Further A610 tuning questions

It seems we are mixing topics! Tony's V8 build and my MegaSquirt.

No matter...

Anyway, it appears that (at least some parts of the) knock sensors and detector are working! I managed to adjust it so that it showed knock even with the engine idling(!) and MS did indeed retard the timing.

Then I backed it off a bit so the knock light extinguished, then restarted the engine. As the engine started, knock was shown and then it wasn't as the engine settled down.

So I think it just needs adjusting properly. I will still do the test with headphones and see if I can adjust it myself but it may need tweaking on the dyno. It's definitely a binary knock sensor - knock is either detected or it isn't.

I've ordered a headphone amp so I can listen to the knock sensors with noise-cancelling headphones - maybe best to do with a friend...

Andrew

Time for an update! I took the car to the dyno again. This time he was able to do some tuning but hasn't finished yet. A few issues getting started - we uncovered a bug in TunerStudio and MegaLogViewer - the tuning and log viewer apps I am using! And then a couple of issues with the car...

He started off very conservatively and added more ignition timing, then fuel, then boost, then went through it all, while listening for knock! Started off at 145 bhp (embarrassing) and moved up to about 215bhp towards the end, but with more torque than standard.

A few things at play... the dyno operator didn't realise the engine is low compression until after the session (he was not familiar with the car) so was playing it very safe with the ignition timing. Also, the knock sensor arrangement I am using is still suboptimal, so I am doing some more research on how to make that better. What ultimately stopped play, however, was the fact that the fuel was tapering off in the high rev ranges at high boost. We suspect a blocked fuel filter, insufficient voltage to the fuel pump or a faulty fuel pressure regulator (or a problem with the OE regulator).

Next step is to investigate fitting a fuel pressure gauge. I'm hoping to find an electronic sensor that I can interface with the ECU so I can log it. Then I will monitor fuel pressure on the road and then start replacing things one by one to track down the issue.

In the meantime, he left me with a safe tune of about 200bhp so I can at least enjoy the car in the meantime.

While I was there, he also tuned in some highly antisocial pops, bangs and flames, which I was able to record and post on YouTube:

https://www.youtube.com/watch?v=sWBkjSV ... e=youtu.be

Serious Flames.png

Some of the flames were pretty impressive!

Andrew

Oh and before people chip in saying "he should have known about the low compression"... yes you're right, he should have, or I should have told him or somethin', but...

I was there for nearly 5 hours, most of which was spent on the dyno. He charged me for 2 hours because it wasn't a complete tune and we were learning together. He is pretty experienced, just not with Alpines!

Andrew

[BIG_MVS]

Erm pardon my ignorance but last time I checked mine had 250 bhp without any of this faff. What did he say you could get up to with a few more hours on the dyno?

Well it's not just about the bottom line power for me. My reasons for doing the ECU conversion are many. I don't know if I need to repeat them here?

Briefly...

Improved reliability
Improved diagnostic capability
Improved starting
Better driveability
Better tunability
Removal of the earth strap of doom (yes I know your feelings on that one)
And yes, some of these may be perceived benefits but I think they are!

But most of all, because it's fun and interesting and I just wanted to!

Right now I will settle for stock power and torque but let's see how we get on. It is a project and I am having lots and lots of fun and learning a lot in the process!

Andrew

And he did not give me an expected figure but I fear he is being overly cautious about the timing because of the knock sensor issues but I think I have a solution in the works. More when I have investigated further.

Keep it up, I am looking at doing something one day with mine.

Thanks! I'll post again here as things unfold. I have done a lot of research on fuel pressure senders and fuel pressure regulators. As things stand, in order to fit a sender I'd have to fit some kind of union or T-piece to my nicely crafted fuel hoses, so I think it makes sense to fit an aftermarket fuel pressure regulator which comes with a fitting for a gauge. Then I can eliminate the OE regulator from my enquiries and have a method of monitoring the fuel pressure at the same time. There's a spare analogue input I can use on the ECU that will enable me to record fuel pressure from an electronic sensor. I may even have put some spare wiring in the loom for a sensor I didn't think of first time around, but I can't remember right now! If not, it's a bit inconvenient to add some more wiring but I could just rig something up temporarily. After all, I'm not expecting to need to record fuel pressure under normal circumstances.

I'll post back when I've decided which FPR to buy. There are many options but after what happened with the fire on the GTA on here recently, I don't fancy skimping on quality, although I think I heard that the takeoff from the filter for the gauge may not have been up to scratch.

