassis after all this.

Back in Spectre land, things are progressing painfully slowly, although hopefully competently. Along the way I’ve been planning a few things and one of them relates to the steering column. I’m planning on making this from the same 22mm OD seamless tubing as I used for the Fury’s column. On the Fury I used some standard ball bearings which work fine but they’re rather heavy. For the Spectre I’ve bought some plastic pillow block bearings from Igus as in the photo. These are fantastically light and, according to Igus at least, should be well able to work as I’d want. One thing I’ll have to do, though, is to make something that will locate the column axially. I’ll probably do this by making a couple of collars that go around the column, located by grub screws, and run next to the bearing.

Back on the Spectre chassis, I welded the crotch strap mounts on. At first, I managed to do this in the wrong place. That is, they were fine but I couldn’t actually screw the harness bolt in. Doooh…. So, with the careful ministrations of Mr Angle Grinder I cut them off again and welded some new ones in in a slightly better position, as in the photo here.

Next thing up was making sure that the ARBs were going to work. Having worked out what was what with the suspension I can see that I’m certainly going to need an ARB at both ends of the car. As such, the first thing was to check that the bars would articulate properly. It took me some time to make sure that the ones on the Fury worked properly and making the Spectre ones properly right from the beginning makes sense.

As  on the Fury, I made some ARB mounts  out of some aluminium blocks. I used the lathe, as in the photo, to drill a hole between two such block so that the blocks could clamp the bar in position. I’ve been holding ARBs this way ever since I first saw  it on the mounts I used for the front ARB on the Westfield  I built ages and ages ago.

I think this is actually the first time I’ve used the 4-jaw chuck on the lathe. As you can see with this you aren’t limited to holding a round thing concentrically, although it takes ages to set up as you’d like.

This is the rear ARB, or at least the Caterham bar that I bought while ago masquerading as such, in position on one of the mounts so constructed.

I then spent literally ages working out exactly how to articulate the bars  and the suspension. I’ve reluctantly come to the view that I won’t be able to use the Caterham bar as it is. However, making my own in the same style isn’t too much of a problem. What I will do is do it the same way, with a separate arm welded onto the bar itself, rather than trying to bend it accurately.

After much faffing about, I finally welded actuation tabs to the rear upper and front lower wishbones onto which to connect the bars. The photo here is of the rear version.

As you can see, the bar is connected to the wishbone by a little turnbuckle made out of a couple of rod-ends and an aluminium rod. I’ll probably  have to make a bunch of these, assuming that a female and male pair of rod-ends won’t be long enough. As you can see, this photo has a damper in there, which is really just holding the suspension at full droop. I’ve been measuring the chassis with respect to bump and droop and it’s all rather odd in that the front suspension is set up in such a manner as to really need a longer damper. That’d be a pain in the bump so I’ll space the front lower damper mountings upwards. However it seems very odd. I’ve discussed it with Jeremy and he’s at a bit of a loss to explain it. It should be easily fixed though.

While thinking about dampers, Dave’s sent me a picture of the Solidworks model of the damper reservoir, as in the drawing here. Neat, isn’t it? Dave was talking about putting dry-breaks in to the hoses to this reservoir but I think that’s probably overkill.

At the rear of the car, the problem is clearing the driveshaft. At the front the problem is the track rods. However, I also managed to find a way to make that work, as in the next photo. This photo makes it look as if the ARB actuation arm is impossibly close to the track rod. However, it isn’t actually that tight. Experimention shows that it should be fine.

Finally, for this update at least, I’ve started sorting the engine as I want to actually make the mountings. In order to do that I need to make it the right size so I’ve fitted the billet sump as in the photo here. I’d forgotten, though, that the standard sump bolts are too long. Hence, for now it’s attached with the standard bolts and some spacers, which are actually M8 nuts. However, I need a long term solution to that. Also while I was sorting the sump, I drilled and tapped it to 1/8NPTF for an oil temperature sender.

Oddly, I seem to have two discs too, which I didn’t realise that Jeremy was going to supply. They’re not  the size that I’m going to use, and have already bought, but I might be able to press them into use as spares, I suppose.

I’ve already bought some Wilwood calipers from Rally Design for the front brakes, which are exactly the same as the ones I’ve got on the Fury. I mounted on temporarily on the upright as you can see in this photo; you can probably see that this disc is actually rather smaller than the ones I want to use. They do seem to be the same offset though.

One odd thing about these uprights is the hub. In the centre of a hub you usually have a flange that fits snugly into the centre of the wheel. In fact, it’s often too snug as those of you who’ve had to take wheels off using a large mallet will testify.

The photo on the right here is the original Fury front upright with the HiSpec brakes that I eventually consigned to the bin. You can see the pronounced centre to the hub here, something that’s absent from the Spectre hub above.

