Author Topic: Megasquirt on a K75. (DIY fuel injection system)  (Read 59573 times)

Offline fadingfastsd

  • Motobrick Curious
  • Posts: 27
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #50 on: January 21, 2013, 04:54:06 AM »
This is really cool. I've been interested in the Megasquirt system since I considered doing an FI swap on my old carbed 73 Plymouth Duster that was my DD about 3 years ago. I'm kinda toying with doing this on my K100. Keep us posted on this system as you work out the bugs please!
1985 BMW K100
www.racetechelectric.com
High output motorcycle stators, voltage regulators & electronics.

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #51 on: February 25, 2013, 01:54:56 PM »
Its been working pretty well. Still adjusting things (which for me, is the fun part). I added a vacuum manifold, that connects all three throttle bodies , the fuel pressure regulator, and the air pressure sensor. This provides an automatic balancing of the throttle bodies, as well as a more stable, reproducible manifold vacuum signal, which better represents the actual conditions. However, the vacuum is inaccurate at high throttle openings. To compensate, I switched the tuning method to Individual Throttle Body mode (ITB mode), where it utilizes the manifold vacuum at low throttle openings (to about 90% of barometric pressure) and throttle position at higher loads. So far, it is working well. I will post more as I go.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline fadingfastsd

  • Motobrick Curious
  • Posts: 27
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #52 on: February 25, 2013, 03:00:59 PM »
Awesome, thanks for the update. Keep us posted here, this is really cool. How much would you guess you've spent on this conversion so far?
1985 BMW K100
www.racetechelectric.com
High output motorcycle stators, voltage regulators & electronics.

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #53 on: February 25, 2013, 04:02:29 PM »
Awesome, thanks for the update. Keep us posted here, this is really cool. How much would you guess you've spent on this conversion so far?

Probably about 350-400 If I wanted to sell off the original stuff, I could easily pay for it.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #54 on: March 02, 2013, 03:23:32 AM »
I'm really starting to get the tune dialed in. I have great throttle response, and steady AFR's throughout the fuel map. Once its a little more dialed in, I will work on the cold running conditions. In addition, Phil Tobin, the guy who wrote the tuning software, is going to be debuting an auto-tuning algorithm for warmup variables.

On a ride I took this evening, at constant 70 mph, I am getting about 50 mpg instantaneously, with an AFR of 15:1. I still have room to go as it is running smoothly with no misfires, and I can probably dial cruise AFR back to about 15.5-16:1. Something around 55 mpg (US) at 70 mph is definitely achievable, which is quite good for an unfaired (except windshield), undergeared, shaft driven, bag equipped, standard with 100k miles on the clock.

Once I get the cold start tuned, It will be a very feasible and useful upgrade for others. I will have done 95% of the testing, research, work and trial and error involved, and will set up a cohesive set of documentation here once I settle in on a final configuration.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline Lawrence

  • ^ Proficient Motobricker
  • Posts: 301
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #55 on: March 02, 2013, 11:17:57 AM »
That's great! Doubly so because others will stand to benefit from your work.  Well done, my man!  :2thumbup:
1985 K100RS

1982 Laverda Mirage 1200TS
1983 BMW R100RS

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 3653
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #56 on: March 02, 2013, 12:00:07 PM »
Awesome contribution on your part.  Five motobirds!

 :mbird :mbird :mbird :mbird :mbird
93 K11LT
94 K11RS- "Kato"
86-97 K75F (K75/100/1100 Frankenbrick)
86 K75C w/ paralever, high perf. cams,TURBO!
91 K1
86 custom K100
and 2 more
IBA #17739 (SS1K, BBG, 50CC)

Buy parts HERE

Offline fadingfastsd

  • Motobrick Curious
  • Posts: 27
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #57 on: March 02, 2013, 03:30:43 PM »
This is so cool, I'm really stoked to hear about your progress. I'm really thinking about doing this on my K100. I'd love to see all the documentation and info you put together on this.
1985 BMW K100
www.racetechelectric.com
High output motorcycle stators, voltage regulators & electronics.

