Fuel injected 860 GTS

Post pictures of your twin cylinder Bevel Drive Ducati (pre-1985) along with a description here.
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paulh
Cucciolo - the Lil Pup
Posts: 11
Joined: Tue Apr 17, 2007 8:23 am
Location: Central Queensland, Australia

Fuel injected 860 GTS

Post by paulh »

This is my 1976 860 GTS which I have owned since 1980. In this time it has undergone many changes, the most recent being the addition of an engine management system that controls both ignition and fuel. This has been a completely DIY project involving a very steep learning curve and the sourcing of many parts off ebay and elsewhere around the world. I undertook this purely for the challenge and could not be happpier with the outcome.

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Last edited by paulh on Tue Dec 22, 2009 6:12 am, edited 6 times in total.
Vince
750 Sport [BEVEL]
Posts: 203
Joined: Tue Nov 09, 2004 12:28 am

Post by Vince »

Very impressive,one of the Canberra Laverda blokes has done the same to his RGA triple,lots and lots of work,you blokes are crazy but I love it.
Macdesmo
750 GT
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Location: Wide Bay Australia

Post by Macdesmo »

A lot of work must have gone into that to make it run. What is it like to ride compared to the original bike?
cafe*racer
SSD900 Darmah
Posts: 364
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Location: Castro Valley, CA

Post by cafe*racer »

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austduke
Cucciolo - the Lil Pup
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Joined: Sun May 18, 2008 5:17 am
Location: Sydney

Post by austduke »

Very impressive indeed. Firstly how well does it run?
Also what kind of voltage regulator are you using?
Great job!!
paulh
Cucciolo - the Lil Pup
Posts: 11
Joined: Tue Apr 17, 2007 8:23 am
Location: Central Queensland, Australia

Post by paulh »

cafe*racer

how did you do that? I followed the instructions using the 'Img' buttton but only seemed to manage the adding of the tags around the url. When I previewed the post all I saw was the url with tags around it, no image displayed!
cafe*racer
SSD900 Darmah
Posts: 364
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Post by cafe*racer »

You have to hit the blue "Close Tags" after adding each Img...I'd like to know how your performance is compared to stock as well. Its my understanding that Ducati had a very early fuel injection adapted to the big twins but performance gains were negligible.
paulh
Cucciolo - the Lil Pup
Posts: 11
Joined: Tue Apr 17, 2007 8:23 am
Location: Central Queensland, Australia

Post by paulh »

Macdesmo and austduke

Yes, you are right, it was a lot of work but probably more mentally than physically. The secret was in the planning and understanding how the ECU worked, what it was capable of and how it could be applied to the Ducati twin. It was an iterative process to find the right setup and configuration for my engine. The fuel part of it was easy but the ignition was much more difficult. I could write a book about what had to be considered to make this happen but basically it involved things like what size throttle bodies and what injector flow rates to use (throttle bodies, injectors and fuel pump regulator transplanted from 2003 Ducati Monster 800). These suited the tune of my heads perfectly. Another big issue was fuel supply because I didn't want to modify the tank to fit an intank pump. As a result I was forced to use an automotive inline pump which usually draw too much current an flow much more than is needed for motorcycle engines. The answer was to use a PWM motor speed controller to slow the pump down therefore decreasing the flow rate from 160 to 45 LPH.

Sensors used include a VR magnetic speed sensor on the crankshaft for ECU tach input and ignition timing, a coolant temperature sensor installed in the rear cylinder rocker cover to measure engine temp, an intake air temperature sensor installed under top triple clamp so it doesn't heat sink from the engine, a throttle position sensor operating on the rear cylinder throttle body, a manifold absolute pressure sensor measuring manifold vacuum from both cylinders via a small plenum chamber for smoothing, and a wideband O2 sensor installed in front cylinder header pipe to measure AFR for closed loop EGO control. Mostly this is used for tuning though.

Ok I've probably bored you already with this stuff but believe me this is only scratching the surface. Ausduke, I had to upgrade the alternator and regulator to meet the extra load imposed by the fuel pump, four high energy smart coils, high impedence injectors and the heating element in the O2 sensor. I transplanted a 350 watt alternator from a 1998 Ducati 916. The stator fitted without drama but the rotor was too wide and had to be machined carefully to avoid weakening the structure. This combined with the regulator off a similarly late model Ducati has worked perfectly to overcome a potentially big problem.

So, how does it go and what differences do I notice? Starting is effortless (electric start, though I have kick started with this setup). I control the intake air on cold starting manually by using the throttle stop and after hitting the button it fires straight up and holds the engine speed as determined by the throttle position. Even before getting any where near full temp it will hold a steady 1000 rpm idle and this does not falter no matter how long it idles for. Considering that I haven't yet tuned the acceleration enrichments, the throttle response on quick opening is excellent (compared to EFI Monsters that I have sampled which can be vague and fluffy in this area). Throttle response across the board is impressive and I'm comparing this to the 38mm flatslide Mikunis that this engine was using prior to EFI. The response of the Mikunis was very very good. In general the breathing of this engine is noticeably improved with the 45mm chokes but keep in mind that these heads are a long way from standard. Given the tune of this engine, the most noticeable difference for me is how the EFI has smoothed it out.

The other big difference is tunability. With access to a 12 X 12 fuel map, a 12 x 12 spark advance map, a 12 X 12 AFR map and a sh**tload of other configuration stuff, the sky is the limit for tuning. The real gains to be made with this setup are in spark advance tuning and that will probably mean some dyno time. To say that I'm like a dog with two dicks at the moment is an understatement.

