[ATOMonkey]

Can you mount the IAT in the air box?

Congrats on getting this thing up and going!!

[TheSteve]

Well 2 cylinder mode seems to work as planned, but the engine wont idle anymore. Looks like a complete retune will be needed. Have to work tonight, so it'll have to wait.

[TheSteve]

While I was dicking around on the internet at work, I stumbled across this: http://www.genericse.com/projects_gsx600.php

Turboed Katana, running MS and the same throttle bodies. At least now I know someone can get these to start reliably with MS. I didn't notice a whole lot of interest other than his ignition input and how he mounted his oil temp sensor. For the ignition input, the megasquirt manuals all say NOT to trigger the ignition input from a CDI type coil. This guy seems to have his running well though, and having it set up as a 2 cyl with that trigger is MUCH better than using the HEI and signal generator while MS runs it as an 8 cyl motor. I went through and played with the numbers a little and having it set as a 2 cyl more than triples the resolution of the injection pulsewidths. This might be the key to getting it to start (along with the temp sensor). Right now the crank pulse width is 1.8ms (milliseconds), but about 1.0ms of that is the injector opening time (latency between powering and injecting gas) leaving an actual pulsewidth of .8ms. This means the next step down is .7, and up is .9. This doesn't seem like much, but with MS handling cranking as it does its actually a huge gap. This is 8cyl mode, so it fires each cyl twice per cycle. In 2 cyl mode, firing once per cycle the ideal CPW is closer to 2.7 I think it was. Now the same opening time is present, so real pulsewidth is closer to 1.7. So now the next steps up and down are 1.6 and 1.8, but only firing half as often. Since it fires half as often I can now go much much lower AND much higher in total injected fuel amounts while cranking. This added resolution should give it the control to get a first crank start when the pulsewidth is set correctly. Before, it could get kinda close, but not anywhere near close enough to fire on the first crank. It would crank for awhile and eventually catch (or not). Coupling this with the temp sensor should make this project feasible. The whole reason that I've been putting the sensor off is because even adjusting the pulsewidths wouldn't get me close enough; thats now changed.

The added benefit is no HEI module, even on the 2.2 board. Yay, I did those input circuit mods for nothing. Hopefully itll work without needing to be rebuilt. I'll rewire the input either tonight or tomorrow and see what happens. It'll probably need a retune though. Speaking of which, last tank I only got about 35MPG, but that included ALL tuning and troubleshooting from the very beginning and of course a new riders tendancy to be heavy on the throttle...

EDIT: Oh yeah, I think I fixed the stallout issue. I'll give it a couple days to prove me wrong before detailing the fix.

[TheSteve]

For now the IAT is ziptied to the frame about 3 inches from the motor. The GSXR stuff has a fast idle cam but I didnt have the solenoid to engage it, so I'm fully relying on the idle screw. I set it with the bike warm, but not in its "overheat" mode. If I set it while its trying to shut off it'll probably idle around 3000 rpm normally.. I'm gona play around with it today and see what I can do

[ATOMonkey]

Hmmmm... That sucks that you don't have a seperate strategy for idle. Moving the IAT could definitely help there. It sounds like the MS is just leaning out the mix until it dies. Where do you have the IAT mounted now?

How are you setting throttle idle position? Are you setting it with the IAC inactive, with the bike warm?

[TheSteve]

Thats a good point, I didn't really think about the rubber melting. I'll have to check. I'm not sure MS really uses much of a logic based idle control thats any different than normal operation. It can control fast idle valves and the like, but at idle it doesnt rely on an idle switch or anything. It still just references the VE table for fueling to figure out how much fuel is needed for the RPM and load, then factors in the air temp to determine air density. I turned off O2 correction below 2000 rpm to eliminate almost all decision making on the MS's part to try and diagnose the problem. My only guess is maybe the air temp sensor is getting heat soaked and causing it to believe the air has little density so it slows down fuel delivery but I don't think its getting hot enough to completely kill the motor. The log does show the IAT sensor continually getting hotter as time goes by, even while moving. Maybe it needs to be relocated farther away from the engine.

