Pastelblau 520/6

[BertjeConti]

switch panel

Another job in progress right now is fitting a switch panel with some additional switches. It's a must have on a rally car.

My panel takes only 5 switches and is fairly small. All other switches on the dash keep their function, so its pure additional.
The ash tray goes out and makes place for the switch panel.

I've made a design on the computer and printed it mirrored on glossy photo paper, next the design is toner transferred to the aluminium switch panel by using a laminator.
Then the aluminium panel is etched, so the design is etched deep into the aluminium.
After that i've painted the design with red paint, sanded the panel after the paint dried out and etched it again for a short time to give the panel a dated look.

now some pics from the switch panel:

the aluminium panel and the mirrored design printed


ready for etching


result after etching


design painted red


panel over ash tray


switches installed


these functions are available on the panel:

select
connected to the display to select the different display modes

mix
this is my favorit, it's connected to the ecu and with it i can choose between two fuel and ignition tables:
eco tables are tuned for economic driving, the usual choise
fun tables are tuned in a way that i have some extra ignition advance and when lifting the throttle (very low map) the ignition retards a lot and extra fuel is injected, this will give nice popping sounds in the exhaust in overrun and shifting situations. This is normaly used on turbo charged engines to keep the turbo spinning while shifting.

pump
in the future i have plans for a second backup fuel pump, this switch engages it.

lights far
switch on the extra set driving lights, they are controlled by the high beam selector at the steering column.

lights map
switch for interior lights for navigator map reading (thats me)

[BertjeConti]

and the mail man delivered a present today:



some real vintage rally stickers which i won on ebay for a few dollar.

[uwbuurman]

Nice work, there, Rob!

[BertjeConti]

wiring

The switch panel is in, didn't take a picture yet, so thats for next time.

With the switch panel i've also upgraded my display, as you could have read in my megasquirt topic, with oil temperature and oil pressure read out.

Ofcourse al the new stuff needs wiring, the wiring loom to the oil sensors is routed via the right side of the engine, close to the exhaust. To protect these wires i've made a bracket that will hold the loom in a shielding firm away from the hot exhaust pipes.
The bracket mounts to the engine block on a spare M8 plug behind the engine mounts.

Here some pictures from the bracket and a mock up on a spare M20.





engine is upside down !!


For the extra driving lights a relay is needed, these lights are 100 Watt each. A thin wire runs from the switch to the fuse box, and is taped in the existing loom.
I mounted a relay socket to the fuse box that holds some fuses also. A main fuse and for each lamp a fuse, it's a relay socket like this one:


The extra driving lights will only go when high beam is switched on and the switch on the switch panel is on, in other words, they will go together with the high beams of the car.

To wire this socket i had to dismantle the fusebox again:



wires are in, relay works, fuses will go in when lamps are mounted.


another wiring job planned is shortening the spark plug cables, because they are now running a little wild through the engine bay.

[uwbuurman]

Nice job, Rob!

[BertjeConti]

Nice job, Rob!

Thanks Koos,

And because all this extra wiring isn't in the cars standard wiring diagram i've worked it out in separate sections and added them to the cars documentation map.

Now i know what i've done , but in a few years i won't, so a good documented project saves a lot of problems in the future.

extra set wiring diagrams:

Exyta driving lights


switch panel


Fusebox modifications for wiring in the Megasquirt.

[uwbuurman]

Cool!!!

[BertjeConti]

display update

So first the promised picture from the switch panel in the car, took it when dark, so it isn't the best shot:



The sparkplug cables were a little bit to long and ran a little wild through the engine bay, so i shortened them to make them a little more tidy:

Before:


After:





Today also finished the oil sensors wiring and bolted the pressure and temp sensor in. This was a good moment to do a oil and oilfilter change at the same time. Oil was more as 2 years in and did 6000 km.

here the bracket, wiring and sensors are in:


and now the wire shielding is also in, it stays far enough from the exhaust:






As you can see my engine block is well rust protected. i've never cleaned it up, and its old oil from a leaking valve cover gasket and plugs. That was a long time ago fixed, engine isn't leaking any oil at the moment.

So now it was time to test the upgraded display, exiting to see oil pressure from this engine for the first time.
Starting up the engine and saw that the oil pressure after a few seconds raised from almost 0 to 80psi, oil filter was new and empty so it took a few seconds to fill up with oil.



