Hello fellow NSR geeks,

Being an Electrical Engineering student and geek in general I have been thinking about how I might go about making a custom engine management unit for an NSR. So I suppose my question is, has anyone here tried to do this? I think I remember reading somewhere that Matt@TYGA has done something similar.

The whole HRC card thing for the 28 is cool but it would be much better to use a fully programmable unit which would allow for adjustment of advance mapping, RC valve actuation, rev cut, etc. Data logging would be cool too...

Cheers
Tom

Someone else has thought about doing this before, the easiest way to do this would be to buy a programmable system (like Zeeltronics), and have a base mapping to work from. It's long a tedious work trying to get a good map designed up, and potentially costly as you may seize a few times a long the way.

The other way you can do it (I've been thinking about this way) is to fuel inject the thing. You pick up something like the microsquirt and again you need a base mapping to start from.

With a programmable ECU you need a base map for (at the very least) ignition and RC valve timing. Start with 2D, progress to 3D (TPS) when you know what you're doing.

You need to consider that even the ancient PGMIII knew not only how much, but also how fast you were opening the throttle and adjusted the ignition timing to suit. Then there's air solenoid operation vis a vis rpm and throttle position.

On the flip side, the PGMII F3 and NF5 units didn't care about throttle position and relied on a 2D map for ignition and RC valve.

I started with a 2D map based on the NF5. Biggest gains were made getting the RC valve timing right. Ignition timing helped get me some over rev and a little in the mid range. Not a lot to be gained at peak.

Concerning FI. I'm a little skeptical that unless you redesigned the whole engine to direct FI, I don't think you'd get any major gains in performance over a well set up carb. Might save some fuel, or even save the planet, but as for getting to the chippy before me.......I don't think so!

Hi Matt

Thanks for your post. Regarding the control of the RC valve by a PGMIII or PGMIV unit, are there stages to it's opening, or is it simply open or closed? Just by watching it while free revving the engine, it appears to be either open or closed, so I thought there would be some gains to be made with a valve which opens in multiple stages vs, engine speed, and TPS.

As for the air solenoids, this is something which still mystifies me! Can someone explain exactly was it is these things do? Are they a vacuum meter so the computer has another way of gauging engine load?

Cheers
Tom

The RC valve is controlled 3D by both PGMIII & IV. But there are still gains to be made by opening and closing at different rpm values.

The air solenoids bleed air into the emulsion tubes at specific rpm and throttle position.

As to whether the air solenoids are absolutely necessary or not would be a good discussion point. The F3 & NF5 don't have them so why would the NSR need them? However, they do add another variable to help tune the jetting at various rpm points, which is probably a good thing for a street bike that's used through it's full rpm range.

Yamaha use them on the 3MA & 3XV to pass emissions (as far as the info I got says).

To measure the ignition timing, RC valve timing, solenoid timing you need to build some test equipment and then map it all. My test stuff is mechanical as I'm not an electronics whizz. I have a box that mimics the flywheel, controlled by a fan motor. I built a motor speed controller using a schematic found on the net so I can adjust flywheel speeds from about 500rpm up to 13,000rpm. This uses NSR pickups which then just plug directly into the NSR harness.

It works pretty well. Had a bit of a scare with the first flywheel box I made. It was a shade out of balance and exploded @ 12,000rpm

Interesting to hear what you've been up to Matt...

Now call me crazy but has anyone attempted to convert an NSR to a fuel injection system? I know that a well setup carb will have any bike, car, whatever running well but nothing beats the controllability of a full closed loop control system that fuel injeciton can offer!

Have any of the manufacturers produced a fuel injected two stroke before? And why is it so unheard of for a two stroke to have fuel injection?

Major_Tom wrote:Have any of the manufacturers produced a fuel injected two stroke before? And why is it so unheard of for a two stroke to have fuel injection?

Ask Bimota their views on FI strokers

Some Jap dude fitted FI to an NSR. There was a vid of it running somewhere on the net.

Been talking with some blokes recently about direct injection. If there is a way forward for strokers then this is it.

There is the Aprilia SR50 ditech, that was a fuel injected 50cc scooter.

There is a guy in Germany who has used microsquirt to FI his Aprilia RS125.

There is another guy who has microsquirted an RD350. The only benefit he got out of that was a smoother throttle response.

I was chatting to Mick at Total Traction at the weekend and he was showing me the Zeeltronics unit he'd put on an RGV250 with billet power valves. He says he's got a much cleaner mid-range and 60bhp from a stock engine

I had a look at their website Zeeltronics.com but no details on NSR kits
_________________
Why do things simply when you can complicate them

Ignitech also offers some good fully programable units

Never tried one though,i've just heard some good words for their products.

I'm showing one of my lecturers my 28 this Friday, so maybe I can convince him to let me do a project this summer developing a custom PGM unit. At the very least I would like to take an NSR into the lab and map out the characteristics of the unit.

I'm just wondering why nobody as yet hasn't rigged and Ignitech or Zelltronic to the NSR?

Because we've all been happy with Mr Honda's system and haven't thought about trying to squeeze more out of it.

One of these days I will extract out what Honda have set up and use that as a base line.

I used their stuff on my NC30, so when my pgm died i gave them a ring. They say they do not offer anything for the MC21, this was 2 month old conversation.