[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]

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]

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]

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]

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

[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]

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.

[ATOMonkey]

Can you mount the IAT in the air box?

Congrats on getting this thing up and going!!

[TheSteve]

That would be the ideal place for it, but with the smaller gsxr throttles the kat airbox won't fit and the spacing changed from gsxr stock so that won't work either. Gotta go with pod filters unless you can find an airbox that fits gsxr throttles with katana spacing that fits in the kat frame.

[ATOMonkey]

Ah silly me. I just assumed that since you changed the spacing on the throttles that the stock box would fit. I didn't think about the size difference.

I think that the boots on the GSXR airbox are just glued to the box, same with the Kat. You might be able to switch the GSXR boots to the kat box.

I'm just talking out of my *** though, since I don't know how big the hole is that they have to fill.

Either that, or you just cut out a big rectangle in the kat box, fab up a piece of plexi-glass, and glue the GSXR boots in there.

Either way, it would be a pain in the ***.

[TheSteve]

Tried for a good while today to get the engine to idle, but it won't do it. The engine starts and tries to die if i move the throttle, has a very unstable idle. AFRs look ok, between 13-15. Then every once in awhile itll try to shoot up to about 7000rpm and sit there until i turn it off. I'm not sure what the issue is, because everything is scaled right from the 8 cyl settings. I think its just tuning problems, or may even be its overheating thing. Not sure. It does start much easier now though so thats a relief.

My attention to it is a little divided at this point, though. Once I got it rideable I started looking at my car project, a 240sx. Was going to turbo the stock engine, but then came across a screaming deal on an engine from a Nissan Skyline. So I've been kinda busy working on that as well. The bike is still the top priority since its the closest vehicle to completion though. Sucks not having a reliable vehicle since the only running car I had died. Was definitely not planning on having to rush the bike..

[ATOMonkey]

If it's hitting 7k RPM, then enough air is getting in the engine to make that happen. I don't think it's a tuning issue. You could have the throttles open too much to get it to idle in 8 cyl mode.

Any possibility for vacuum leaks?

Also, what does your ignition timing look like? Any compensation for ECT in there too?

[TheSteve]

I think its tuning because I had to crank the idle screw in quite a bit to hold a 1500rpm idle. Every once in awhile itd shoot up really high though. With the idle where it was it'll run for just a few seconds and die. I don't think there are any vac leaks, everything is on pretty securely. Ignition is still handled by the stock ignition box. I didn't even want to try tuning that this time around.

I did the math to see how much fuel would actually be needed to run the engine at WOT and the numbers came pretty close to what trial and error yesterday came to. Guess I'll just have to keep messing with it. The good news is I found some ideal cranking pulsewidths for cold and hot so once I get a temp sensor in there it should start every time easily.

[ericej2344]

I have been following this project very closely. I was planing on doing the exact same thing, so you going first really helps. My hat's off to you, but I have to agree with ATOmonkey. If your bike is revving up to 7k, it has to be taking in enough air to do so. I would start investigating there. Great job man.

[TheSteve]

I got it to idle well enough to ride around the block a few times. I still dont know what causes it to freak out though. Its running fine, then suddenly it takes off (with me on it once). Had to reach down and crank down the idle while riding. My only thought is the sync is off again. Now this I really don't get, the sync seems to need adjustment quite often. Maybe I'm bumping something and screwing it up. I have a feeling that when I hook up the carbtune its gonna show one or two cyls being waaay off. I agree completely though, it MUST be an air leak or something to do with throttle input. The AFRs are good throughout the high revving, so its not the tune.

Starts up easily now though, so I'm making progress.