Alpine A610 Turbo - Megasquirt Conversion

[DaveL485]

All the senors take a while to respond so it won't be giving you enough fuel.

Its called transient throttle in my software, and its exactly what you say - the sensors don't react as fast as the supersonic pressure wave travelling across the inlet manifold.

Andy, think of it like the GT Turbo carb, you know when you look down the throttle choke and rev the engine you see that little brass enrichment jet squirt fuel into the inlet? Thats mechanical/instant and this transient throttle config is exactly the same as that. Its a sudden enrichment as soon as the throttle twitches, before the MAP sensor knows anything has happened.

 

[r5gordini]

Thanks @DaveL485 - I have now tuned transient throttle. It's working pretty well, but can tend to be rich initially so it needs a bit more work.

I'm also slowly tuning ignition timing and boost. The OE valve (Amal) is working pretty nicely and the ECU can open it up to any level I command - so far releasing 1.5 bar boost. I am aiming for 2 bar eventually but taking things slowly.

Quick question - is there any advantage/disadvantage for boosting at low revs?

I can build 1.5 Bar at about 2000 rpm. Good idea or not? Should I back off boost in these ranges and leave high boost for higher rev ranges?

The advantage of a 3L engine and a T3 Turbo. Lag is greatly reduced!

Andrew

 

[DaveL485]

is there any advantage/disadvantage for boosting at low revs?

Massive torque at low revs = bent rods if you're not careful!

 

[r5gordini]

Eek! Thanks Dave - I don't think it has massive torque down there as it doesn't feel that quick. It doesn't feel that quick overall anyway. Still a lot of ignition timing tuning to do. Getting closer and closer to going on the rolling road! Had many problems with the rear brakes, which I think I have finally sorted just today.

Bigg Red used the wrong seals, then I stuffed things up with the seals on the sliding pins, meaning that the rubber got stuck between the pins and the calipers, leading to sticking brakes when hot. Got no seals at all at the moment. Just wanted to prove that was the issue. Going to fit some new ones shortly. They are very easy to trap between the end of the sliding pins and the pad carriers... Or they melt when the calipers get hot!

Andrew

 

[DaveL485]

It's a good job brakes aren't a critical safety feature isn't it!

 

[andybond]

“I make my cars to go, not to stop.” — Ettore Bugatti,

 

[r5gordini]

so.. an update! I took the car to a rolling road local to me. Great guys there! They confirmed the offset of the trigger wheel. I was a few degrees, well, quite a few degrees off! It was very difficult to set on my own. It necessitated him using a strobe and a mirror down by the exhaust.

We did put the car on the dyno. He set a base ignition map but wasn't able to do any more because my knock sensor module wasn't working. I hadn't been able to tune it myself, so I now need to test the sensors and then try to tune the module. I'll need a friend for that!

On the plus side, I did see some BLUE flames out of the exhaust. Seriously cool:



Andrew

 

[Adey]

cool update, i bet your chuffed. one step closer at least

 

[andybond]

Flames rock. FACT

 

[r5gordini]

Flames do rock! And yes I am chuffed!

Buuutt..... Even better flames in this post!

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:





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

 

[Brigsy]

Sounds awesome, should be fun on the roads. Whos doing the mapping ?

 

[r5gordini]

Sounds awesome, should be fun on the roads. Whos doing the mapping ?

It already is! I'm hoping for closer to 300bhp when done but I fear that may be optimistic.

Hidden Performance in Sandwich, Kent. They are nice and local and seem really interested in my car. I know a lot of car type people in my local area so maybe they are treating me nicely in order to spread the word as they've not been in their current location for that long.

They specialise in Toyota Supras and other Japanese cars. There was an absolute minter of a Skyline in there when I visited. They also sell ECUs and specialise in auto to manual conversions and fitting Supra engines to BMWs of all things.

How does 600whp in an E36 sound? Apparently the Supras now develop more power with a single, modern turbo than they did with the twin turbos back in the day.

Their dyno is a proper 4wd one too. So bring your Quadras to them!

Andrew

 

[Gary]

Must be satisfying with all the work you have put into it, Top Job!! Hope you don't mind me quizzing you when I finally get to do the wiring for my 5

 

[DaveL485]

Well done mate, good to see it working!

 

[niconkk]

updates?

 

[DaveL485]

updates?

The update is, he's got married and had a baby lol

 

[Big Steve - Raider]

The update is, he's got married and had a baby lol

And bought a Roller..