Offline sweatmark

  • Curious
  • Posts: 4
Re: Megasquirt on a K75
« Reply #58 on: March 16, 2013, 02:19:58 PM »
Good topic. Im new here. My intended projeKt would use mega/microsquirt to replace L-Jetronic, though I'm fond of the analog air-flap meter's steam-punk-ish-ness.

Thanks for posting the info and experience.

Mark
Oregon
Now: 2004 R1150R Rockster, 2007 F800S
Then: R850R, R1100R, R1150R, R1200C, Buell, crotch rockets
Mark
Oregon
______
Now: 2004 R1150R Rockster, 2007 F800S
Then: R850R, R1100R, R1150R, R1200C, Buell, crotch rockets

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #59 on: March 19, 2013, 09:36:38 PM »
I will be switching my bike over to microsquirt (Module). I am helping my friend megasquirt him and his dad's '68 camaro, and he is swapping my megasquirt for a microsquirt module. I will be able to fit the whole assembly into a project box, and clean up a lot of the wiring, with a smaller package for the whole thing.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline pdg

  • ^ Proficient Motobricker
  • Posts: 290
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #60 on: March 20, 2013, 03:22:51 PM »
Was just wondering what sort of average/overal MPG you managed to get with the megasquirt?
1988 K75S

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #61 on: March 20, 2013, 08:13:24 PM »
Was just wondering what sort of average/overal MPG you managed to get with the megasquirt?

Still working on that, as I haven't had a chance to take a long ride yet, without warmups and tuning. Currently, its about the same or a little lower than as previous, but that is with more aggressive application of throttle/brakes, and sitting warmup. I am close to getting the warmup curve tuned, so I should be able to ride while warming it up, which should reduce fuel use a lot.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #62 on: April 03, 2013, 08:04:52 PM »
Almost done with the microsquirt box. Will post pics when it is done. Quite proud of the design of the ancillary components, managed to cram the microsquirt module, wideband controller, bluetooth, a 15 amp relay,  and a breakout board with screw terminals for everything into a 4x7x2 box.

I may also set up the microsquirt to control ignition as well. I can add the 3 or so degrees at higher rpm, and keep it retarded for smoother running at low rpm.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline Brad-Man

  • ^ Proficient Motobricker
  • Posts: 358
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #63 on: April 04, 2013, 01:50:47 PM »
I would think that you would want more advance @ lower rpms and then retard @ higher....


BTW - I am MegaSquirting my '83 280 ZXT after putting on a larger turbo than the upgraded one I currently have and adding an intercooler, so am very interested in doing this to my '85 K100 too.

I have already purchased everything but shock for paralever suspension and have purchased 4v forks & front end minus rotors and wheels.

I have too many projects...

Really digging the info!
  • Marietta, GA
  • '85 K100
Toys don't make the Man - Man makes the Toys...
'74 RD350
'75 RD350 w/Modified 400 engine, Chambers & MZB iggy

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #64 on: April 22, 2013, 04:45:38 AM »
I finally had some time to put some more together. Got it 90% wired in this evening. This is the box, with all components. Includes the wideband controller, bluetooth, and a 15 amp relay.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #65 on: April 25, 2013, 05:41:29 AM »
Gotta do a couple changes. The Wideband O2 controller (bottom Left) draws too much power from the 5v rail of the microsquirt module (top Left) so the Voltage regulator is heating up. So now I need to do a little re-wiring to take the power from a separate voltage regulator on the bluetooth interface board (Bottom right).

Unfortunately, all of it has to wait a while, as school is taking up too much time.  :deal:
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #66 on: May 06, 2013, 02:50:46 AM »
I got a bit of time today, and put the last bit together. Had to make a circuit with a pullup resistor and a diode to supply a clean ignition signal.
  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline keith g

  • Motobrick Curious
  • Posts: 27
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #67 on: May 18, 2013, 04:20:36 AM »
i love what yer doing..........just wish i understood it.....:)
  • UK
  • 1985 K75c

Offline wmax351

  • ^ Quintessential Motobricker
  • Posts: 1218
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #68 on: March 11, 2014, 12:39:58 AM »
Next steps in this project: I'm going to add ignition control and use a MAF sensor, and switch the wiring board to a custom printed circuit with built in bluetooth and wideband oxygen sensor control.


