festy's Alfa Romeo Alfetta GTV

[Holden202T]

Nice set of nuts ?!?!

[festy]

4 months since I last updated this thread, and I haven't made much progress since then...
One thing I forgot to mention last time was that when I moved the car out of the garage, I blew another clutch m/c.
I assume I didn't hone it well enough when I put a kit through it last time, I vaguely recall my hone falling to pieces midway through and thinking "oh well, that will have to do"

So I spent ages trying to track down a new m/c at a half-reasonable price, and ended up ordering one from a big Alfa shop in the U.S.
Even paying $60 freight it still worked out cheaper than buying one locally

To get my money's worth out of the postage, I got them to add a few more things to the box that are either crazy expensive or just not available here.



One of the last suspension modifications I wanted to make (for now) was to get rid of the castor pillow bushes. The castor rod mounts to the body via a pair of big, soft rubber bushes - kind of like oversized shock absorber bushes.
They wear out fast, and that causes the castor to be all over the place depending on the load/direction etc.

Alfa came up with a solution for the SZ (which was based on the 75, which was based on the Alfetta) where they replaced the rubber pillow bushes with a ball joint from an Alfa 105 castor arm.
The 105s have a rubber bush at the wishbone end, but the Alfetta has a solid mount there so this modification makes the ride a bit harsher...

The new balljoint, and the rubber bushes it's replacing:


This isn't quite a bolt-on upgrade, the back of the balljoint has quite a large dome protruding, so the hole in the body has to be enlarged a fair bit. I made up some aluminium spacers to reduce the amount of metal I had to cut away, but there was still plenty of cutting required.
It's a 4mm steel plate, so out with the plasma cutter...


The ball joint thread is a bit longer than the mandrel it's replacing, and with the addition of the aluminium spacer it meant I lost a fair bit of adjustment range and possibly wouldn't be able to adjust the arm down short enough, so I cut about half an inch of the thread off.

The result:


This "simple" upgrade ended up taking me about 6 weeks to complete, the upper wishbones needed to be removed which was a nightmare of a job and I had to resort to a combination of fire and physical violence

I finally changed the thermo fan over to be ECU controlled, and generally tidied up a lot of the wiring.
...then ripped most of it out again because I needed to re-arrange a few things
Part of that was needing to move the center console panel back an inch or two, I couldn't reach the kill switch with the harness tightened and I thought I should probably fix that.

I picked up a new 3" harness, and a reclining passenger seat so I can still get access to behind the seats:


I found a pair of Konis for the rear, to match the fronts:


And discovered that the Alfa Giulietta had an electronic speedo and used the same transaxle as mine, using one of these in place of the speedo cable:


It's a reluctor type, but a zero crossing detector will take care of that.

I'm still slowly gathering turbo parts,
some 3" stainless tube and bends that will become a dump pipe:


and my brother donated some 3" intercooler piping he had left over from his car:



Next job is to learn how to do a DIY wheel alignment

[Holden202T]

nice work going on there!

[festy]

...discovered that the Alfa Giulietta had an electronic speedo and used the same transaxle as mine, using one of these in place of the speedo cable:


It's a reluctor type, but a zero crossing detector will take care of that.

Sounds almost too easy.... but things haven't gone quite as smooth as that

Around the time I got hold of that VSS, I drew up a reluctor amplifier circuit and sent the PCB artwork off to be manufactured.
When the boards turned up, I assembled one and tested it out with a frequency generator I cobbled together using an ebay ADS9850 module...

vss_PCB.jpg (70.59 KiB) Viewed 4190 times

but no joy

I checked the circuit, changed a couple of components for different values, but still nothing.
The next time I got a chance to work on it I quickly realised my mistake, the ADS9850 module produces a 0-5v sine wave, not much good for triggering a zero crossing detector

So then I set up my VSS in a cordless drill and tried that, but still couldn't get any signal out of the reluctor amplifier circuit. But then I noticed that I wasn't getting a signal *into* it either - spinning the VSS produced a little bit of noise but nothing like a normal reluctor pulse.

Nothing left but to open the sensor up and see if I can work out what's wrong. I wasn't sure what I'd find, but I certainly wasn't expecting this:

vss1.jpg (44.2 KiB) Viewed 4190 times

That doesn't look like a reluctor?

vss2.jpg (65.25 KiB) Viewed 4190 times

It's just a reed switch, no wonder there was no signal generated when I spun it in the drill
My first thought was to either replace the reed switch with a small hall effect switch scavanged from a brushless motor, or use it to switch a transistor to produce the necessary square wave signal, until it dawned on me that it will work just fine as it is.
Ground one side of the VSS and connect the other directly to the 808's VSS input, the 808 has an internal pull-up and the reed switch will produce a pretty damn square wave as it opens and closes.



So just for laughs, I thought I'd hook up a *real* reluctor sensor to my board - and guess what?
The damned thing has been working perfectly all along
(yellow = ABS sensor signal, blue = circuit's output signal)

reluctor_amp.jpg (52.01 KiB) Viewed 4190 times

(if anyone needs a reluctor to hall effect converter module, I've got a heap of boards spare... )

[vlad01]

lol!

wow! dodgy looking reluctor there

[festy]

But I did manage to get a couple of things progressed in between chasing my tail with the VSS...

I installed an oil cooler:

oil_cooler1.jpg (198.12 KiB) Viewed 4179 times

There wasn't room to fit a sandwich plate under the oil filter, so I mounted the filter remotely.
Unfortunately the only spot I could find ws where the battery tray was, so out with the plasma cutter for a light trim
One advantage of this is I can now use common Z79a filters that are about 1/3 the price of the standard ones.
(I still need to tidy this up a bit, even by my low standards it's not very neat)

remote_filter.jpg (107.18 KiB) Viewed 4179 times

This car was missing the lower grille/vent panels when I got it 15 years ago, and after giving up hope of finding a set in decent condition for a reasonable price I went looking for alternatives.
I saw supercheap sells grille mesh, but wasn't to fussed on the price so kept looking until I saw this:

gutter_mesh.jpg (55.91 KiB) Viewed 4179 times

I ordered a couple of lengths (some for a couple of troublesome downpipes, some for the car) and it appears to do the job. I might paint it red or black, but will wait to see how it looks with the grille and lights back in before I rush into anything

mesh.jpg (123.86 KiB) Viewed 4179 times

I'm waiting for some M3 button head bolts so I can replace the temporary 8G sheet metal screws holding it on at the moment. I could probably just use pop rivets, but I'm sure if I did that then I'd need to take them back off for some reason next week

[Holden202T]

good to see a result with board!

what you planning to seel them for ?

[Dylan]

I spent weeks looking for obe of these. The few I found were very expensive.
Unfortunately I have one now but you should be able to sell them.

[festy]

I think I could build them for about $30, I assume that's cheaper than what's currently available?

[Dylan]

Put them in a sexy little box with 2 plugs hanging out, reluctor in a hall out.
Use existing hall sensor wiring to power the unit its worth $50 EASY any day of the week.

My mate paid $150 for a Dakota digutal SGI5C. Great piece of gear. Converts both signals either way and pulse correction.