Indicative gauges are exhausting

Following on from last time, I have now completed the wiring to the front end, with indicators, side repeaters and headlights now all wired up and working.

When browsing forums, I found someone who was selling a MAP-ECU 2 – the next version of the MAP-ECU which I already have installed (the little box of tricks that allows removal of the MAF sensor) – the newer model adds a few new features – ignition timing control, two switchable maps, electronic boost control, air/fuel ratio adjustment, fuel cut removal, speed cut removal, and launch control.

I paired this with a wideband O2 sensor/controller, which provides a very accurate air/fuel ratio to the MAP-ECU2, as well as a simulated narrowband output to the stock ECU.

PLX SM-AFR PLX SM-AFR

A standard narrowband O2 sensor as fitted to most vehicles operates by switching the output between 0v and 1v when the air/fuel ratio (AFR) goes either side of the stoichiometric point – the point at where all fuel is evenly burned with all of the available air – with petrol this is an AFR of 14.7, or lambda 1.00

The narrowband O2 sensor is used by the ECU to adjust the amount of fuel – an input value of 0v means “add more fuel” and an input value of 1v is “less fuel” – under normal use, the standard ECU will adjust the fuelling to ensure that the input voltage from the O2 sensor is rapidly fluctuating between 0v and 1v – this keeps the engine around lambda 1.00

This is shown by the following graph (graphs taken from the PLX website)

AFR Narrowband Output

The wideband O2 sensor gives a voltage output which is directly related to the AFR, typically from 0v to 5v. The PLX SM-AFR I have provides a linear output and can show the AFR from 10:1 to 20:1 (lambda 0.68 to 1.36), as demonstrated by the following graph (again, taken from the PLX website)

AFR Wideband Output (PLX SM-AFR)

When running under load, you may not want an AFR of 14.7 – you may want to run richer (more fuel), say at an AFR of 12 – with a narrowband O2 sensor, you have no way of telling what your AFR is, only that it’s “rich” or “lean”. With the wideband, I can monitor this via the MAP-ECU2, and adjust the fuelling accordingly to reach that target.

The MAP-ECU2 came from another VR-4, and the configuration that’s on it is much better than the one that came on the original MAP-ECU I had (which also came from a VR-4) – the new one idles even better, and the lag that I had when pressing the throttle has disappeared. Even just this change is worth the money spent on it, as it puts it a lot closer to what’s needed, which will hopefully reduce the need for an immediate expensive tuning session!

In addition to this, I received a nice package from ETB Instruments consisting of a 52mm fuel gauge, a 52mm temperature gauge, an 80mm electronic programmable speedometer and an 80mm tachometer.

I am fitting these to a glove box lid, so I started by marking up and drilling out the necessary mounting holes:

Dial panel

It was then time to fit the dials, and wire them up to a connector plug to allow easy removal from the rest of the wiring loom.

ETB Instruments ETB Instruments

The new speedometer is programmable so it can be used with a wide variety of speed sensors and can be programmed to suit your wheel/tyres, diff and gearbox – and any changes to any of these the speedometer can be reprogrammed very easily – if I had a mechanical speedometer, I’d need to send it off for recalibration if I ever made any changes.

It also provides the following features:
2 trip counters
0-xxmph time (comes as default set as 0-60mph)
1/4 mile time
Max speed recall
In built indicator lamps

I also fitted a 3-spoke Momo steering wheel from an Evo 6, which is slightly smaller than the standard wheel from the VR-4, and placed the dials in place (but the glove box lid is not secured to the dash properly yet)

ETB Instruments

Whilst I was fiddling with wiring and electronics, my dad was concentrating on welding, and we now have the passenger side rear suspension mount and floor completed, as well as the exhausts now properly mounted on cotton reel mounts, rather than suspended from bits of electrical wire.

IMG_5559 IMG_5558

Flipping front end

I start off this time with some braking news…

This just in: Capri 2.8 vented discs fitted!