This will require a custom crank sensor, closer to the type on a car. I will base mine on the one from BSK speedworks (image 1), but with a hall sensor instead of a VR sensor, and a 3d printed housing.



  • Ann Arbor, MI
  • 1991 BMW K75 Standard, Refreshed '94 engine
Bikes:
Current:
1991 BMW K75 Standard, Refreshed '94 engine


Past:
'83 BMW R65LS (An R65 with a prototype K Bike Front End)
'75 Honda CB550F
'69 Honda CB175
1999 Royal Enfield Bullet 500 (Last month of the original '55 model)
1973 Triumph Tiger TR7V (5 speed, Right Shift, Disc Brake)
1971 BMW R75/5 in Toaster outfit
1979 Harley Davidson XLS-1000 Sportster Roadster

Offline pdg

  • ^ Proficient Motobricker
  • Posts: 290
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #69 on: March 18, 2014, 11:30:27 AM »
I would think that you would want more advance @ lower rpms and then retard @ higher....

In keeping with my noticing things many months after they are said...

The lower the RPM the less advance you need for an engine to run smoothly, in fact a lot require the ignition to be retarded ATDC otherwise you get pinking and in some cases stalling and 'popping back' through the inlet.

As the speed increases you require more ignition advance so the burn happens at the right time and pushes the piston down (well, ok, across in a k-block, whatever, toward the crank) - if you retard the ignition at higher RPM all you get is less power as the bulk of the burn is happening when the piston is getting toward the bottom of the stroke, or to be extreme, after BDC and when the piston is heading back up - burnt valves and flamey exhausts ahoy.

In a mechanical distributor system you generally have 2 forms of advance/retard system - centrifugal and vacuum controlled. Both of these - within different speed ranges with some crossover - retard (or leave where it is statically set) the ignition spark at idle and then advance it as the speed increases.

The only time you would want to retard the ignition at higher speed is as a rev-limiter - because it would be 'hit' so rarely in normal use the valve burning isn't a concern.
1988 K75S

Offline lmiklosy

  • One Less Car
  • ^ Motobrick Curious
  • Posts: 67
  • Bike ON!
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #70 on: November 29, 2017, 02:34:12 PM »
Greetings. Say you want to record some mundane systems data from the Jetronic or Bosch ABS like coolant temperature, engine RPM, gear selection, wheel speed. Do the vendors or BMW publish specs and an API for this purpose?  Protection from liability tells me NO, but I figure this thread is the place to ask, there are only two hits for "datalogger" at Motobrick.
  • Laguna Beach, CA
  • 1993 K75S-Mystic, 1981 R100RS-RedBaron, 1991 K75S-Marrakesh

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 1941
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #71 on: November 29, 2017, 07:15:22 PM »
Jetronic and Motronic are mostly analogue in nature, so no API or digital interface.  You'd have to design a device to interface into the ECU and ICU to create a datalogger.  There was a device called U-Diag that was a synchronization and diagnostic tool, but it is no longer available.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline lmiklosy

  • One Less Car
  • ^ Motobrick Curious
  • Posts: 67
  • Bike ON!
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #72 on: November 30, 2017, 12:10:40 AM »
Digital interface silly me. Wonder how BMW does stability control?     Thanks rbm.
  • Laguna Beach, CA
  • 1993 K75S-Mystic, 1981 R100RS-RedBaron, 1991 K75S-Marrakesh

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 1941
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #73 on: November 30, 2017, 05:21:50 AM »
Read about it in the Bosch L-jetronic Technica Manual.

P.S. Haven't yet found the BMW Fidget Spinner gyro-stabilizer in my K75; guess I'll have to open the ECU and look. :hehehe
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline lmiklosy

  • One Less Car
  • ^ Motobrick Curious
  • Posts: 67
  • Bike ON!
Re: Megasquirt on a K75. (DIY fuel injection system)
« Reply #74 on: November 30, 2017, 12:10:39 PM »
Thanks for the manual, great place for me to start.  Meat of it starts on page 19, there must be a diagnostic port on the ECU to tap signals, I'll find it.   

There should be three spinners in your ECU, look for X, Y and Z.  :yes
  • Laguna Beach, CA
  • 1993 K75S-Mystic, 1981 R100RS-RedBaron, 1991 K75S-Marrakesh

Tags: