EFI conversion on a Gen-1

[MaxMidnight]

The reason for the vboost was surely to give the good low end of small carbs (and they are small), combined with the top end airflow to give the v4 what it needed. With adequately sized TBs you won't need the vboost?

I think that is a very interesting question - I agree with your summary on V Boost and that with large throttle bodies and F.I. the requirement for it should not be there.

However, a couple of thought occur; at low revs the air speed will be low and whilst this is not an issue for atomising the fuel, will the spray from the injectors be carried into the cylinder or will it drop out onto the walls of the inlet? I also wonder if the inertia of the airflow (i.e. at low revs will it have to be accelerated to match piston speed?) might affect how much charge will make it into the cylinder?
My other thought is how much turbulence will the step down sleeves introduce into the airflow and what effect this will have?

I'm no expert of F.I. so please excuse this layman's ponderings.

 

[huw s]

I think that is a very interesting question - I agree with your summary on V Boost and that with large throttle bodies and F.I. the requirement for it should not be there.

However, a couple of thought occur; at low revs the air speed will be low and whilst this is not an issue for atomising the fuel, will the spray from the injectors be carried into the cylinder or will it drop out onto the walls of the inlet? I also wonder if the inertia of the airflow (i.e. at low revs will it have to be accelerated to match piston speed?) might affect how much charge will make it into the cylinder?
My other thought is how much turbulence will the step down sleeves introduce into the airflow and what effect this will have?

I'm no expert of F.I. so please excuse this layman's ponderings.

You might be right, in that keeping the airflow high is just as important,with FI. Indeed, many car designers have the variable intake valves for just this reason. So ideal throttle bodies would retain the mikuni size butterfly and bore then? Makes sense to me.

 

[MaxMidnight]

So ideal throttle bodies would retain the Mikuni size butterfly and bore then?

Probably not as I suspect you would have the same issues as with the carbs not being able to flow sufficient air at higher revs which brings us back to V Boost...DOH!

 

[02GF74]

Probably not as I suspect you would have the same issues as with the carbs not being able to flow sufficient air at higher revs which brings us back to V Boost...DOH!

I'm looking into whether oversize TBs have a detrimental effect but since presumably the Honda VFR 1200 runs ok at low RPM/power it must be possible - maybe Honda has some tricks we are not aware of.... hence why I suggested using the Vboost and firing a second injector.

Som info.:
As a general rule of thumb a large bore results in lower flow resistance, a small bore results in better throttle response and more precise air/fuel ratio mix. There are a few guidelines to be followed when selecting bore size and assumed BHP/cylinder using an assumed rev range up to 9000rpm.

BHP Millimeters
35 40
40 42
45 45
55 48
65 50

With carbs, the Venturi effect ensures fuel is being added when needed, with injectors it`s up to you to make sure the timing is right. That means you might end up in a Vboost situation where one cylinder gets too much fuel, and the other is starved which can overheat that cylinder and cause extensive damage!. I would only attempt that if you have a Wideband Lambda on all cylinders.

The way I envisage this working is that the FI for the main cylinder will be maxxed by the the time the vboost servo valve starts to open, so the FI for the secondary cylinder will start to contribute - the additional amount of fuel will be based on RPM and vboost valve position (via the servo potentiometer). As the engine goes through its cycles, the amount of fuel injected will change as the main and secondary cylinders swap round.

I may have not explained it well but it is not a case that one cylinder gets the incremental amount of fuel and other gets max, the amounts swap between the two cylinders.

 

[02GF74]

I'm stepping away from this until the OP does an update or two. We may be discussing a problem that may not be there.

Re. the stepped adapters aren't optimum but should get the engine running, again let's wait until then.

 

[RempageR1]

Hi,

I loved the discussion and perhaps a second set of injectors might help. I`m not sure though my injectors will max out. They do 315cc/min at 50 psi, which provides the following theoretical power:

So you might still be able to use just the original injectors. Anyway, I am planning on removing the Vboost but if anyone feels like giving it a go, please let me know how it worked out .

And yes I agree the reducers aren't optimal but they should be able to make the bike go for now. If I can get everything working I`ll have a look on how to enlarge them.

Also, the VFR1200 doesn't seem to have any EXUP-like valve in the exhaust to increase the torque nor anything special in the airbox (which I have here also, more on that at some other time). So the only difference between the VMAX and the VFR1200 might be inlet/exhaust ports/valves. Stroke and bore are also quite similar.

In the mean time, I was busy fixing the TPS based on your remarks, so that`s why it`s been a while. Basically, I repositioned the TPS to another TB so it now sits behind the mounting plate. Also the way it`s fixed now prohibits the little L-shaped piece to slip:


A small screw and washer was installed on top of the plate, not shown in the picture below:



So another possible issue resolved!