More later.

Andrew

What boost had he set that at? He should have at least started with standard boost to map it and then worked his way upwards. Can't be running more than 4 or 5 psi to make that power if its flywheel figure. 200 at the wheels would be pretty close to a standard car.

Thanks! Struggled to get 200bhp with standard boost. Just don't think he advanced the ignition timing enough. I think he added another 5 psi on top at the max but then had the fuelling issue. We are hoping to get more soon once I have sorted the fuelling issue.

I'm not sure whether he's measuring wheel or engine horsepower - presumably the former? I have been meaning to ask the question.

Anyway I have just found out that the original fuel pulse/pressure damper is faulty. It looks like a fuel pressure regulator but is the left-hand one of the two "cans" that are responsible for managing fuel pressure. I tested it by removing the vacuum line to it while the engine was running. It spat out quite a bit of fuel! That's not going to help with anything. Indeed it could be responsible for the hot starting problems I am suffering. It could be responsible for the fuel leaning out at high revs and high boost - it could case all sorts of nasties. I now have a choice:

1. Replace the fuel pulse damper and try again
2. Replace the fuel pulse damper and regulator with an aftermarket regulator (and do away with the damper)

What would others recommend? I suspect the damper has been faulty for some time! In fact it could even be responsible for a rich idle condition which led the computer to shut the fuel pump off in the first place.

If I were to replace the pulse damper it looks absolutely identical to this one:

https://www.ebay.co.uk/itm/BOSCH-Fuel-P ... SwpRRWnLNK

Any ideas if it would do? I can't see the part no. on the original one on the car.

Andrew

replace what ever (both) with the modern option.

Thanks Simon,

After a lot of deliberation, I decided to do away with the fuel pulsation damper - it sits between the rails and folks over the 'net seem to remove them on their cars without issue.

I replaced the fuel pressure regulator with an AEM adjustable one. Made a bracket up that I'm too embarrassed to photograph. It's not pretty, but will suffice!

I set it up to deliver the same pressure as the OE FPR. It seems to work very nicely indeed. The car was suffering from hot start issues - now completely cured. The AFR's are much more stable now too and the car runs way better overall. I wonder if this could have been contributing to rich running for some time? The leaking fuel from the failed diaphragm would be being sucked in to the inlet manifold... I also wonder if this might be the cause of the cutouts? Rich fuel mixture, leading the ECU to shut the fuel pump down?

Andrew

Yes i changed both of mine, it will cause all those problems on mine it the main issue was hot starting the starter motor could hardly turn the engine over as soon as I replaced them the problem was solved.

Well it's not just about the bottom line power for me. My reasons for doing the ECU conversion are many. I don't know if I need to repeat them here?

Briefly...

Improved reliability
Improved diagnostic capability
Improved starting
Better driveability
Better tunability
Removal of the earth strap of doom (yes I know your feelings on that one)
And yes, some of these may be perceived benefits but I think they are!

But most of all, because it's fun and interesting and I just wanted to!

Right now I will settle for stock power and torque but let's see how we get on. It is a project and I am having lots and lots of fun and learning a lot in the process!

Andrew

Hi Andrew,

I think the key is you are having fun, enjoying it and learning. Absolutely on the tunability, anything is an improvement of zero, and diagnostic capability. The rest I probably disagree, as you are finding out, it is a system, and it is all the system components and sensors that have to be working to spec as well before you can compare an improvement. I think the reality is closer to the fact that the manufacturers setup given the amount of R&D test and calibration time they put into it, will always be the best for a standard setup. You will never generate map combinations or be able to repeatedly go back to the set of conditions, and same locations in the map given a number of variables- temperature, air density, cooltant & oil temps etc etc, unless you are setting up in a temperature controlled dyno cell; we can only approximate. Having said that we can get close enough, but in reality claiming we can do better is very unlikely... However, when it comes to making changes, and pushing the performance envelope one way or another, you have no choice but do as you, and accept it will be a compromise...

I would get the turbo swapped over now, you have a setup that should yield good results, spend your development dollars with all the upgrades in, than having to go back over it when buying dyno time... You'll probably want bigger injectors too at that point. However you do it, development is expensive, but the..... rewards are great, and much fun can be had... Keep at

Incidently, what centre frequency have you got your knock sensor & amplifier setup tuned?

Cheers,
Martin