Capri 2.8 vented discs

Next up, a one-piece fibreglass front from Team de Ville. A small amount of trimming was required to make it fit, as it comes supplied with the lips down the back edge of the wings which tuck around the A pillar behind the front of the doors. As I wanted to be able to flip this open without needing to have the doors open, these lips were removed.

Fibreglass flip front Fibreglass flip front

And then, with grill, headlights and surrounds fitted. Just left to fit the bumper, and indicators, and then do the wiring.

Fibreglass flip front

It’s finally looking more like a car!!

Lights, Camera, Picture

More wiring! More headaches!

Other than general tidying and removal of extra length, the main thing that needs sorting now wiring wise is for about the only electrical systems left on the vehicle – lights, horn and wiper!

So – onto those then! Wiring for horn + front lights was identified, tidied, routed, loomed and affixed:

Front light wiring

With a nice connector plug ready to make removal of the fibreglass flip front (which has been ordered, awaiting delivery) as simple as possible.

And the rear lights were dug out of storage, bulbs checked and replaced where necessary, and wired up, including tidying up and re-looming the run of wires to the rear:

Rear lights

An Automation Simulation

A couple of months ago, I came across an interesting game which is still very early in development, that rather piqued my curiosity.

The game is – the premise is that you start off post-war (1946) as a budding car designer/maker, and you need to design and build cars, progressing through time, making new models, utilising new technology and generally trying to make as much money as possible.

Whilst this sounds fairly cool, the “tycoon” part of the game isn’t made yet. When I first saw it, it was basically an engine creator – allowing you to make Inline 4, Inline 6, and V8 (crossplane & flatplane) engines, both naturally aspirated and turbo. Unfortunately, no V6 engines yet… (can you see where this might be going…)

A recently released update adds a number of features to the car designer, mostly around wheel/tyre, brakes and suspension, as well as adding a number of new performance statistics which are updated based on the options you choose.

So, what better than to get a few ideas on performance on something that’s rather similar to what I’m actually building!

So, first off, I present the 8A13TT engine – the 6A13TT engine has a 81mm bore and 80.8mm stroke giving 2498cc – my 8 cylinder engine is also 2498cc, with a 73.6mm bore and 73.4mm stroke to achieve it (following the V6’s 0.2mm difference between bore and stroke)

The goal is ~276bhp and ~260lb-ft torque, so let’s spend a few minutes making it:

automation-engine-1

Not too bad 🙂 On the 6A13TT, the peak torque comes in a little earlier, and holds a bit higher towards the red-line – but close enough for now!

So, onto the next part, which is designing a vehicle for it to go into. There’s a number of body styles available, but nothing that will allow me to make the unique shape of the Anglia, so I’ve settled for something that looks a little more like a Mk2 Escort.

Whilst the body shape is important in Automation to the aerodynamics, and subsequently the performance, neither an Escort or an Anglia are the most aerodynamic of cars out there, so we’ll take the estimations as just that, and instead concentrate on the meat that I’m interested in – that being suspension and tyres.

For this, I’ve chosen MacPherson strut for the front end, to mimic the Escort setup I’m using, and I’ve selected the “solid axle coil” to represent the rear – my De-Dion acts most like a solid axle in terms of bounce and roll, it just doesn’t have the heavy diff in the middle.

You can specify camber (in degrees), spring stiffness (in Newtons per meter, 25000 N/m = ~140 lbs/in for those of you who work in old money), damper rate (in Newton-seconds per meter), and anti-roll bar stiffness (in Nm/rad, Newton-meters per radian)

I’ve currently got 140lb springs on the rear, and I have put an estimate of 200lb springs on the front, based on what I’ve seen people using on other vehicles with heavier engines up front – so these have been plugged into Automation.

These suspension settings will give you results for roll, weight transfer, body bump, and when matched with wheels/tyres (where you can specify wheel diameter, tyre size and compound) will also affect acceleration and cornering.

So – by putting in some known values from what I will be using (13″ wheels, 185/60 tyres), along with the engine/gearbox settings (5 gears, top theoretical speed based on gearing of ~160mph) and an overall weight (I’ve chosen 1000kg) and weight distribution (roughly 50/50) – my dad’s 4WD Anglia weighs 980kg and has near perfect 50/50 weight distribution, so a good baseline.

