Can I get a sanity check on this plan?
6th gen Honda VFR (vee-four sporty-touring bike with a bizarre VTEC-extreme four valve setup, already fuel injected) which is notorious for odd fuel curve issues. And it can't really handle any mods to the engine like a more free-flowing exhaust or even a better air filter without mods. I want to Microsquirt this bike and since it is coming down for maintenance in the engine bay I figured now was a great time.
The Plan: A new Microsquirt using the coil negative on Cyl 1 as a tach input. This is a parallel install where the factory ECU is driving the ignition and VTEC solenoid, etc. 'squirt uses its own MAP sensor for atmospheric baro adjustment only, I'll be running this in Alpha-N, tapping the factory TPS. Inline coolant temp sensor using a "radiator hose adapter" that basically gives a 1/8th NPT sender location to the installer. LC-1 with a gauge for wide-band duties and I'll temp mount the gauge on the tank using magnets and a single gauge pod. I'll either construct a new FI harness or else reuse the existing one, breaking the harness where it is still a tied together bundle and using some sort of round plastic connector like an Amphenol SJS or similar. This way if I want to go back to stock I simply re-connect the FI daughter harness to the factory ECU wiring and get away from the 'squirt. This also lets me easily add a little jumper harness with resistors for emulating the electrical load of the stock injectors so I can hopefully avoid having an "FI" light on the dash.
I'll create my own wiring diagrams for this based on the factory wiring diagrams that are available plus some others from VFR people on the web. I also know of a guy running a one man shop for motorcycle wiring with a focus on the VFR for things like colored wire, maybe injector connectors if they're special to this bike (which I doubt but never say never), and should be covered there.
Questions: The big one is "what am I missing?", I think that's obvious, and then things like "is Alpha-N the best way forward with the Microsquirt?" or "with this controller should I batch fire all four cylinders together or should I try to do them in pairs or something else?" because this bike has an odd firing order & timing sequence with the first cylinder kind of hanging out on it's own and then a pretty close grouping of the other three, or does this even matter?
I realize that this is not a motorcycle forum but I don't think the Sprockets section would get me good visibility by the right people here and I'm not really on any MS forums yet so I'm hesitant there as well. And there's enough MS knowledgeable folks here that have dealt with ITB's and non-common engines that this seems like a good place to ask.
You may want to page MadScientistMatt. Either that or contact MS- DIYAutotune directly. They are super nice / helpful folks!
www.diyautotune.com
678-261-8789
*** Just be glad your VFR is fuel injected. My 85 has the dreaded hidden carbs, and are a massive PITA to service.
This looks pretty straightforward. A lot of bikes tend to like alpha-N as your typical "mild" motorcycle engine is wilder than many automotive all out racing engines. You may need to experiment with different injector staging methods to see what this one runs best on.
In reply to MadScientistMatt:
I'm told by a guy that has really fought with the engine management on these that Honda went with a blended setup, Speed Density at lower RPM then shifting to Alpha-N at higher engine speeds. Is this something you would recommend emulating or just stick to straight Alpha-N for everything?
What about the batch vs bank vs some other method of firing injectors? This is an 780cc motorcycle engine that delivers about 95hp and 58lb/ft to the rear wheel, stock, so not that extreme.
Oh, and airflow goes crazy around 7,000 RPM with the second half of intake & exhaust valves starting to function per the VTEC system (this is not a second cam profile like normal VTEC, this is half the valvetrain lying dormant until a set RPM) so tuning may be "exciting".
That might be worth trying, although alpha-N would be simpler to start with.
Might be worth creating a 2 valve map with the VTEC solenoid disabled, a second 4 valve map with the VTEC hotwired, and then have the VTEC solenoid signal also trigger a change in maps in the MS. IIRC it can have multiple maps that change on the fly. That way, the MS and the cams switch at the same time, and the transition may be easier to handle that way.
Creating a 4 valve map could be difficult, I don't think these bikes like to run at all with all valves active below 5k or so. I kind of figure that I'll need to focus on that area of the rev range and use up some available resolution there and let the high end coast on fewer engine speed columns of the mapping matrix.
Not a bad idea though, and something to look into where I get this all assembled.
B430
New Reader
6/15/12 3:13 p.m.
Nm... Typed faster than my brain was working.
Tuning is going to be interesting. I would be fascinated to see how you get the duel maps to work as I am going to probably go down that rout so I can use E85. (much cheaper than regular gas in my area)
Since I have been working on a MS project recently I have found that MS units are very sensitive to grounding and power supply. I would be interested to see if your proposed set up would work with you taping in to the various sensors since the ms would not be supplying the reference I don't know how it would like that. Again Matt is the go to guy on this. You may want to go over to the MS extra board and post up over there as well.
MS extra ms2 and microsquirt
I run alpha-N on Dr.Linda's Sportster. It's a MS 1.0 derived work, which I made because uS was still "any minute now" for the previous 3 years and I couldn't wait any longer.
My 20 valve Rolla has VVT and runs alpha-N on a MS 3.0 board using SnS with a V1 processor. Here's the VE table :
Note I have buckets at 4300 and 4400. The cam kicks over at 4400. The 4300 bucket "traps" everything from 4300 down to the previous bucket, and the 4400 bucket catches everything once the cam has changed.
Dean: Well, the only sensor I plan on tapping is the TPS which I think should be an easier one to share. Not having the MS deal with ignition and just using Coil 1 Neg as a tach input to the MS should make life easier in that department. I don't really know if I want to do a dual map, I just need to throw a little extra resolution in around the VTEC RPM point (which I believe is 6800 on my bike).
Hess: Yes, your map is what I was expecting. although I wish these had more resolution available. Just not a lot of columns to go around on a motor that idles around 1,000 RPM and redlines around 12,000 and I have to deal with VTEC in the middle.
Don't the newer units have a 16 x 16 table?
Make sure the tps on your bike is a 0-5 volt unit not a 12 volt one.