[ATOMonkey]

Is heater hose capable or running fuel without being damaged? I don't know. That's the only reason, I'm not real worried about the pressure. I'm just worried that it's going to get all gooey and sprout a small leak some day. Probably not any time soon though.

Does MS have a logic loop for the idle circuit published? I might be able to take a look at that and help with the brain storming. Tuning experimental engines on experimental software was my job for about 4 years.

[TheSteve]

It might be worth looking into, but personally I think itll be fine. It doesnt swell or expand under pressure, and with that short of a gap I don't think it even has room to. If it was swelling a little bit a 3rd hose clamp could be used just bridge the gap and prevent the hose from bursting. I cant imagine the hose being rated to less than 40psi or so, and this is only hitting about 43.5. I do agree though, safety first. I just dont see this as too much of a weak link in the system.

On an unrelated note, the ignition input mod to the MS seems to have helped the poor startup problem. It now starts up after a second or two of cranking. Maybe the RPM signal was spiking to over the set crank rpm and cutting fuel. Who knows. I did notice that in heavy stop and go traffic something is getting annoyed and keeps stalling when I come to a stop. If I keep on the gas its fine, but itll die after a few seconds of idling. I think the IAT sensor might be getting heatsoaked in its location. My normal running temp idle is currently set at about 1300 to try and prevent this from happening once I hit traffic, but it happily idles much much lower when it isnt "overheating" or whatever its actually doing. Its been doing this since day one, too. Logs dont show much of interest when this happens either. Almost "done"...almost

[ATOMonkey]

Standard NPT tap sizes are .250 NPT and .190 (or #10) NPT.

You could also drill and tap the ID out to whatever size is next up on the chart, like a 3/8 or 5/16 NPT. Maybe something to do in the down time. I'm just a little leary of heater hose as an HP fuel line, for safety sake.

[FastJetta97]

dang man..... that looks like a ton of work but its SWEET..... cant wait to hear the final conclusions on it all when its totally done and see what its like...

[TheSteve]

Also, the oil pressure dummy light sensor should be a good place to tap into for a temp sensor. All you'd need is some kind of T fitting and put the dummy light sensor on one end and the temp sensor on the other.

Good idea, dumb idea??

Holy ****, thats perfect! I'm even running one of those on my other car, I can't believe I forgot about it.

As for a fitting on the fuel rail, I'm not quite sure. The ID is very small. Probably about a quarter inch or less.The OD is a more reasonable size for an adapter but youd have to grind it perfectly smooth for a metal adapter to seal correctly.

[ATOMonkey]

Steve, I know your fuel rail doesn't leak, but is there a standard NPT tap and union that could use there? I have no idea what the ID on the GSXR fuel rail is.

Also, the oil pressure dummy light sensor should be a good place to tap into for a temp sensor. All you'd need is some kind of T fitting and put the dummy light sensor on one end and the temp sensor on the other.

Good idea, dumb idea??

[TheSteve]

The engine is 99% the same on a post, so I would think fitting the throttle bodies would be about the same. The only forseable difference is the throttle cable. And I think you'd have more room to work with under the seat for placing the MS box.

Theres sort of a way to log with carbs. With the wideband, it comes with software to log directly onto a computer (no MS required). The hard part would be assigning a tach and throttle position to the log as well. Just logging the AFR over time would be easy, but pretty pointless since you dont know whats happening at that exact moment in time. A better idea might be to buy the LC-1 package that comes with an AFR gauge. You could mount the gauge to the handlebars and just try to remember where the rich and lean spots are.

The hard part really isnt getting an AFR log, its in the other two signals. While the post does have a TPS from the factory it might be hard to tie into the logging software that comes with the wideband. Same for the tach.

http://www.innovatemotorsports.com/products/lc1.php

Check that out. It looks like the TPS and RPM should be able to be adapted to the logging software pretty easily. I'd advise shopping around a little bit, you might be able to find a better price.

[mattjm82]

Is there a way to run those logs off of a carb, or is it just for an MS system? Here's another question, any ideah what the difference would be for putting the injectors on a Post Kat as opposed to a Pre? Or should I just leave it alone and find a Gixxer to play with.

[TheSteve]

Forgot to mention, if anyone wants a copy of the entire log file to look at just let me know and I'll post it up. The logging software is available for free.