Rear Half of Roll Cage Fitted

The previously made template was used to accurately mark out where the holes needed to be cut for the rear bracing tubes.  A hole saw and a curved file were used for this.

What I hadn't appreciated was that these bracing tubes were at a slight angle.  Meaning that the holes had to be widened to get the ends through, before the rear half of the cage could be lowered in to place.  Covers will need to be made for these.  Probably out of aluminium sheet sprayed white.

The feet were then bolted on to the bracing tubes and holes drilled in the rear of the chassis to accommodate the fixing bolts.  All in all not too bad a fit, the fabrication tolerances probably within a few millimetres.

Luckily the off-side bracing tube clears the fuel filler by about 10mm and also the filler pipe below.  Phew!  That was a close call.

After fitting I tried to get in the boot.  Oh dear, we have a problem.  Looks like the boot on the Avon Mk2 bodywork will only open to about 45 degrees with the roll cage fitted.  Never mind, access is still pretty good.

Next on to the front half of the roll cage...

Delivery of Full Race Cage

Yesterday my full race cage arrived.  This was delivered on a pallet direct from the manufacturers Caged Laser Engerineering.  It is comprised of a braced roll over bar with the main part of the cage bolting to this and the side chassis rails.

It is very substantial and quite heavy.  Much tougher than the chassis by the looks of it.  Which I suppose is reassuring and whole point of fitting the cage.  The quality is very good and it comes complete with a fixing kit.  We'll see how straightforward it is to install.

Holes need to be cut in the top of the rear tub to allow the diagonal braces to pass through.  The feet are bolted on after passing through the braces through the holes.  This helps keep the holes as small as possible.

I've made a cardboard template to establish the location of the holes.

I'll use this template to transfer the dimensions across to the top  of the rear tub.  I am praying that fuel filler is not in the way and does not need to be moved.  Once I've got the old roll over bar off, and the template offered up, I'll know for sure.

0-60 (well 0-62 actually) in 4.66s!

Finally got round to trying out the acceleration timing feature on my digital dash.  It has three modes 0-62mph (0-100km/h), 62-0mph and 0-400m (1/4 mile).  I had a few runs using the 0-62mph setting.  My best time was  4.66 seconds.

I think technique and gearing are big factors in setting a good time.  After a few practice runs I was getting better at getting the power down without lighting up the rear tyres.  In second gear the engine is getting near the red line at 62mph, but it just makes it.  I think with some more practice I could knock a bit more off this time.  With a better road surface, i.e. a track/airfield, as opposed to my slightly bumpy deserted country lane, further fractions of second could be knocked off.

Anyway, just over 4.5 seconds to 62mph is very satisfying, especially for a car that you've built yourself, and a level of performance equaling cars many times more expensive.

Must get round to trying the other two timing features.

Stone Guards

Like most (all) Sevens, my Tiger Avon was starting to get a lot of stone chip damage on the fronts of the rear arches.  A lot of this comes from stones that are thrown up by the front wheels.  Some people fit mud-flaps to the front cycle wings, but I don't really like the look of these - too much like a rally car.

I decided to follow the crowd and add stone guards to the front of the rear wings.  These also help prevent damage when getting in/out of the car.  To make these I used cardboard templates to transfer the dimensions to the 1mm aluminium sheet.  The shapes were then cut out using a guillotine (lovely straight edges that can't be achieved with tin snips or a jigsaw).

The aluminium was then shaped to the curvature of the arches by gently bending around a cylindrical plastic kitchen bin.  Holes were drilled for the rivets and then 2 or 3 coats of spray etch primer were added.

Thinking that most paints would chip off I decided to try using an automotive stone chip paint.  Black Hycote Stone Guard spray paint to be exact.  One 400ml can was enough to do about 2-3 coats.  The formula of this paint contains particles of rubber.

Once dry the stone guards were riveted in place using black head pop rivets.  I've been out for a spirited drive down some country lanes and the paint seems to be holding up very well - no chips yet.  Let's see how they handle some high speed motorway driving.

Brands Hatch Novice Track Evening

Tonight I've been to a novice track evening at Brands Hatch Indy race circuit.  I was very lucky with the weather and had a fantastic time putting the car (and myself) through its paces.

Seeing the photos has made me realise how inadequate the roll-bar is.  The next day I placed an order with Tiger for the full race cage.  Hopefully, this will be delivered and fitted soon.