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Slow updates with it being silly season for farming, so nothing really new picture wise, just been working on refining the mapping after switching over from alpha-n as we were struggling with throttle response (inlet tract is longer than I'd like) - and investigating a few sensor errors on the crank/cam sensors - work on masking the windows helped out but I suspect we might have a duff cam sensor, so awaiting a replacement unit.
Dash back out to tidy/clip up all the connectors and drill holes for the dash control button and launch control dial too, which means I've got to make connectors for all the switches now everything is working, so they can be unplugged easily rather than having 4-7 pins per switch to keep track of.
Hah, yes, he used to love his time down at the workshop, he was rather attracted to shiny parts though, every time you turned around your socket and spanners would have gone missing - they'd usually turn up outside in a pile with a grinning dog sat by them, like a dragon with a gold shortage.
Unfortunately he's since passed away, so he didn't get a ride
Well, been a little while since an update, not a lot done really, we were waiting for the fiddle brake frame and few other brackets and mounts to come back from the platers, so I decided to update the dash firmware and change the screens around, that didn't go well:
Anyway, after a chat reverted to a slightly older version of the firmware that worked but still had some improvements over the old version we had on the dash. Great. Then tried uploading the new config....
Yeah, that didn't go great either, maybe I should have left it alone whilst it was working...anyway, gave up on that for the moment (it's being sorted out), and bolted the shiny bits on that came back from plating, tweaked a few things for easier servicing such as having the power cable on bulkhead attachments rather than straight through - made out of the same polyurethane as the exhaust mounts in the other thread, as a bit of flex reduces fatigue in the cable and it's pretty resistant to chemicals and heat.
Also in the servicing improvements, we tweaked the corners on the fan cowlings and ducting so now they can come straight out as a since unit instead of splitting them, same for some of the rear heatshielding over the exhaust and water pipes.
Just tidying work really.
Then decided that was all far too sensible. You know how I said we always have to make things three times? I lied.
Front suspension/uprights version 4 is in progress, ditching the link pin and sliding setup that it inherited from Volkswagen, and switching over to an upright using some large sealed spherical bearings instead - that allows us a much wider area of camber change without binding, much less friction, and because the original link pin requires some play to work correctly, we can get rid of that too, so we cut down massively on play/slop in the front suspension.
It'll also allow me to ditch some of the poor geometery around the scrub radius and castor gain in the original VW setup:
This won't be the actual upright, just a quick model to tweak clearances and geometery for the moment, design work on the proper one is in the 'stare at the front end and scratch head' stage at the minute. It's a bit more complicated than it looks as the current clearances between the front coilover and arms is tiny, and they already use 99% of the travel available on their bearings, and the steering tie rod currently clears the frame at full droop by about half a ciggerette paper.
And we've moved the spindle down 3" on the new uprights so it's screwed all the mounting points up.
Oh, and of course, being spherical bearings instead of a circular kingpin, the steering angles are limited, even with inserts to let the joints move further....so they need a bit more work yet. Good fun.
It may yet be a 9" angle grinder to the front bulkhead...
Well, no shiny pictures again, sorry - slow work on the uprights, everything at the front is pretty critical in terms of spacing - we're already using every millimetre of travel on every joint, etc, we have and things are rather tight, so we're slowly iterating the new front hubs with bits of scrap to see just what we can get away with - it's very tight for getting enough steering lock - we end up with the joints actually over centre at full lock at the minute.
Anyway it's getting closer, then once we have something that's close need to work back and see how far from the model we are geometry wise and tweak things again.
It's going to take a while so that's gone on the back burner as a slow project and back to the usual build-up stuff like new canister mounts for the dampers, spanner checks, the driveshafts and CV joints are built up and on, I just need to strip the rear dampers and drain the oil now so I can make some valving changes and machine a new droop spacer to go on the rod - that's tommorows work, along with priming everything and turn the key....
Well, after I finish drilling holes in a flywheel anyway...
So, we've had it running, why isn't it outside yet?
Well, been hunting down some issues with the engine for mapping (turned out to be an intermittent air leak on gasket but took ages to hunt it down), and we're still having some problems with the dash that are being worked on atm.
And, whilst we were putting the front suspension back together....well, the front fell off. I know it's not supposed to fall off but....
Anyway, the old front arms were a little worn so we tacked together a new set, and decided to narrow the front beam tubes slight as the tyres rub in full lock if we have the wider options on....which lead to tacking up new arms to suit....and then we decided if we're doing all that, it might be time to ditch the VW uprights as well.
For those unfamiliar with the old Beetles, the front uprights are a link and kingpin setup - basically there's a big Kingpin vertically that sits inside needle bearings, which allows the steering to happen. Then on the end of the front arms, two pins stick out horizontally into some bronze bushes for the upright to pivot on when the suspension cycles up and down.
Now, that's a relatively robust setup, as it's basically just some huge hardened steel pins taking the loads, but it also means you have to deliberately leave the pins loose to allow the suspension to cycle, which means even in perfect condition there's always some slop in the system, and also as the loads change and things flex, the friction in the front suspension jumps up and down as the bronze bushes get pinched and wear.
The steering effort also changes massively as the kingpin runs against a hardened steel washer - so the friction there changes massively with load - if you look back through the old photo's you'll see I replaced it with a bronze+acetal thrust washer when I rebuilt them the last time to help it out.
