A differential approach

One of the main parts of the running gear is in the shape of the rear differential from an E36 BMW, purchased from someone who races one. Equipped with a Quaife diff inside with 3.15 final drive ratio it matches up handsomely with the ratio's from the Tremec gearbox I will be running.

Overall in a rather grubby state I started by removing the rear cover which had previously had a 12mm thread added at the top as a larger breather. Replaced with a -6 fitting which will have a remote filter the other end. Blasted the cover, the original 2 bungs in the back cover have been replaced with -12 fittings to allow me to run an external oil cooler and 12v pump to keep it cool back there. Had looked at getting a Rogue Engineering finned rear cover, but the minimized ground clearance, import duties and overall cost of the item put me off, the money could be put to better use elsewhere. Have pressed in some billet/poly replacement bushes as the standard ones are rather baggy, have pressed them in backwards to allow me to have a mounting boss that will not foul the CV joint and will double as a rear wishbone mount at a later stage. Mounting bosses made from EN8D and tapped to M14

Wanted to get rid of the speed sensor from the rear cover too so took a few hours turning a billet blank to fill the cap, may get drilled and tapped to take a temperature sensor at some point. Nice snug fit and will hardly ever be seen, oh well.

Rest of the diff should be getting sent off to a local firm specialising in BMW Motorsport and will be getting stripped down to check for any wear. Then have the pinion and crown wheel shot peened to prevent any shock fracturing that may occur. Rebuilt checking the backlash finished up with new bearings and seals. Will cover this in another post

Click click.....

The 3D design of this has been going on for some time now, chassis books in hand. Measurements of components scribbled down and memorised for later recollection.

Spent a few hours after taking yet more measurements today organising where the top and bottom rails will lie in relation to the diff. Then where the pick up points for the rear wishbones will be to keep the desired geometry. Likewise the rails then need to locate the front wishbones whilst leaving ample clearance for the engine/bellhousing/gearbox arrangement. Then came the head scratcher when leaving enough room for the drive line components and then realised that the Kirkey seats I have will not fit between the tunnel and the main hoop of the roll bar. Time to rework the design and add a few more bends to the main back bone of the chassis. Now with a few more compound bends everything begins to tie to together. Added an uncommon style of door bar where the upper and lower have their adjoining faces milled out making for a much stronger joint that can be fully welded without breaking the structure of the tube itself.

So with this comes the numerous other thoughts that come with such a build, due to the orientation of the engine and with the exhaust and turbo configuration being on the off side of the vehicle I had known for a while I was going to have to make it left hand drive because of this reason and many other constraints. One of these being that the exhaust would run down the off side now passenger side of the vehicle, where leg room was not of such a high concern. This may however not even be possible still but that is a long way off yet.

Just a few of the things that float around my mind most of the time. Haven't got enough hours in the day to write down all my ideas and thoughts to details and implications I may incur.

Shutes

Stop, Pause, Lets RESTART

Think the best place for this is going to be in a blog,

Some reading this may already know me. Have had the car for years now, started life as a 1990 1.6 8v driver. Bought it when I was 14 and 'the project' has been going on and off for numerous years. Started off with building it to be my first car, that never happened, kept making the plans for it more and more bonkers. So was going to be air ride, wide wheels, smoothed engine bay, smoothed body work. With a supercharged 2L 8v engine.

Saw the light and started crewing on a drag racing team. They all have a lot to explain for most of my silly ideas, as do a few other people have something to answer for. This all lead me to rethinking my plans for my car.

So here I am, plans are now.

Full tubular chassis

Rear wheel drive

Longitudinal front/mid mounted 2L 16v turbo engine

Double wishbone pushrod suspension all round

Completely removable body

Road legal

Aim for the car is to have it road legal, but to be race legal as well. Want to have the possibility of sending it down the 1/4 mile, with the possibility to take it on the occasional track day, have a B road blast on a summers day, and maybe put it through its paces and see how quickly I can get it up a few hillclimbs.

Recently just moved workshops. Which although being a pain in the arse, was actually for the best and now in a large secluded barn with plenty of room and no noise restrictions. Had been progressing with the early stages of the build before the move, all the floor pan and monocoque were cut out, what is now the body was braced and the sills boxed back in, roof skin cut out.

Then moved on to the task of building a 4m x 1.8m RSJ chassis table for it to sit on and proceeded to mount the body to it and began offering up the mock up engine block.

Mocking up at the old workshop

Moving in to the new place.

Been gathering various different components over the last few months including

Quaife equipped E36 rear differential

ALT 2.0L engine block (aluminium instead of iron)

16v cylinder head

Holset HY35

Quicktime VW to T5 bellhousing

All the CDS for my chassis build

OZ Racing F3 centre lock wheels

Cast alloy front and rear uprights

Have many other parts that were intended for my previous plans which will be used in this build.

Have learnt the hard way in the past so have also been investing in decent tools. Armed myself with a home built tube bender built by a friend and a Baiileigh TN-250 for the chassis build, a Lincoln electric MIG, Colchester Bantam 1600 lathe and a Naerok milling machine. Have had a lot of help from like minded friends and contacts who have pointed me in the right direction. Finally going to build this car and do it right. Hardly like there is any going back now.

Bit of computer work, the chassis design by myself. The centre lock work done by my master machinist.

Always striving to make as much progress as possible, usually dependant on funds for parts. So don't expect a quick build. Look forward to hearing any feedback

Shutes