Putting all of that together gives the following results:

automation-chassis-1

Some key points without enlarging the image:
0-62mph: 6.4 seconds
1/4 mile: 14.3 seconds @ 109mph

There’s a number of graphs, but I’ve put up an interesting one in the image – the Acceleration graph. The blue line shows that it calculates that in the first 3 gears, I will have too much power for the tyres to cope with. It’s not until I hit 4th gear at approximately 7 seconds that I’ll have enough grip to utilise the full power of the engine.

Obviously, here’s where everyone jumps in and tells me that of course, the engine is too powerful for the car, and that I’m doing it all wrong.

However, where’s the fun in that? 🙂

Front suspension polybushing

Just a quick update this time round! Have been doing some work on the front suspension, replacing the existing rubber bushes on the track control arms with new polyurethane one. The old bushes had so much play in them, the front suspension geometry was all over the place. With the new bushes, the front end has no excess play, and the tracking can be set accordingly.

Also spent some more time on wiring – still a fair bit to tidy up, and every little helps, even if it doesn’t look like there’s been any progress!

A lesson on Blow Off Valves

Last time, I managed to get as far as hooking up a couple of hoses from the chargecooler to the bulkhead.

So the task this time was to complete the chargecooler circuit, which involved running pipework to the rear of the car, through the boot floor and to the radiator box, which still needed a bit more to easily hook up the pipes.

Chargecooler pipework

Forgot to take any images, but the chargecooler system is now completely plumbed up, including an old coolant header tank as a reservoir, and the pump is hooked up to the trigger for the fuel pump, so is running whenever the ignition is on. An adjustable temperature-activated switch is still to be installed, which will switch the fan on when the coolant temperature in the chargecooler circuit gets to a specific temperature – which is yet to be decided!

Having had a bit of temporary pipe on the inlet, which had to be bunged up with an old injector, it was time to change this to a proper bit of pipe, with the correct outlets on it – such as for a blow-off valve (BOV – also known as a dump valve, or diverter valve)

The job of the BOV is to relieve excess pressure in the intake when the throttle is closed.

When you accelerate a turbo’d engine, the exhaust gasses drive the turbine on the turbo, which in turn drives the compressor on the turbo, which takes air at atmospheric pressure, and compresses it to a higher pressure – the standard TD-03 turbos on the 6A13TT will compress the air to about 10 PSI above atmospheric pressure (which is 14.5 PSI). Once compressed, there are more oxygen molecules in a given volume, and this allows more fuel to be introduced, which creates a bigger bang in the engine, and therefore more power (and more exhaust gasses) – the process repeats over and over.

With the throttle body open, this compressed air will get forced into the cylinders in the engine. When you stop accelerating, you close the throttle body, and there is now nowhere for this compressed air to go. The turbo continues spinning for a small amount of time after you stop accelerating, which continues to compress the incoming air – trying to add to the compressed air already in the inlet pipework between the turbo and the throttle body.

If there were no BOV, then this compressed air would try to equalise pressure by the easiest possible route – which would be to try to go back out through the compressor of the turbo – this can cause the compressor of the turbo to be attempting to compress the air, whilst the already compressed air is trying to come back the other way – causing the compressor wheel (and, because they are linked, the turbine wheel) to stop turning, or even attempt to turn the opposite way (fighting against the exhaust gasses still trying to turn the turbine the correct way) – this can cause a “fluttering” noise. This is also known as compressor surge.

You can hear it a bit in my previous videos, but the following video also shows it off well:

To prevent this, the BOV is installed in the inlet pipework after the turbo, and before the throttle body. This is a large valve, operated by a diaphragm, which has a spring inside to hold it closed, as well as a vacuum/pressure pipe which is attached to the manifold (after the throttle body) – when the turbo is producing a positive pressure in the intake manifold, this pressure also assists in keeping the BOV closed by pushing against the diaphragm. Spring + compressed air pressure on one side of the diaphragm is a larger force than the compressed air pressure in the intake pipework.