Anyway, after a lot of trial and effort get get the required angles and clearances, we've managed to get just about get enough room to switch out to a new upright using a pair of spherical bearings instead, which means everything can be bolted up tight, camber can be adjusted easily by just shimming behind the upright, and friction should be a bit more consistant as all the loads are taken through the bearing surfaces with no pinching/rocking effects like the old link pins had.
Whilst we were at it I took the opportunity to correct some of the VW front geometery at the same time - so we have less castor gain, less mechanical trail for the same castor angles, and I've corrected a lot of the scrub offset issues the Kingpin setup had
We've also shifted the axle down to the lower arm point - this lifts the arms further out of the muck if running in deep, soft mud/peat, etc, and also means we can have a bit more travel up front (as we were only limited by arm angles in droop)
Anyway, just waiting for the parts back from the laser cutters and it can go together:
....just when you thought it was nearly ready
Oh, yes, instead of altering the beam to narrow it, the whole lot just met Mr. Angle Grinder instead. Whoops. Lets us ditch some of the old plates up front from the original car build and save a few kilos.
Yes, I've just being trying to get all the parts for this and some customer car bits out for the laser cutters so it's all back before christmas, then it can all go back together and off for mapping
And if need be, the old front end can get tacked back on just for mapping if we have to.
Been chasing down an intermittent, annoying issue for the past month or so where the car would only fire up 50 percent of the time - and sometimes would cut out for no apparent reason, eventually traced it to a dicky cam sensor and some split wiring on the only original part of the cars loom we kept - the coil connectors, doh. Anyway, after taking allsorts off finally found them, repaired 'em and turned the key, boring video but god was I happy!
Sound is a bit funky as the phone clips hard on the audio that close and the exhaust's blowing from the elbow there 'cause it just got slapped on.
Well, just as we thought we were sorted - the car ran fine when fired up - the intermittent starting reared it's head again, been tracking that down again over a couple of weekends - traced it down to what we thought was the alternator or the ballast, so I pulled the loom apart and added a larger ballast to the field coil, no difference, bought a new alternator - no difference. Take alternator off, starts fine.
Much head scratching.
Turns out the alternators we were getting from the local supplier (an electrical specialist, not just a factors) - were basically noisy as hell when they were trying to get to the right voltage at low rpms (i,e - startup only) - a cap in the line doesn't fix it, some shielding might but we've just sacked it off and got a different type of alternator instead, need to alter things to get that to fit properly again now....
It never rains, it pours!
On the upside, I was rebuilding some other dampers* so I rebuilt/revalved the rears on ours to suit the new arms and bled them, so that's one more job off the list and ready to go - although I have just acquired some new go faster parts to machine and fit...
They're Top Secret Go Faster Parts™ - in case you can't tell
10 points if you know what they are...
*Well I say other dampers, but they looked more like scrap....I might drop some pictures in here later if anyone wants to see oily shafts....
It's all very well getting shiny adjustable parts for your dampers but then you have to spend hours modelling the damned things - nearly there, housings next.
These are high and low speed compression adjusters for the dampers, that hopefully with a bit of work on my side will be adaptable enough to use both on the small fronts and large rear dampers...hopefully.
Seems a shame to go back to the old front end when the new ones were finished mocked up and are mid fabrication for the actual ones, but screw it, back to the old we go - it can have an upgrade after the dyno instead...
Thought I'd let you at least hear a couple of thousand revs:
Throttle response is a little slow currently, but I think it's mainly down to the idle mapping running a bit lean - it stumbles a touch when you first touch the throttle from 1k.
I need to check my changes to the cold start settings I've been making today when she cools off enough, and then I can hopefully richen the idle area and lean the main map out a bit to perk it up.
Got the coils/injectors back up and running in sequential mode as I turned everything to dumb group fire when diagnosing, so timed in the cam trigger wheel and I've done a bit of work on the low-load transients so it picks up nice and cleanly everywhere bar around idle.
Need to get it to the dyno then to get it spot on - it's deliberately tuned on the rich side with a bit of timing pulled at the minute to protect it until then - but basically everything else is setup in the map ready to go.
I'm not sure it'll have any exhaust packing left by then though, it's covered the workshop in it...I got a bit more enthusiastic with the throttle later on as I got it a bit crisper
Timed it back in again today because, as I thought earlier, it was off a bit from the previous issues....times the above video by two for how rude it sounds now!
I got the vast majority of the low down fuelling and timing tweaked a lot closer too as the cold start settings yesterday turned out to be nigh-on perfect - so now there's no more stumbling - it certainly picks up on the throttle now!
I know, I said I wouldn't post another one, the next one would be it on it's wheels outside, but I just wanted to finish things off before we took the engine out for a spanner check, oil change, loctite session, etc.....plus, I found this shiny red button....well, you've got to press a shiny red button - it's the rules.
And look, I even treated you to a different camera angle for the first 20 seconds for a change, see, now it's boring video from a different angle - so that's fine.
Colour coded driveshafts?
Yes, not content with being the fashion leaders with colour-coded brakepads, we're now forging the way for the Next Hot Thing™ of 2019 - colour coded driveshafts, you saw them here first:
And a quick picture to show how well the combination of the Spiralox circlips and the counterbored CV stars work - there's no way in hell it's knocking those circlips off!