Also I reduced the size of the Speeduino housing so it fits behind the left fake airscoop:



That`s all for now

 

[RempageR1]

Lots of small things have been done, but the most important one was the exhaust. First, I needed to know where to place the O2 sensor and I was lucky enough someone had an old exhaust that I was allowed to cut open. So if anyone wondered: There`s nothing there



To make the O2 sensor fit, it needed to be in the center of the exhaust, and should go underneath the rear swingarm central tube and the frame. To make sure the bung wouldn't warp, I needed something with the same threat, which was the rear axle



And the final result:


Nice isn't it? . Next up: Modifying the tank!

 

[hogfiddles]

Keep going !!

 

[gentsvmax]

I have decided and would like to order now

 

[one2dmax]

Nice progress still

 

[RempageR1]

So, as promised, here is the tank update .
Since an injection system requires fuel to be continuously flowing, a return pipe needed to be added to the fuel tank. The first idea was to add a bulkhead fitting and some hose to my original tank, unfortunately after removing the tank, I found out it was leaking around the lower mounting bracket. As a result, I decided to ditch that tank with the exception of the fuel line:


The idea was to reuse that one and mount it to the bottom of the tank. For that, the bush and brace were created as shown on the picture. By soldering it up top and adding the brace, it would be sit nicely in the tank. The problem however was how to get the bush mounted to the bottom of the tank without having to cut it open. After going through a lot of options, I decided to mount it to the fuel drain hole of the tank. Here`s how I did that:

Step 1: Push something through the bottom hole and out the tank as shown


Step 2: Replace it with some wire

Step 3: Create something like below that can fit through the bottom hole and can be turned (screwed in) from the outside. Also add a bit of wire to the other site so you can align it with the hole.

Step 4: Feed it through and screw it into place:

Step 5: Add a nut and ring

Step 6: Saw off the remaining bits and you`re done .

Finally, the fuel line was fed through from the top and was soldered on:



After that, the tank was sealed using epoxy and was painted on the outside. So now it`s ready to be connected to the fuel return line from the regulator.

Next up: Finishing up the electronics for test driving with the carbs still on.

 

[RempageR1]

Another update: I was able to get the bike running with the carbs, but with the Speeduino attached as well. It`s at this phase only there to validate the electronics and ensure we get valid signals from the bike. The first thing I did, was to create a reading from the pickups. Since I run the Ignitech for ignition and want to keep it for now, I cannot change it`s wiring. As a result, I tap into the current wiring and send the same pick-up signal to the Ignitech and Speeduino. (Green wires go to Speeduino).

As you can see, the Ignitech connects two pick-ups to one input, and the same was done for the other two. So four pick-ups end up in two inputs.
For the Speeduino, I used the cam and crank inputs and got this signal:


So you can see the way the pick-ups are connected. One signal is the left two cylinders, and the other signal is the right two cylinders. The first pulses (green and blue) are 180 degrees apart (2 cylinders use the same crank pin), and the second pulses are 70 degrees after the first ones since it`s a 70 degree V-4.

Using that signal, I recreated the same signal on the Ardustim as you can see here on the left:



With the signal being simulated with Ardustim, I found out no decoder was available that could handle my inputs so the ignitions were random and RPM`s were all over the place. After days of work, I created my own decoder source that can trigger on the four pick-ups from the Vmax and can even cope (somewhat) with a pick-up being broken. After the work, the led`s now show the ignition and injection without any flickering (which points towards an issue with the timing). Doing this would have been impossible without the Ardustim, so I cannot emphasize enough on buying one to validate your setup.

If anyone wants to have some fun with the Speeduino and has the four-pickup version of the max, you could use the code attached and then select 'Basic distributor' in the tuner studio. This is arduino source-code against the 202103 source-code.

In theory, you could also use the signal towards the spark coil of cylinder 1, but that would cause a delay in starting (first the ignition system needs to sync on the crank signal, and then the injection module needs to sync on the ignition signal). Also, the ignition signal timing changes over rev`s and engine load. Finally, you only get 1 signal every 360 degrees on the crank, while I get four signals every 360.... So time well spent

 

[02GF74]

It's been over a month, any progress?

 

[Big"A"]

Another update: I was able to get the bike running with the carbs, but with the Speeduino attached as well. It`s at this phase only there to validate the electronics and ensure we get valid signals from the bike. The first thing I did, was to create a reading from the pickups. Since I run the Ignitech for ignition and want to keep it for now, I cannot change it`s wiring. As a result, I tap into the current wiring and send the same pick-up signal to the Ignitech and Speeduino. (Green wires go to Speeduino).
View attachment 75905
As you can see, the Ignitech connects two pick-ups to one input, and the same was done for the other two. So four pick-ups end up in two inputs.
For the Speeduino, I used the cam and crank inputs and got this signal:
View attachment 75904

So you can see the way the pick-ups are connected. One signal is the left two cylinders, and the other signal is the right two cylinders. The first pulses (green and blue) are 180 degrees apart (2 cylinders use the same crank pin), and the second pulses are 70 degrees after the first ones since it`s a 70 degree V-4.

