Breganzane EFI Triple

Here's a cool vid showing a compilation of two days worth of EFI tuning.

Cheers
Steve B

Hi Folks,

Bit of a blog update on the EFI bike...

The RGA has been out of action for a while now while I work through some problems that have cropped up. I had some strange running gradually developing, which was eventually tracked down to blocked filters causing fuel pressure fluctuation. Then the injectors got a gut full of crud after I changed the filter, which also took some tracking down.

I fitted a new crank sensor arrangement, and although the design and fit is perfect, for some reason it has caused some starting problems to develop. I am working with Autronic at the moment to try and track down why this is happening, because there does not seem to be a reason for it.

I decided to inspect the new alternator, which had been working fine and had cured all my electrical supply issues. A good thing I did, because there was a small problem with it, for which I'll need to make some revised parts. Haven't had time as yet.

But once running the bike is hammering again as it did before all the fuel supply issues, really goes well. I just need to fix the small problem with the new alternator and the starting issue and things will be looking pretty damn good.

There's always something....

In terms of an ECU, I had initially been leaning towards using a Microsquirt - a miniaturised version of the DIY Megasquirt. But its release was beset by multiple delays, and by July 2007 I wanted to get going and could wait no longer. Since then, the Microsquirt has been released and seems to be getting good reviews, but its big disadvantage for a 120 is that it only has two fuel and ignition outputs, requiring an additional kludge to fire all three coils. It may still turn out to be a good budget ECU for use on a 180 or any type of twin.

After considerable research I settled on an Autronic SM4, which came with very high praise and could handle all of the ignition and fuel requirements directly, allowing full sequential injection and individual control over each cylinder.

With the arrival of the SM4 I really got going, there was so much that was simply 'unknown' and so I just had to make a best estimation of what would work and try that.
I ploughed ahead and designed and built the high pressure fuel system, crank sensor, camshaft sensor, cylinder head temp sensor and so on. The wiring harness for the SM4 is as much as the whole bike! Finding space for all the various components was similarly a constant challenge, allowing for issues of heat, water, and every Laverda riders friend - vibration!

The initial setup was a bit of a challenge, as I was not only learning how to set up the ECU, but also having to debug the various customised solutions I'd had to employ.

On October 1st 2007, after some false starts, it was ready for an initial startup. With all the timing events dialled in, to my immense joy it started basically on the first attempt and immediately ran and idled - I was pretty stoked! :-) Within half an hour I was riding the bike up and down the street. Even without any prior EFI tuning experience I was very impressed with how easy the Autronic was to tune. However it soon becae obvious that it would require a session on a load brake dyno to map the motor in the higher load areas where it was simply not safe or even possible to do on the street.

Cheers
Steve B

The EFI project started in earnest in January 2006 with the purchase of some throttle bodies from ebay. One of the things that has made this conversion easier in the intervening years is the amount of hardware available from recent model mass market bikes.

I chose bodies from a GSXR Suzuki as they looked particularly suitable for the task. Some design work and a bit of 3D CNC milling saw suitable adapter flanges made up, and soon after the throttle bodies were re-spaced and fitted to the cylinder head for the first time.

This was in about June of 2006, the fitting of the throttle bodies gave the impression of progress but the rest was all a big unknown...

Nothing much happened for a year or so while I finished the chassis upgrade of the RGA and tested the finished result over the Christmas/New Year period 2006-7, the bike running on the original Dellortos. In the background I had acquired a few types of fuel pumps and was looking into the options, finding plenty of packaging difficulties trying to fit all the required components in. There were also countless hours spent researching and trying to find various specific components that were required.

So here are some entries to show how I got to the point of having a running and reasonably well proven EFI Laverda triple.

PART 1:

This has been a pet-project of mine since 1996, when I originally opened the engine out to 1130cc and did some head work. I was advised to get some 36mm Dellortos to suit the ported head by Phil Todd, and was looking at other options. People were just starting to fiddle with EFI systems for bikes, but it was quite costly and as there were few producion bikes with EFI, most parts available were more to suit automotive application and so were usually big and cumbersome.

After some trials and tribulations, in 2000 I took a cheap option and got some Mikuni 36mm CV carbs from a wrecker and got them working on the bike. They provided a huge boost to fuel efficiency, lots more low and mid-range power, but a loss of top end. Still, all in all they were a big improvement on the Dellortos, and the bike was a lot quicker in normal riding, even though it had lost some top speed. All in all it was a success, and the same carbs are still in use on another RGS now, having done more than 40,000km now.

Fast forward a few years, after having the RGA off the road for a while and the 36mm Mikunis donated to another bike, and in the great search for more power I got a set of similar 38mm CV Mikunis with the hope the extra choke size would restore some top end. Those sat around in the 'round tuit' pile till I got the chassis modifications sorted out. Meanwhile I had decided that it really was time to bite the bullet and develop the ultimate induction system - one which would not need upgrading no matter what else I did to the bike down the line. For infinite tuning possibilities EFI was obviously the way to go.

So in 2005 I began to do some research...

To be continued...

Cheers
Steve B