FI Rigs

[smegballs]

Hi looking at FI conversions for various carbed bikes and I'm considering pikeyish yet innovative methods of installing a homebuilt FI system.

A cheap (I hope) way of doing it I thought of would be to "single carb" to inlet manifold ie make up a manifold from all the cylinders leading to one big intake, perhaps with a small car throttle body on there to regulate airflow. Then just have one big fat injector into this multiple manifold to provide the AF mix.

With regards to control systems this seems to be the tricky part. Now over the years it seems EFI had ranged from very basic fixed maps with no deviation and then has progessively advanced to now have billions of sensors and fully self managing...

As in effect the injector system controls the pulse timing and pulse width it seems possible to jury rig some thing to work..... Say getting an EFI system of a simple bike like a YBR, modding the crank sensor so it would have 4 times as many firing events and a remap to get the the correct pulse width for the injector used.

Just to stress this wouldnt be a swap looking for more power or anything, just a bit of fun and a project just to see if I can get something working.

[stevo as b4]

I wouldn't run a mulit cylinder bike with a Plennum based injection set up or a single point fuel injection system. This set up works okish for cheap and low performance car engine's, but it's still not ideal for throttle response, power, or emissions.

bear in mind that in bike engines as well as car engines that the middle cylinders would probably run hotter than the outer ones, or depending on the shape of the water jacket/ where the inlet/outlet is sited on the block, that different cylinders could need different amounts of fuel ideally. Being able to trim in or out fuel for individual cylinders is very useful in terms of keeping the engine running at it's best efficiancy.

I think that the only way to build a multi cylinder FI system successfully would be to use a set of off the shelf throttle bodies and injectors for an engine size similar to the one you want to fuel inject, and one thats ideally in a similar state of tune.

I would look into Mega squirt as one of the most affordable ECU solutions, and you can buy the ECU's in kit form and ready built now even with a very approximate base map loaded up.

[smegballs]

Thanks for the advice, I can come up with all sorts of ideas in theory, but I admit I haven't the real world experience yet to know if it will be ok in practice.

I'm looking at possibly helping a mate turbo a CB500 as part of a uni project, hence the search into EFI as carbs and turbos dont mix too well.

I looked into MS a while ago and it seemed that there wasn't many people who actually got it to run right. A quick Youtube search shows plenty of things running well so I guess the bugs it had have been taken out.

Another plus I think it using the MegaSpark unit alongside to make a completely programmable ECU.

[hmmmnz]

i did a fuel injection system on a gsxr1250 turbo using the mega squirt system,
it was fairly simple to use and fairly easy to install,
there is a good forum for backup and its easy to add bits to the system.

have a look at that,
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Kickstart]

Hi

Suspect the ECU would be the easy bit. Plenty of aftermarket ECUs, and suspect you could also butcher one of the Triumph systems (which are pretty easy to reprogram with readily available software).

Throttle bodies are the difficult bit, although you can always go the route of chopping up a set of carbs to use as throttle bodies (used to be quite commonly done with Weber or Dellorto carbs on cars).

The most worrying bit would be welding up a fuel return to the tank.

Turbos do work OK with carbs. You just need to seal them, supply them with fuel under enough pressure (and not too much) and vent the float bowls to the plenum chamber. Original Lotus Esprit turbo used a set of sealed Dellorto carbs with a blow through setup.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[smegballs]

[Kickstart]

Hi

Nope, that is a pretty common way to lower the compression. Possibly not the best way as it leaves you with a wide open squish band, but is cheap and easy.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[temeluchus]

https://www.youtube.com/watch?v=E-pqcCAoZok
____________________
Some shite cruiser. Now with guns and FREEDOM!

[smegballs]

[temeluchus]

its a Dnepr MT10-36.

The originals were copies of sidevalve BMWs/Zundapps and evolved over the years.

I was curious about making an FI system for my bike and found it.

I also thought about it on my GSXR1100, I had sourced the throttle bodies and injectors from a GSX1400, but didnt get aorund to it.
____________________
Some shite cruiser. Now with guns and FREEDOM!

[temeluchus]

[smegballs]

For those who have made an effort before.... Do lamda sensors need to be purchased new (expensive) or can they be happily liberated for the cage scrapyard?

[Kickstart]

Hi

Fair chance that the ones in the scrap yard are there because the car failed its MOT on emissions. They are not that expensive new.

However for setting up an engine you would probably want a wide band lambda probe and they are not cheap, nor are they used standard on any cars I can think of.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[hmmmnz]

[robocog]

I'm running MS for fuel and sparks on my kit car (Ford Mondeo engine but using motorbike TB's- R6??)

Wideband Lambda setups can be bought as homebuild kits now, and are surprisingly inexpensive compared to what they used to be

I'm using a JAW wideband controller (14Point7.com) was about £20 to buy and was built in less than 1/2 hr and the Bosch LSU 4.2 sensor was only £30 (eBay) IIRC

The proper plug for the sensor was however a bit pricey and was ordered from Australia as it was the only place I could find selling them

I did originally use a 4 wired narrowband sensor and made a "row of LED's" gauge which was helpful to me getting things running and in the ball park but not very accurate according to the local rolling road when I took it there for a dyno day and they compared the fuelling plots

Narrowband sensors can be had very cheaply on eBay and worth experimenting with, but definately worth getting fuelling checked over by someone with proper test gear if you are loading the engine

Not been back to the rolling road since going wideband. I assume it should be pretty accurate now, maybe not as accurate as their setup (think they said their sensor was £1000 a pop!...I'm in the wrong game)

Have roughly tuned the car using what data my sensor/controller is showing and it seems to be running well enough (keeping slightly rich under load) and havent melted anything yet

MS is a pretty interesting project and theres plenty of documentation out there for it and a well trodden route

It has been a fun project for me and I think I learned quite a lot in the process.

Regards
Rob