When you close the throttle body, the intake manifold then goes into a vacuum, which pulls against the diaphragm – this vacuum, combined with the positive pressure of the intake pipework, allows the valve to open – giving the compressed air in the intake pipework an easy route to escape, without going back through the turbo compressor wheel.

On most production cars, this is routed back into the intake *before* the turbo – a recirculating valve. Especially where a MAF (Mass Airflow Sensor) is used, where the air has already been accounted for by the engine ECU. It is less of an issue where a MAP (Manifold Absolute Pressure) sensor is in use, because this air has not been accounted for yet by the ECU.

The Anglia has no pipework before the turbos to route this air to – therefore the BOV used is a Vent To Atmosphere (VTA) one. A VTA BOV is what gives the “pssssstthhhh” noise that you associate with a turbo car.

Intake pipework completed

(the picture was taken before I’d attached the small blue vacuum pipe to the BOV – this is what attaches to the manifold)

With the inlet pipework and BOV now correctly hooked up – there is no loss of pressure in the inlet any more, and a small touch of the throttle causes the boost to climb quite quickly! It’ll be fun to drive…!

You gotta speed it up, and then you gotta slow it down

I began last time to fit the brakes to the car, and the most of the work on the car this time round was in completing the braking system.

This involved running 2x lines from the master cylinder to the servos in the boot, and from the servos, out to each of the 4 wheels.

IMG_5024 IMG_5032

Taking cues from modern vehicles, we are installing dual circuits, splitting the circuits diagonally across the car.

One circuit is Left Front/Right Rear, the other is Right Front/Left Rear. By doing this, should there be an issue with one circuit, the other circuit should still be able to provide braking force, and by diagonally splitting the circuits, the braking is more balanced during these situations.

As I am using a combination of Escort calipers on the front, and 200SX calipers on the rear, I can’t buy a flexible brake hose kit off the shelf, so took another trip to Hosequip where they made up some custom braided pipes with our choice of ends to suit our needs.

IMG_5034 IMG_5036

The chargecooler was also put into place, and have begun to plumb it in.

IMG_5027 IMG_5028

We also spent some time moving my dad’s ramp from one side of the garage to the other – with the new roof we fitted last year, this now allows us to get the car much higher off the ground – and can now stand underneath it, rather than having to crawl under it! This will help when we do the remaining welding under the car which will need to be done prior to thinking about putting it on the road.

The credit card gets a hammering

This is by far the most expensive update I’ve put up throughout the history of this project!

The first item on the credit card statement is a proper fuel tank. With the changes to the axle and the dual exhausts, the standard fuel tank was removed a while back. Additionally, I had a couple of brand new in-tank fuel pumps, so it seemed silly to not utilise them. Plus, with the car starting and running now, it seemed a sensible time to replace the bucket, and we can now keep it fuelled up so it’s easier for my dad to move it around should he need to.

I contacted Alloy Racing Fabrications who were able to make me a nice shiny alloy tank to my exact specifications.

New fuel tank from Alloy Racing Fabrications New fuel tank from Alloy Racing Fabrications

The pump housing is the same as was used in the bucket, but the pump itself has been replaced with an uprated ProDrive pump as fitted to the ProDrive Imprezas – will definitely supply plenty of fuel to the engine.

The next line on my credit card bill is for brakes – a new set of M16 calipers to bolt up to the Escort front struts. We also got hold of a couple more 13″ tyres and fitted them to the remaining 4-spoke alloys, so it’s now got a full set of matching wheels.

New M16 calipers Full set of 4-spoke alloys

The VR4 engine usually has an air-air intercooler to cool the compressed air coming from the turbos before it goes into the intake. This is placed at the front of the car and the ambient air moving over surface of the intercooler cools down the warmer air passing over the internals of the intercooler.

Whilst I had never planned to fit an intercooler due to space constraints, I decided on instead fitting an air-water chargecooler.