Conventional wisdom is that it’s this flange that takes the radial load of the wheel flailing about, with the wheel studs just providing some axial tension. That seems to make sense. However, the Spectre hubs are those that are supplied to Caterham just like that, and friends with Caterhams have said that this is indeed what they’re like. So, perhaps they’re going to be fine? I’ll have to think about this a bit more.

I could, of course, find some other hubs to use. I did find another company who list Caterham alloy hubs and the photos on their web-site shows hubs with a much more obvious central flange.

Hmmm. Any suggestions?

In the meantime, I’ve finished making the parts for the spherical bearing mountings in the rear wishbones. Here’s the complete set of parts which is precious tiny considering the size of the lumps of steel I started out with.  I test assembled one set, as below. At this point I did worry that the spherical bearings seem tiny, especially considering the humongous size of some of the rod-ends that Jeremy specifies. The bottom side of the front wishbone has a 5/8″ x 3/4″ rod end that connects it to  the chassis which is, in my experience, vastly  overrated for the application. The equivalent position on the Fury uses a 1/2″ x 5/8″ rod end without problem. Actually, I originally used a 1/2″ x 1/2″ but that did bend a bit under the braking loads.

So, I looked up, yet again, the spec for the spherical bearings. They are rated at an “Ultimate Static Radial Load” (that is, up and down in this application) of 19,875 lbs. I suspect that probably means lbf really. If so, call it 88kN. Clearly that’s fine for the static load which will be in the region of 300kg or about 3kN. However, the dynamic position is more complicated. I’m not an expert at this but from first principles if the unsprung weight is, say, 30kg, then 88kN would accelerate that mass through the full suspension travel of about 150mm in 10ms–completely ignoring minor issues of having to stop it again. As the usual suspension frequency is in the region of 1Hz that implies that the forces are rather lower than the 88kN mentioned about, by nearly two orders of magnitude. As such, that weeny spherical bearing should be OK.

Still seems tiny though.

I now need to actually put these into the wishbone. This will actually involve welding something to the wishbone, which is the point at which something could go horribly wrong. The photo on the right shows a set of these parts test assembled into the bearing housing on the wishbone. You should be able to see the circlip sitting in there which is retaining the spherical bearing in position.

The problem is that the bearing is a pretty snug fit in these sleeves that I’ve made. Actually, it’s very snug. If something distorts when I weld it in then I’ll never be able to get the bearing in and out, which is the whole reason I’ve gone to the faff of making all these bits. I guess if it all goes horribly wrong I can still go back to Plan A (or was it E?) and cut the whole thing off and weld a rod-end bush in so it isn’t the end of the world.

Watch this space…

Obviously this is slightly odd because the master cylinders are sort of where you would expect to put your heels. However, it’s only about 50mm above the ground so not too onerous. (If you look at an F1 car from the side it’s really hard figuring out where the driver’s legs are, they almost seem to be at head height.)

In fact, it’s not such a big change from the Fury as on that car the pedal area is already 25mm higher than the “seat” area anyway. So, this new box will be about 25mm higher than that, which shouldn’t be too bad.

When I get the pedals I want to look into making some sort of throttle linkage which has a slower actuation ratio at the beginning of the travel. One of the problems with driving the Fury in the wet is that the throttle is just too sensitive at small throttle openings. Once you’re beyond about 50% throttle that becomes irrelevant. To be honest you usually stamp on it at that point anyway. So, something that varies the ratio would seem to be sensible.

With this done (making the wild assumption that these can be made to fit nicely) I can start thinking about the steering. In fact, it should make life easier because the normal Spectre arrangment is for the steering column to thread between the pedals, as in the photo shown here. As you should be able to see, the steering column is coming out the pedal box area below the brake master cylinders.

In fact, I should be able to make the top of the pedal box area rather lower than it is in the usual Spectre/Riot builds. Mind you, I keep wondering how much panelling to put in at all at this end of the car, I can’t see that much is required at all. On front engined cars there’s lots of Blue Book regulations about keeping some sort of fireproof bulkhead between driver and engine. When the engine’s at the rear that isn’t an issue for things pedals and steering. That should all make this end of the car rather easier than it is usually. Mind you, I did wonder whether some sort of panelling would be useful just to make some sort of effort at keeping my feel dry(er) in the wet. If nothing else, access to the pedal box area will be a lot easier.

I’m planning on making the steering column in the same manner as I did for the Fury, using 22mm OD CFS tube. As for the bearings, I’m thinking about doing something slightly wacky and using Iglidur self-aligning bearings. These things, as shown in the drawing here, are entirely made out of engineering plastics. As such they’re light and are supposedly impervious to things like water and other grot. They’re not as out and out strong as something like a metal-to-metal bearing but it should be good enough for a steering column. This bearing here is rated at 6000N in the radial direction and 3000N in the axial direction and as such that should be OK. Mind you, I’m not sure how I retain the column in the axial direction; I’ll have to ask the suppliers.

If  nothing else, it’ll be fun trying…