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DB2SR - winter project turns into lockdown project
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hindsight



Joined: 13 Feb 2010
Posts: 126
Location: Central Scotland

PostPosted: Sun Apr 26, 2020 3:21 pm    Post subject: DB2SR - winter project turns into lockdown project Reply with quote

I thought I'd write this up here, as I'm sure some of the regular visitors will find some of this interesting.

Over winter I had planned on giving the DB2SR a service - nothing particularly special, just a set of belts, oil, clearances - the usual stuff. It doesn't get run hard, and doesn't get a lot of miles, so I wasn't planning on doing a lot of work on it, but it didn't exactly work out like that...

After stripping the bodywork off, and starting the service, I figured I would just pop the horiz head off, just to check whether it still had the original bore size. As I measured the 92mm bore (904cc), a glimmer of an idea started to emerge, which soon escalated..


Original heads and barrels off..

In the above picture, note the flywheel with the drillings around the circumference - this is the 60-2 missing tooth timing signal picked up by the normal flywheel pickup that the ECU uses for timing information, and is specific to the DB2SR. It also meant that I couldn't put a super-lightweight flywheel on unfortunately.

Fast forward two months, and it now has HZ (ST2) cams, a carbon race exhaust from Japan, and is running on 944cc with the option to go to 984cc in the future (or potentially 1068cc - but that might be pushing it a bit..)


944 barrels/pistons on, heads fitted with ST2 cams and reshimmed to match.

It ran pretty well with 944cc on the original ECU, but a trip to the local Dyno shop clarified that the fuelling really ought to be adjusted.



Unfortunately though, information on the original TDD ECU is sparse, and the software required to interrogate it or to interpret the chip image unobtainable (I tried contacting TDD directly, but after initial interest, they went silent).



I swapped emails with Bernhard Bludau in Germany, who appears to possibly be the only person on the planet that can cut new EPROM images for these ECUs (and indeed, it seems that he installed a chip into this very bike 22 years earlier!). However - as the world went into C-19 lockdown, communication with Bernhard unfortunately ceased - I do hope he's safe and well.

I had previously been thinking over how to adjust the fueling during the winter, prior to finding Bernhard, and I've also considered what I'd do if this rather unique ECU ever terminally failed - and it seemed that the best way to proceed was to build a new ECU, running modern software. I figured that might be a good project in the future when I had more time on my hands.

More later...

Regards,
Mike
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2bims



Joined: 03 Apr 2010
Posts: 7289

PostPosted: Sun Apr 26, 2020 8:03 pm    Post subject: Reply with quote

I'm looking forward to more updates.....why didn't you take off the rear swinging arm>??

Front cylinder....is the oil cooler mounted differently on the SR model? You seem to have the valve cover with the moulding on to mount the oil cooler on the top set of valves of the horizontal cover and not the underside....where it is at least on the DB2 carbie version...And bimota cunningly use another one of these that ducati doesnt use...on the rear cylinder to mount the battery box onto also.....why reinvent the wheel> Something that bimota normally do do...Oops....I said do do there...didn't mean to.....
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hindsight



Joined: 13 Feb 2010
Posts: 126
Location: Central Scotland

PostPosted: Sun Apr 26, 2020 8:32 pm    Post subject: Reply with quote

Hi Steve -

2bims wrote:
I'm looking forward to more updates


Good stuff.. always good to get feedback, so thanks Steve - I'll get the next instalment posted in the next day or so..

2bims wrote:
why didn't you take off the rear swinging arm>??

Simply because there was no need to do so for what I needed to do. I didn't have any concerns that the bearings were in need of replacement, so just left that for another day.


2bims wrote:

Front cylinder....is the oil cooler mounted differently on the SR model? You seem to have the valve cover with the moulding on to mount the oil cooler on the top set of valves of the horizontal cover and not the underside....


Ah. Good spot - I'd forgotten about that - just a reassembly error that was corrected soon after the photo was taken Laughing

Mike
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vort28



Joined: 22 Mar 2010
Posts: 2194
Location: Northwest , UK

PostPosted: Mon Apr 27, 2020 9:16 pm    Post subject: Re: DB2SR - winter project turns into lockdown project Reply with quote

hindsight wrote:
- and it seemed that the best way to proceed was to build a new ECU, running modern software. I figured that might be a good project in the future when I had more time on my hands.

More later...

Regards,
Mike


Build a new ECU, that seems easy then ??? NOT !!!!
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brian



Joined: 22 Aug 2011
Posts: 3769
Location: Australia

PostPosted: Mon Apr 27, 2020 10:40 pm    Post subject: Re: DB2SR - winter project turns into lockdown project Reply with quote

vort28 wrote:
hindsight wrote:
- and it seemed that the best way to proceed was to build a new ECU, running modern software. I figured that might be a good project in the future when I had more time on my hands.

