Two car Tim

There’s quite a lot of good photos around of the race at Snetterton. The one shown here was taken by Derek Jones’ Dad at Russell chicane. That’s Tony just behind me, thankfully.

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.