G10 PRV A610 Update

Hi All,

As some of you may remember, I have been installing a Megasquirt ECU on my A610. Due to other projects (getting married, preparing to put my house on the market, making a baby(!) and a Rolls-Royce Silver Spirit), things have been a bit hectic lately.

Now with my need to move house I need to get my A610 mobile again.

So far, I have got it running (very nicely, I may add). It starts, warms up and idles better than it ever did. I think getting rid of the original fuel injectors (I used Siemens Deka 630cc) and the distributor (I used Chevrolet LS1 coils in a wasted spark configuration), have made all the difference.

I took it for its MOT a few months ago but it failed - first on the rear lights (oops - I had messed up the wiring) and then the rear brakes - the offside caliper was ineffective. Lights were easy to fix, but not the caliper. I had rebuilt it myself about a year ago, but it obviously wasn't successful. So I removed both and have sent them off to Bigg Red. Now awaiting their return.

While saving up (life's been expensive!), I decided to take a look at the heater blower. I found that it sometimes stopped working. I couldn't figure out why. At first I thought it was something I'd broken, but its failure was not connected to the work that I'd done.

I eventually traced it (via checking the blower PWM (resistor) module), to what I thought was a faulty connection under a black plastic cover on top of the blower unit. Nothing for it but to remove the whole unit as the captive nuts that were holding the bolts just turned round in the plastic of the unit so I couldn't remove them.

I removed the fuel tank and the bulkhead, after breaking one of the bolts holding that on....

Then investigated further. Under the cover, everything was fine. It was only when investigating the blower motor itself that I found that someone else had been there before me! They'd replaced the original connector with spade terminals. They are different sizes but the wrong size had been used for the smaller connector, meaning it was very loose. This led to an intermittent connection. What a pain! I could have fixed that without removing the bulkhead and breaking stuff as I did so!

On the plus side, I was able to check the front crossmember. Good news is that it appears very solid indeed, so I can put my mind at rest over that.

When removing the heater box, the left-hand side of it (nearside) broke off. Old plastic was too brittle. So I bodged a new bracket up to hold it all in place over that side.

I was able to remove the bulkhead and heater without disconnecting the AC pipes or the heater matrix. That was a two-person job, however.

The heater box is now loosely in place now, so I need to bolt it all back in place properly and drill out the bulkhead fixing bolt that I broke. I may just replace it with a pop rivet as there are other pop rivets elsewhere anyway.

Then fuel tank back in, rear calipers on and brakes bled and we should be in business!

My initial drives to the MOT station were very positive. The car responded well and the Megasquirt auto-tune was working very well indeed. Plan is to get it MOT'd then to drive it carefully everywhere, trying to visit every tuning site in the map that I can. I have disconnected the electrical connections to Amal valve for now. Slightly annoying is that the MS pulses it so that it's open under normal running conditions - for best boost response, but the resultant clicking is rather loud.

I'm looking forward to getting the car back on the road! I'll report progress here.

Andrew

[phildini]

.........It was only when investigating the blower motor itself that I found that someone else had been there before me! ......................

[mettersl]

Andrew,
Interesting progress, what does the megasquirt auto tune mode do?
Is this a self optimise approach to building a map? Does it need a wide band lambda sensor?
Sounds interesting if you aren't trying to squeeze performance emvelopes.
Lee

Phildini - hehehe! I didn't think it was! It was a terrible bodge though. I have been able to sort it, so no worries.

Now going to squirt some wax into the crossmember before finishing the assembly. It does look very solid indeed.

Lee - yes the MS does require a wideband lambda sensor to do this - I have one installed, although I may have to move it because it's very, very close to the exhaust manifold on that side. I had to install it quite a way downstream of the turbo. Apparently, wideband O2 sensors don't like hot exhaust temperatures.

The auto-tune measures the lambda at the current MAP and RPM. It tries to optimise it to a pre-defined air/fuel ratio at the various points in the map. It requires repeated visits to each point in the map in order to slowly change the amount of fuel injected at each site.

Here's the AFR map:

AFR Map.png

And my current VE table:

Fuel VE table.png

The VE table is only loosely defined at the moment as I've not properly driven the car yet (save for to and from the MOT station, twice).

I do want to get the car mapped on a proper rolling road as I do want good performance, but this should save some significant dyno time.

Andrew

Where are you based, Chris at EFI-Parts is normally highly recommended for RR tuning and he has done a good few GTAs and all sorts of R5s used for fast road use as well as drag. He is honest and will give you good advise , works weekends and evenings but often booked well in advance. Allways best to send him an enquiry email first.
http://www.efi-parts.co.uk/engine-mapping.php

Thanks, Simon. I am miles and miles away from Chris! He's a great guy and I have considered him but I don't fancy the 5 hours each way...

I've found a RR in Canterbury that would be prepared to tune it for me.

Maybe I could turn a visit to Chris into a mini-holiday?

First step is to get the car MOT'd!

Andrew

Oh - I'm in Deal, Kent - right on the coast.

Chris also told me that a good tuner should be able to tune any ECU, they all pretty much have the same basic features. I am sure MS can guide you if needed too. Fingers crossed for good results.

Thanks!

Andrew

Try engine dynamics they are a Renault tuner for many years and closer too you. Scoff @efiparts is a legend mind you.

Thanks for the hint! I'll look them up.

Anyway - the good news is that the car (eventually) passed its MOT on Monday!

It failed on Saturday due to:

Directional rear tyres fitted the wrong way round (oops! my bad)
Emissions - CO waaay too high...
Incorrect beam pattern nearside headlamp
Offside rear fog light not working
Left-hand rear indicator not working

Aargh. After I'd worked so hard on it!

The rear tyre issue was easy to sort.
Emissions - the Lambda sensor stopped reading part of the way to the MOT station - bear in mind that this was the furthest I had driven the car up until now. My suspicion is that the sensor is too close to the left-hand exhaust manifold and is getting too hot from radiated heat. This is borne out by it working just fine (subsequently) at night! For the retest I managed to reduce the fuelling at idle.

Incorrect beam pattern - I had fitted HIDs at some point. Initially, I was very pleased with them, but I found their startup time annoying when switching from main beam back to dipped - a few seconds of near blindness wasn't fun! And the light output of the standard headlights may have been worsened by a PO fitting some anti-chip film over them. So I just decided to go back to standard halogens. I can report that they seem much better since I removed the film. It's not as if the headlights are exposed to stones most of the time anyway! Plus I have a spare set.

The rear lights not working was particularly annoying. For some reason, the connectors seem very vulnerable to corrosion and bad electrical contact. Since taking the car off the road to do the MS conversion, I have found all sorts of connections go bad. The car really seems to suffer from not being used - even being kept in a dry garage doesn't seem to prevent these troublesome issues!

Initial driving impressions? The car is so, so much easier to start. I still need to do some tuning of the cranking parameters but I now know that the car will always just start. Last night, it started immediately I turned the key. It has never done that before. In some instances in the past I would have been afraid that I would flatten the battery before it started. No such worries now.

It also idles much more smoothly than ever before. The Deka injectors seem to be really very special. Large flow yet controllable at very small pulse-widths. Nice job, Siemens!

Tuning the car seems to be going well too - I've even made some excursions into full throttle and medium boost territory, although the Amal valve is still disconnected. The tuning map is slowly sorting itself out and looks like this now:

Screenshot at Sep 20 14-15-48.png

You'll notice that I haven't yet managed to visit the low RPM, high boost cells (unsurprisingly). Slightly worrying is that I do appear to have hit the high boost mid rpm cells - even up to 200kpa... Argh! I've just realised something. I am eventually hoping to run 2 bar of boost, so my tables are going to need to change to a 300kpa maximum. That's annoying. Miscalculation on my part. I'll need to export the tables, regenerate the AFR tables and retune.

I've noticed the car feels like it's holding back quite a bit under moderate throttle - that might be due to the lower boost than standard, or fuelling or ignition not being quite right.

I feel like I am making progress.

Andrew

I might not need to retune all the way - Tunerstudio can interpolate if I change the bins on the Y axis.

What do people think on the granularity of the Y axis? If I evenly space it, the map running off boost occupies half the table; boost occupies the other half.

Do I need more resolution and accurate fuelling at part throttle, or is it more important to be bang on during boost? Or should I just split the table evenly?

Thanks,

Andrew

Chis @ EFI-Parts is probably your man to ask.

Another update... Car tuning is going fine, but the Lambda sensor has failed, as I thought it would.

Amazing service from Chris at EFI parts. Ordered lunchtime yesterday. Here this morning!

Now just need to get the new bung welded further down the exhaust. I am hoping to make it to Origine RS at the weekend. However, the car is in the shop at the moment having the brake flexi-hoses renewed, gearbox oil changed, plus a couple of other bits, so it's a bit touch and go! There are complications with the flexi-hoses - the rigid hoses at the rear need replacing/fixing.

If necessary, I can drive the car without the Lambda sensor. The garage hasn't scheduled enough time to get the exhaust off, so providing I get the car back by Thursday I can probably get the new bung welded in time.

Andrew

[stephendell]

Hope to see you on Saturday then