More later...

Regards,
Mike


Build a new ECU, that seems easy then ??? NOT !!!!


I was thinking the same thing Stu! I would find it a big enough challenge to build a new battery box, let alone an ECU Shocked

Comes down to knowledge and experience I guess
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2bims



Joined: 03 Apr 2010
Posts: 7289

PostPosted: Mon Apr 27, 2020 11:52 pm    Post subject: Reply with quote

indeed....I'd end up buying a crashed Multistrada 1000 or 1079....and sticking that engine in with its Ducati fuel injection, ecu and electrics and clocks...and even then I'd struggle....there was a lovely DB4 for sale in the UK that Ducati Coventry had done just that with it...and tuned it....and some other trick bits....but from the outside...it looked standard Db4...bodywork, paint etc
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hindsight



Joined: 13 Feb 2010
Posts: 126
Location: Central Scotland

PostPosted: Tue Apr 28, 2020 8:12 am    Post subject: Reply with quote

2bims wrote:
indeed....I'd end up buying a crashed Multistrada 1000 or 1079....and sticking that engine in


I absolutely agree that this would have been the more efficient solution overall if I had initially planned to do the whole lot - but back in December when I started the service - it was just going to be belts and oil, and then it was only a month or so ago that I decided to tackle the ECU.. Shocked

Additionally - I was keen to maintain the original engine number and period originality where possible, but also to be able to easily revert to original (for example, I've got the original 92mm barrels, pistons and cams sitting on the shelf, just in case)

I'll get more posted this evening.. Wink

Mike


Last edited by hindsight on Tue Apr 28, 2020 9:44 am; edited 1 time in total
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welshlamb



Joined: 09 Mar 2011
Posts: 592
Location: South Wales , Nr. Abergavenny

PostPosted: Tue Apr 28, 2020 9:05 am    Post subject: Reply with quote

2bims wrote:
indeed....I'd end up buying a crashed Multistrada 1000 or 1079....and sticking that engine in with its Ducati fuel injection, ecu and electrics and clocks...and even then I'd struggle....there was a lovely DB4 for sale in the UK that Ducati Coventry had done just that with it...and tuned it....and some other trick bits....but from the outside...it looked standard Db4...bodywork, paint etc


Tempted by that weren't you? If I remember it sold VERY quickly and I dont think its shown its head since. A VERY tasty bike that was!!
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2bims



Joined: 03 Apr 2010
Posts: 7289

PostPosted: Tue Apr 28, 2020 10:31 am    Post subject: Reply with quote

It was later sold on again....but the original 900 lump it also came with....was sold separately...7500 first time around...trick suspension and engine goodies and 1078 lump fitted....vort saw it first on fb...was going to see it that day...it sold in under 2 hrs...
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hindsight



Joined: 13 Feb 2010
Posts: 126
Location: Central Scotland

PostPosted: Tue Apr 28, 2020 8:50 pm    Post subject: Reply with quote

vort28 wrote:
Build a new ECU, that seems easy then ??? NOT !!!!


Yes, you're very much correct - building a whole ECU, and writing the software to go with it is a huge undertaking that would take months - not practical for what is essentially a one-off ECU.

However - it's not necessary to create entirely from scratch - during research, I'd become aware of the Speeduino project, it's an open-source engine management system designed to run on an Arduino microcontroller. I was initially quite sceptical when I first read about it, but after researching it, and doing some maths on the clock speed of the microcontroller, it became clear that it could well work nicely, and run at least as well as a 25 year old equivalent (probably better), and also have the benefit of being completely open for tuning.

Ultimately the ECU is just a computer.. It takes a bunch of inputs (Air/Coolant Temperature, Throttle Position, Crank Position), and figures out how much fuel the engine needs, and when to fire the spark plugs. I oversimplify it for effect obviously, but at a high level - that's it.

Researching the typical setup for a Speeduino ECU confirmed that all the inputs and outputs ought to be compatible, with a little know-how.

The Bimota (and its ECU) isn't exactly blessed with good documentation!. There was plenty that had to be figured out in order to reverse-engineer the EFI system, tracing all the wiring on the bike, identifying all the relevant components. The wiring diagram for the carbie DB2 came in handy once or twice, but as can be imagined - the DB2SR EFI loom adjustments are not covered by that document at all.

I'd also been researching specialist commercially available Speeduino compatible boards - these take care of the majority of the electronics required to interface the CPU of the microcontroller to the inputs/outputs, rather than them having to be all built from scratch. That seemed to be the best way forward while I prove the concept with a prototype board, so that I could concentrate on building a prototype interface and understanding the software configuration required to interpret the sensors and get the timing right.

Here's what I came up with - it's not pretty - it looks a bit like a bomb at the moment.





It's also not particularly robust - but it proved a point and allowed me to improve the design over a few iterations. Last weekend I solved the last puzzle and the engine now runs beautifully, and although the bike was running only on the bench - it certainly seems more potent than when the OEM ECU is running the bike (which would be natural - the new ECU is calculating the fuel for 944cc, where the old one was previously fuelling for 904cc).

It can also connect to a laptop by either USB or bluetooth, which allows me to visualise what it's doing, which has been tremendously helpful as I've been configuring it. In time, I'll need to adjust the fuelling, as I think it's a little rich at the moment.

It's a shame this forum doesn't allow the markup to fully embed youtube vids, but click on the image below for a link to a youtube vid of it running from a cold start:



https://youtu.be/WzQIyEULSSY

The eagle-eyed amongst you might notice that the air temperature sensor is reading 21C. That's seems to be a new feature that wasn't present a few days ago - I'm reasonably confident that it's not that warm in Scotland right now, so I'll need to have a look at what is going on there. I also think it's overfuelling at the moment, so bear in mind that this is it in a raw, untuned state.

So far, I'm pleased with the progress and success - but I'm not done yet -
* I've designed and ordered a PCB to replace the prototype interface board, for which a friend is going to 3d-print an appropriate enclosure for it. That will make it far more robust, and hopefully trustworthy for the road (at some point in the future).

And once that's done:
1. It's also capable of connecting to a wideband oxygen sensor (which would need to be welded into the downpipe), allowing it to self-tune the fuelling settings.
2. I've started to further evolve the schematics so that it doesn't require the specialist (expensive) microcontroller, and can be run natively on a £10 Arduino microcontroller board - this will make the interface board much more complicated and expensive, but if the microcontroller fries at some point in the future, a generic Arduino board can be sourced far more easily than the specialist device.

I've also got a few other ideas of where else I could go with this, but best that I get the basics tested first.

Mike
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Bud977



Joined: 03 Mar 2013
Posts: 525
Location: Sydney

PostPosted: Tue Apr 28, 2020 9:39 pm    Post subject: Reply with quote

Love your work. So did you have to write the fuel and ignition maps from scratch?
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hindsight



Joined: 13 Feb 2010
Posts: 126
Location: Central Scotland

PostPosted: Tue Apr 28, 2020 9:56 pm    Post subject: Reply with quote

Thanks Bud

I've not yet touched the fuel map - it's running on the default speeduino settings, but it definitely needs work.

I've done a little tweaking of the ignition map, which I took from a recommended 900ssie map. There is a separate setting for cranking ignition advance. When I measured the original ECU, the cranking advance was crazy - like somewhere about 16-19 degrees BTDC - bringing that right down to 6 degrees BTDC has improved the starting beyond the original ECU.
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vort28



Joined: 22 Mar 2010
Posts: 2194
Location: Northwest , UK

PostPosted: Wed Apr 29, 2020 8:48 am    Post subject: Reply with quote

Wow, that is pretty impressive !!!!

You make it sound /look so easy !!!!
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DB1 860



Joined: 23 Mar 2014
Posts: 177
Location: Sydney

PostPosted: Wed Apr 29, 2020 11:05 pm    Post subject: Reply with quote

Wow Impressive, So Mike when You increased the bore to 944cc who's pistons and barrels did you use?
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2bims



Joined: 03 Apr 2010
Posts: 7289

PostPosted: Thu Apr 30, 2020 5:57 am    Post subject: Reply with quote

vort28 wrote:
Wow, that is pretty impressive !!!!

You make it sound /look so easy !!!!


I agree with the first comment.....but certainly NOT the second......electrics....the work of demons and goblins that live at the bottom of the garden.....He reckons he's dumbed it down for us and "simplified at high level"....so we understand....I dont.....I am weak and feable and cringe if a bulb blows or a fuse needs replacing....I am not worthy.....But I am impressed...

Yeh...Forum is OLD Skool....you can put up YouTube links to click on....it is from 2002 when it was set up....and all that was available...still clunking around and here today 18 years later.....at least "unlike" FB....when you start a thread and comment...its there forever more...for anyone to see and be amazed....and you get email updates when there is an update....which is more than can be said for FB...who only choose to inform you of updates as they choose....usually from your top ten posters...and then theres the adverts....none of that here

Keep up the good work...but I am no use.....Could you not get the settings from a Ducati ST2....which is 944cc and magneti Marelli fuel injected ecu?
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