Anyway you have probably been bored sensless by now so I'll leave it at that.

Paul

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Last edited by paulh on Tue Dec 22, 2009 5:43 am, edited 1 time in total.
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abmartin
SD900 Darmah
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Post by abmartin »

My mind is blown! What I don't understand is how you could do all that which is completely beyond my abilities then have trouble posting the photos. Funny how brains work.

Bruce
1979 900SS
Fredericton, NB
Canada
cafe*racer
SSD900 Darmah
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Post by cafe*racer »

Paul, very interesting stuff, I for one am not bored. Maybe you will write that book one day...I would buy a copy. Jordan
Lumpy
SD900 Darmah
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no pic`s

Post by Lumpy »

I can`t get the link to work but love the concept. What injection system did you use?
Lumpy
SD900 Darmah
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Joined: Sun Mar 25, 2007 5:49 am

all good

Post by Lumpy »

All good. Got the link to work and read the rest of thread. Top job sunshine. I`m well impressed.
paulh
Cucciolo - the Lil Pup
Posts: 11
Joined: Tue Apr 17, 2007 8:23 am
Location: Central Queensland, Australia

Post by paulh »

ECU - Microsquirt (http://www.microsquirt.info/)

Throttle bodies - 2003 Ducati Monster 800 (complete with 3 bar Magneti Marelli FPR and 330cc/min Marelli pico injectors and also the throttle position sensor)

Engine temperature sensor - GM style closed element

Intake air temperature sensor - GM style open element

MAP sensor - GM 3 bar (generally not used on Ducati engines because valve timing with big overlap and the use of individual throttle bodies do not allow good enough resolution of MAP to be usefull as an input for fuel and spark control, but I'm an optimist and will eventually try to get it to work)

Wideband O2 controller - Tech Edge 2J1

Wideband O2 sensor - Bosch 4.2 LSU

Fuel pump - Walbro GSL393 (160 LPH)

Coils - Delphi LS2 style high energy with built in ignitors and dwell limiting capability

Crankshaft - ai-tek high sensitivity magnetic speed sensor (7085-1010-120)

High pressure fuel filter - Napa Gold

Trigger wheel - made my own 24-1 wheel from 1/8" mild steel mounted on a boss which is also a split collar clamp for fixing to crankshaft

Lumpy, I have probably gone over the top but I hope this answers your question.
Lumpy
SD900 Darmah
Posts: 329
Joined: Sun Mar 25, 2007 5:49 am

Injected GTS

Post by Lumpy »

Truely a unique and very interesting GTS!! A monument to your engineering abilities. Just don`t tell my old GTS or she`ll be very jealous. The VR speed sensor, is that VR as in VR Holden Commodore??? Also the ECU, I gather this is a programable unit. Please forgive my ignorance as electronic fuel injection is a complete mystery to me. Just trying to get my head around how you got the ignition timing to work in conjunction with fuel injection system. I`m very interested in the ignition system as I am currently saving my bickies to lash out on one of those DMC systems for my 76 GTS as I have a real dislike for the old Ducati Electronica systems and their advance step.
paulh
Cucciolo - the Lil Pup
Posts: 11
Joined: Tue Apr 17, 2007 8:23 am
Location: Central Queensland, Australia

Post by paulh »

Lumpy,
VR stands for 'variable reluctance'. It consists of a magnet and a coil so therefore it does not require an external power source. Essentiallly a magnetic flux is created and as a ferrous metal target approaches and passes the pole of the sensor an AC voltage is generated which becomes the input pulse for the ECU. I don't know about the engineering ability as I don't have an engineering background. Basically it came about because I read an article in a magazine about a project that involved the conversion of a later model belt drive 900SS from carb to EFI by grafting on a complete system from a later model Ducati. I wanted to go further than this and implement a fully user programable system so I got into some pretty extensive research to learn about engine management and to see what was out there. This led me to 'Microsquirt' because it was completely DIY and affordable.

With regards to how the ignition part works, I am struggling to find a way to briefly summarize it for you. But I'll have a go anyway. Basically everything starts with the crank sensor and trigger wheel. The Microsquirt has a number of user selectable ways of dealing with this input to create the correctly timed ignition events. One is 'dual tach input' which I chose because of the odd firing angle of the Ducati 90 degree V twin engine. I use a multi tooth trigger wheel because it delivers a higher level of timing accuracy as a result of the software using a tooth counting and time prediction algorithm to determine when the next tach input should occur. The missing tooth on the wheel creates a reference point. The tach event occurs on the first tooth after the missing tooth, but this can be shifted to another tooth by using a delaying configuration just in case the wheel's physical mounting position cannot be altered. I have set mine up to provide a tach input on the first tooth after the missing tooth (declared) and this physically occurs at 25 degrees ATDC. After sync this event is assigned to ignition output #1 and injector output #1 which are tied to the rear (timing) cylinder. The tach event for the front cylinder is created by skipping 24 teeth (360 degrees crankshaft rotation) from where the rear cylinder event occurs. Because of the odd firing angle ( front cylinder fires 270 degrees after the rear cylinder) this event has to be offset by the appropriate amount to get correct timing. This event is then applied to ignition output #2 and injector output #2. The ATDC timing happens because the ignition events are setup in advance to allow adequate dwell time and the application of spark advance as determined spark advance table. The hardware and software of the ECU do the rest. The ignition outputs from the ECU are logic level signals containing the user configurable dwell periods and these are cabled directly to the coils which do the rest.

I think that I am finding it much more difficult to put into words a description of what I have done than it actually was to do it.
Here are some screenshots of the tuning software interface and tuning tables that I am using.

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