WHAT ECU and Inputs for the Muti Air
My ( unworthy ) 2 cents
Whilst the thread was Fiat SOHC vs K20 in the OP's question, to me it is about ease of fitment. I totally understand why in North America the K20 is popular as available suitable power-trains are thin on the round. For me when power train that fits the engine compartment without cutting and shutting is available I take the 'easy' route and play the aftermarket engine management. Ones and zeros are befuddling at times but once achieved the knowledge can be shared.
In one of my X's has lived the original 1300 a 1500 SOHC X1/9. A Uno Turbo Mark One a Uno Turbo Mark Two and Punto Gt Turbo engines saw a transition to aftermarket ECU. Some of these engines were sourced here Downunder some from New Zeland and the UK, one which was a bargain Punto GT 8v Turbo crate motor that 'fell' into my hands. The Australian Wolf 3d V4 that I use is by no means a premium ECU anymore but mapping the engines that have occupied my X's engine bay is not a biggie as the base maps are variations on what had gone before, time on a dyno has been more of an expense. Stochiometric AFR's are a well documented table but optimizing them has been 'ínteresting' hobby, my greed for max boost on ethanol based fuel is my stupid problem when - you get lean condition at high levels of boost the bleeding edge of death is often counted in seconds. Hence my stupidity - but Mmeehhh it's a hobby and I like to learn as I am no mechanic.
The very fact that what is written in the above posts is so true is the very reason why Muli Air Fiat 500 engines are nearly worth scrap Downunder from what I have been tracking at scrap tards / wreckers.
As low as $700 AUD will get you a low milage 'long motor' as no one knows what to do with them besides fit them to existing 500's. A living example of what 'Coupfan' said is the VAG guru that looks after our VW's. A god Audi / VW / Porsche specialist even he tore out the entire electrical 'intestinal tract' of a current model VW Polo GTi roll over wreck to fit to a series one Type86 Polo from the 1980's because of what Matt correctly stated CANBUS is EVERYWHERE now. The current model wreck was mechanically intact but the direct shift gearbox and motor were so complex that it was easier to unstitch the 'power-train wiring harness' from the rest of the loom. Things like the LH rear wheel speed sensor being adapted to the old Polo rear suspension to make the ECU work were easier than trying to find an aftermarket engine management computer to mimic the vast amount of inputs. Let alone how much one of these computers with required sensors and emulators costs to adapt, besides this was a pet project for Jim and time was no object, $ were.
Despite this above example I am still curious about the Multi Air ( especially the Abarth ) so have watched the Oz Eastern Seaboard auctions and how little a total chassis write off goes for.
To my mind rather than saying 'nnaaaar' too hard I ask 'what inputs does a manual Muli Air actually need to function'. There must be an ECU that has enough in / outputs that can make sense of what the
power-train as a whole unit requires to function, but we will be talking over the thousand $ plus region for just the ECU and the sensors as you are targeting the same level ECU that is in a serious race car.
So if a low mileage power-train goes for so little as no one has 'nutted out' the way to make it work in anything but a Fiat 500 the funds that are often demanded by a 'popular power-train' could be channeled to a suitably complex ECU and the sensors / dummy emulators. For those that are willing it would not be a cheap exercise. How that could translate into a Megasquirt project once the 'test bunnnies' have worked out the requirements. The Megasquirt project Mathew posted on here probably started the same way, but this is a notch up the electronics ladder - Can it be done ? I don't know enough about the Megasquirt to know if it is scaleable enough to expand to the complexity required.
Someone like Robert Tallini wouldn't be interested in spending time on this as I'm sure people like him are busy enough with his market segment, if the X 1/9 Mulitair became more than a oddity perhaps expertise and knowledge such as his could be accessible. With their packages after 4 grand they çome on the pipe' strongly. Is 240 Hp at 25 pounds of boost something that interests you? That the Dodge Dart the 500 and the Alfa Mito etc use this engine is an opportunity that provides a huge scope of adaption to the X1/9, could it be comparable to the aftermarket of the K20 world?
To not get into a discussion about whether it's a good or bad idea perhaps channel the brains trust into what the Multi Air needs to (fully) function, that turned into a meaningful list will be the real determining factor. Many heads can make light work of this complex electronic control subject. A power-train from a Fiat 500 Abarth esseesse (SS) six-speed manual with a Q2 Torsen C limited slip differential is a desirable package.
End result will be a decent manual gearbox (I admit the 5 speed CW&P is glass) and modern breathing powerful small 4 cylinder that fits the engine bay without massive amounts of body modifications. That to me is a worthy goal - not whether it is Italian in origin, in today's world Engine development is often shared - try and tell a 'new' mini owner his engine is from Peugeot in France. One of my dream cars is a Pantera and the American Muscle engine in that is an asset with the factory evolution and development that it received over the years.
Hence I have started a thread (
Over Here ) please discuss how the Muli Air works and lets spend our time on 'what makes it tick' rather than one power-train solution over another. Whilst the K20 makes total sense in North America it makes less sense elsewhere. With the number of Fiat 500's that you guys have in your market it is a complex problem that a excellent forum like this can in most likelihood solve, then the K20 will make even less sense. The end result could be a trans-axle and motor that fits without cutting the body and could be an attractive solution to a dead motor/gearbox or power upgrade to modern reliability.
A worthy intellectual pursuit for our 'mass produced' go cart with a tag plate.