The second start up the pressure shoot right up to almost 80psi (5,5 Bar), and after a little warming up is was dropped to 25psi (1,7 Bar) at idle.

display with oil pressure and oil temp at idling, cold:


and warmed up a little:


The display has now a a lot of values to show, so i made a little video of it:



the upper two rows are fixed and show these 4 values (2 per row):

• speed
• fuel consumption (in l/100km or l/hr when stopped)
• oil pressure (psi)
• correcion ( shows fuel correction regulated for correct AFR)

the lower two rows give values selected with the "select" push switch, each time the switch is actuated the showed values are shifted one row up, 4 values are shown (again 2 per row):

• oil temp
• coolant temp
• manifolt air temp (=air intake temp)
• AFR (air to fuel ratio)
• manifolt air pressure (100 = 1 Bar)
• barometric pressure (100 = 1 Bar)
• rpm
• ignition advance
• idle (% opened idle valve)
• AFR (air to fuel ratio)
• battery voltage
• tps (% throttle opening)
• PW (inject time mS)
• o2 (voltage of o2 sensor)
• total consumed fuel (l)
• average fuel consumption ( l/100km )
• total trip (km)
• last trip (km)

holding down the "select" switch will reset the total trip and average fuel consumption

Thats it for now, next is buying some nice big driving lights

[uwbuurman]

Very nice work!

[Jeroen]

Nice tidy work, and great to see how many info is supplied on the display, impressive!

[bmw e12 e21]

Very nice work!
Ideal for a classic rally car.

[BertjeConti]

Calculations and the real world

These "OFFSET ROLL-CENTER SPACERS" just don't exist for early E24 or E12.

I don't have the tools to make them myself , and probably there aint enough room to place them and keep the 14" alloys. Another disadvantage is that these offset plates make the "SCRUBB-RADIUS" bigger, with the negative effect when taking corners, the inside of the car will raise more and the outside will drop more, because of the bigger SCRUBB RADIUS. And thats someting we do not want.

So I did some calculations what the effect of relocating the control arm mounts at the subframe would have. negative "Bump Steer" effects was my biggest concern.
These calculations weren't easy to do, because the suspension setup isn't as straight forward as most other cars, but after an evening calculating i had these results:

factory setup:
suspension travel 50mm in results in: add 0.7° neg camber and 0.12°toe out
suspension travel 50mm out results in: subtr 1.1° neg camber and 0.25°toe in

relocated control arms 15mm outwards setup:
suspension neutral: adds 1.3° neg camber
suspension travel 50mm in results in: add 0.8° neg camber and 0.14°toe out
suspension travel 50mm out results in: subtr 1.3° neg camber and 0.35°toe in

Conclusion: BMW E12 factory suspension setup has very little "BUMP STEER" effect, and changing the control arm mounts a little outwards doesn't change it much.

So this is my approach to give the car some negative camber and a little more track width.
The control arm mounts at the subframe will be moved 15mm outwards and 3mm upwards.

And here are the results of relocating the control arm mounts 15mm outward, the camber is measured now appox 1.5 ° neg

before:


after:



after:

[uwbuurman]

Nice!

[bmw e12 e21]

You see good the difference! I'm curious how she's going to drive.

[BertjeConti]

Mirrors

The mirrors on the car have bad scratched and misty mirrorglas, and because these are the first generation (-'79) electric mirrors the glass won't come off the easy known way. And spare mirror glass for these first generation mirrors are not available.
On top of it the righthand mirror was once broken off and glued back on, thats why the folding function isn't available anymore.

I had a spare 2nd generation ('79-) left mirror laying arround with nice glass and non functioning motors. After dismantling this mirror, i found a faulty diode and made a short, which caused the fuse too blow. After soldering in a new diode this mirror was OK.
These mirrors have only 1electric motor and a electric clutch, normal the motor drives left-right setting, and when the clutch is engaged this same motor drives the up-down setting. Clever design, and "Made in Holland".

new diode soldered in:


After a very short search i got a spare righthand mirror from a forummember, thanks Ite. So now i've 2 spare mirrors with both neat mirrorglass and both 2nd generation which means easy glass exchange.

The housings of these mirrors weren't black anymore and looked very weathered, so i painted them with a spray can plastic paint.





and put them back together:





But why red and not black ??

I'm planning te give my pastellblaue E12 some red details to make it a little more "rally" style.

Hopefully these mirrors are on the car next weekend.