Using that signal, I recreated the same signal on the Ardustim as you can see here on the left:

View attachment 75906

With the signal being simulated with Ardustim, I found out no decoder was available that could handle my inputs so the ignitions were random and RPM`s were all over the place. After days of work, I created my own decoder source that can trigger on the four pick-ups from the Vmax and can even cope (somewhat) with a pick-up being broken. After the work, the led`s now show the ignition and injection without any flickering (which points towards an issue with the timing). Doing this would have been impossible without the Ardustim, so I cannot emphasize enough on buying one to validate your setup.

If anyone wants to have some fun with the Speeduino and has the four-pickup version of the max, you could use the code attached and then select 'Basic distributor' in the tuner studio. This is arduino source-code against the 202103 source-code.

In theory, you could also use the signal towards the spark coil of cylinder 1, but that would cause a delay in starting (first the ignition system needs to sync on the crank signal, and then the injection module needs to sync on the ignition signal). Also, the ignition signal timing changes over rev`s and engine load. Finally, you only get 1 signal every 360 degrees on the crank, while I get four signals every 360.... So time well spent

Know of anyone using a megasquirt 2

 

[RempageR1]

Hi, yes there has been progress. I have to admit it`s slow but that isn't due to a lack of trying. Over the last months I found out that having a working setup on the bench is something totally different than having one on the bike .

First of all, here`s a low-res video of what the dash looks like:

View attachment 1.MP4


























And this is what the dash looks like. This is RealDash for IOS, which connects to the Speeduino via Wifi:


That app can also do data logging, and I have spent lots of time getting the crank signal absolutely perfect. If it isn't, the telemetry looks something like this:




While it should look like this:


The blue line is the RPM, the Green one there is the throttle position. The 'heartbeats' you see in the blue lines are the slack in the drive train, where the engine goes from delivering power to the rear wheel, to it being driven BY the rear wheel. It took me a while to figure that out
Getting this stuff absolutely perfect is VITAL to getting the Injection running correctly. So with the carbs on the bike, you have the opportunity to get all the bugs out.... which took me a while....

One of the reasons I had troubles with syncing was the crappy original wiring of the Vmax. The picture below shows a ignition coil being charged and firing. That drops the voltage by 2V! Incredible that the bike has no issues with what noise. Injectors however like a stable voltage, so for that I need to add a relay and direct 12V from the battery (via a fuse).


Also fun: This is the noise generated by the O2 controller:


That also makes the voltage go down 1V.

In the end, I used the VR-conditioner by Speeduino and DID NOT connect the VR-. (Relevant info for anyone wanting to repeat this).

So now I got all the electronics working: Throttle position, O2 sensor, Temp sensor, MAP sensor, Crank sensor, and Voltage. Since it all (finally) works as it should, I can now start to focus on the hardware side of things.

The throttle bodies cannot work with the VFR1200 air filter, so I removed the mating surface for that and added rings. Picture before:


And after:


So it now takes the Vmax airfilter as well. There was the small air induction bypass that I blocked as shown in the picture and drilled a tiny hole on the inside of the throttle body to keep the air induction system operational.

The last missing piece was the fuel rail tubing. A friend of mine created these out of Polyoxymethylene:



Yesterday, I test fitted it and it was perfect! So one of those to go and I have all the parts required and can start building the fuel system.

To be continued!

 

[Parminio]

Wow. Just wow, man.

 

[RempageR1]

Hi!

Again, I have something to share

I`ve done losts of work to get the entire system running. First here`s a pic of the fuel pump. The tape is to protect the bike against the abrasive fuel lines. Not really liking it right now, so I will redo the fuel lines in a nicer way.


This is the position of the fuel pressure regulator. I`m not entirely trusting this one so it will be replaced with something nicer and smaller after testing.


What I am proud of is the way the throttle bodies turned out. It`s a plug and play swap with the carburetors. An a lot lighter!






Like mentioned in the first posts, the TPS wasn't looking all that nice. It now sits on it`s own plate and works just fine!


Another fun one is the amount of room available. It`s such a snug fit with the fuel rails installed!




And finally, the moment I`ve been waiting for, for a LONG time . This evening, I had all the parts installed and gave it a go:



Next up: Tuning!

 

[D Larson]

You have come a long way.

When will the kits be for sale?

 

[02GF74]

Looks like you're almost done.

Not sure braided hoses are required, regular hose will take the pressure and not having outer braiding can be bent into a tighter radius. Also depending on the quality of the braided hose, they can fail and it becomes quite difficult to trace the leak ad the petrol runs through the braid (I had this happen on my land rover and junk all the braised hoses)

 

[Fire-medic]

Research continues!



From XB-51 The Best American Plane to Never Fight
Powered by two GE J-47 turbojets under the wings, next-to the wing roots of the 35 degree swept-wing design of 1945, and a third in the rear of the 85 ft fuselage, pretty-extreme for the time. The USA's first three engine light bomber.


A bolt-on swap-in EFI will make a lot of people excited, but their enthusiasm will likely be damped by the cost of entry. Heck, I'm interested in the progress, but when the cost of admission is probably more-than the cost of many individual members of my fleet, it's sticker-shock.