The chargecooler works with a similar process to the standard engine cooling – a liquid coolant is pumped through the chargecooler, and then passes through a radiator, which removes the heat from the water.

A chargecooler allows fitment in a tighter space than an air-air intercooler, and doesn’t require the lengths of large-diameter air pipework between the turbo and the inlet. All it requires is a couple of much smaller diameter coolant pipes.

There are a number of styles of chargecoolers available, but I decided on a barrel-style, which will sit in the current inlet tract, replacing the pipe running across the top of the engine directly after the Y piece.

Chargecooler Chargecooler Internals

Air passes through the large openings in each end, and water passes through the two smaller openings on the side.

With space tight at the front, and not wishing to dump the heat from the chargecooler in front of the engine coolant radiator, I have decided to mount the other part of the chargecooler at the back of the car. Utilising a heater matrix element, I have begun to make up a box which will sit under the car, in the position of the existing fuel tank, between the two exhausts. This will primarily work by just forcing air through the core, but a fan is also added to aid cooling when at low speeds or when stationary, which will activate based on the temperature of the coolant within the chargecooler system, completely independent to the engine coolant system.

Chargecooler box Chargecooler box

Finally, the trailing arm mount on the driver’s side for the rear suspension was fully boxed in and tied into the chassis. We will repeat this for the passenger side.

Rear suspension mount boxed in

And finally, just because… another quick video:

Keep cool and wire on

Now that the car can drive again, my dad has been able to move it around when he needs access to his workshop. However, doing so means starting the engine from cold each time, and something hasn’t been quite right with it, it’s not been wanting to fire up first time. Once it’s going, and it’s got a little warmth, it will restart fine – but it’s also been running exceptionally rich, dumping in lots and lots of fuel.

Something didn’t seem quite right, so it was time to don the diagnostic hat, and see what didn’t look right.

The VR4’s ECU has a diagnostic connector, physically similar to OBD (On-Board Diagnostics), but uses Mitsubishi’s own communication protocol. Luckily, someone has figured this out, and for just $25, you can purchase EvoScan, which allows you to read data from the engine ECU. A small price to pay for the awesome features you get. You have probably seen a shot of this running on the laptop in a previous video, along with the MAP-CAL software for the MAP-ECU unit.

Taking a look at all of the various sensors you can read, I noticed a couple of things were odd. Firstly, the TPS (Throttle Position Sensor) value was a little off – with the throttle fully closed, the value should read approximately 11.5-12.5%, and with the throttle fully open, around 96%. With the throttle closed, this was reading around 15%.

Adjusting this is quite a simple process, thankfully. Firstly, place a 0.65mm feeler gauge between the stop and the butterfly wheel to partially open the throttle. Then, remove the connector plug, loosen the two bolts holding the TPS sensor, and rotate the sensor until the point where you lose connectivity between the bottom two pins – these are the pins for the Idle Position Switch – when there’s continuity between the two, the throttle is fully closed.

With this adjusted, the TPS reading in EvoScan was a more healthy 12.2%

I also noticed that the Coolant Temperature Sensor was reading -59 degrees C. I know it’s been a cold June, but not quite that cold!

Checking the sensor, we found no continuity between the sensor ground and the relevant sensor ground pin on the ECU. Tracing back the wiring, it seems we’d omitted the ground wire – if that’s our only wiring issue so far with the amount we’ve removed and chopped, then I’m not too displeased!

All the other sensors looked OK, no readings that jumped out as being wildly inaccurate.

The last thing to look at was on the MAP-ECU. On this, you also specify the throttle position values for fully closed and fully open – as I’d adjusted the throttle position sensor, I had to resample the values for the MAP-ECU configuration.

With all of this checked, we tried to fire up the engine – it now bursts into life on the first turn of the key, and seems to be running slightly less rich than it was – it now knows that the coolant is at the correct temperature, so isn’t applying quite such a high cold start enrichment (it adds more fuel when cold)

With it starting and running nicely now, we decided to revisit the cooling system – the Mini radiator was always only a temporary solution until we had found something more suitable, which I now have.

After removing the temporary radiator and fan, I attached a more suitable fan to the car, as well as mounting a radiator that will fit in the space available – this is from a Skoda Felicia – and is within 1cm of the dimensions we scribbled on the bulkhead a few months ago. It will be replaced with a new radiator in time – whether it’s a replacement OEM one to the same spec, or whether it’s a higher performance custom-made job – well, I’ll see how it fares with this standard one whenever it’s on the road.

Cooling fan fitted Radiator - from a Skoda Felicia Radiator fitted

I HATE WIRING.

There, I said it. There’s so much excess wiring from the VR4 that I’m not needing in this car, and because everything’s in different places, and the car is smaller, there’s lots of wiring to do. It’s a daunting process, and it’s not often I feel like doing it.

However, it needs doing, so I decided to tackle it.

I started off by trying to undo the spaghetti tin of wiring that I had draped over the passenger footwell, to try to make some kind of sense of it.

This was a process that took a good couple of hours, just taping together wires that run parallel for more than 6 inches to see what goes where. And when I was done with that, I’d not removed any wiring, it wasn’t the final product, but it at least gave us a chance of seeing what goes where and what subsequently doesn’t need to be there.

Then came the task of tracing a wire, cutting it, re-routing it, and joining it back together. Repeat this hundreds of times for a different coloured wire, over and over, for hours on end, with only a few brief breaks for a cup of coffee and a biscuit…

Excess wiring removed Still some more wiring to tidy

It still looks a bit of a mess, but wiring is a task where you need to do 95% of it before it looks like you’ve actually done anything with it.

On the plus side, the passenger floorpan is now mostly clear of wires, there are a number of bits which are properly loomed up and neat, and there’s a large pile of wires and connectors which have been removed, the only real evidence of actually having done anything…

Propped up and shafted

Having worked out the rough ride height with our temporary bracketry and solid bar, I ordered some adjustable shocks and springs, and we re-did the lower mount, and reinforced the top mount. The lower mount will have some additional bracing and welding completed the next time the axle is removed from the car and we can get to it all more easily.

Upper spring mount Lower spring mount Spring

With the de-dion now moving up and down like it should, we need to get some drive to the wheels.

The Nissan diff is about 50mm longer than the Anglia diff, so the Nissan propshaft, which bolted straight up to the Anglia diff, is now 50mm too long to bolt up to the Nissan diff.

Being a two piece propshaft, we pulled the rear part off, and set about removing 50mm from the length. By clamping it in the vice and utilising a spirit level, we were able to get a clean cut to reposition as necessary.

Propshaft preparation Propshaft preparation

With the propshaft cut to length, next to tackle is the driveshafts. The Anglia is a lot narrower than the Nissan, so a touch more than 50mm needs to be removed from the overall width.

We cut the driveshaft down, and with the use of a lathe and an angle grinder, we V’d the ends to provide a large surface area to weld the two ends back together.

Driveshaft preparation

Once welded together, the driveshafts were checked for straightness on the lathe, and the boots were refitted, albeit much closer than previously, and the new driveshafts are attached to the car.

Nearside driveshaft Offside driveshaft

The propshaft and driveshaft modifications done here may not be the final parts used on the car. What they will do, however, is allow me to put something together, which will be at least enough to move the vehicle under its own power, and prove the concept. They may stay on the car, they may fail spectacularly the first time any serious power is applied to them – if they work, brilliant, if they don’t, all I’ve lost is a couple of hours of time, and I’ll get some made up elsewhere.

A couple of shots of the diff mountings now. These are rubber bushes within a length of tube, with a long bolt going through into the body. Should absorb some of the vibrations/noise coming from the diff…

Rear diff mount Front diff mount Front diff mount

And finally, the completed article. One completely home-made, custom rear axle, to my exact specifications, and should be strong enough to take whatever power the engine can throw at it.

Completed rear axle

We then couldn’t resist driving it outside for its first little photoshoot outside of the confines of the garage, and to enjoy the surprisingly good weather.

IMG_4824 IMG_4826 IMG_4829