dontz125 wrote:Hi, there! Always glad to see another rider in this sea of cages ... What bike are you squirting?
dontz125 wrote:1. Given the small amount of oil under discussion, you may be borrowing trouble. Premix is used because it works. That said, for a street bike it can be a major pain in the butt. The MS3 does include a number of "generic PWM" outputs that could be used to control a high-speed valve. I would suspect that, rather than control an injector directly, you'd be better off controlling a valve (like a water-injection valve) feeding a fixed-orifice nozzle. See this link for the generic PWMs http://www.msextra.com/doc/ms3/genericpwms.html, and this link for a description of a water-injection rig http://www.msextra.com/doc/ms1extra/MS_Extra_Hardware_Manual.htm#waterinj - yes, it's MS1, but it's the best I could find! You may want to consider an actual 2-stroke oil injection pump with throttle cable from something like the RZ/RD series or similar.
dontz125 wrote:2. What sort of servo are you talking about? Most of the older PVs used 'dumb' 5-wire servos, which were basically a 2-wire DC motor (+/- to open, -/+ to close) with a TPS-style pot close-coupled to the servo output shaft. Unfortunately, the code doesn't currently support this sort of beast, but I'm trying to bash together a control board that would take a PWM signal (from another of the generic outputs) and use that signal to drive the PV servo.
dontz125 wrote:3. I'd just go with the EGO sensor. The problem with EGO and 2-strokes is the oil (and sometimes the lead, depending on the fuel) contaminating the sensor, but until it fails you'll get good reliable readings, and you should still be talking hundreds of hours. There have been a number of people, here and over at the RZ/RD500 site, who've added EFI of various brands to various bikes, and most have used WBO2 sensors. Note that the reading doesn't have to be ACCURATE so much as it has to be REPEATABLE.
billr wrote:Did you have a typo, meaning 350W and not 35W?
dontz125 wrote:If you're going road-racing then I really would just stick with premix - I used an AccuMix jug for many years with my TZ125, and it's the matter of a minute to quickly and accurately make a fresh batch. The fuel injectors really won't care - just a SWAG, but I'd almost think they'd give longer life with less chance of corrosion and fouling between races.
dontz125 wrote:Electromagnetic valve - do you mean a solenoid valve with PWM positioning? Yes, absolutely - that's one of the two common 'car' idle valves.
dontz125 wrote:Spark control - the MS can certainly control spark. With the dual plugs, will they be fired together, or separately? If together, you're still talking a single coil driver and control channel for both coils / plugs. If you want one to fire after the other (2 deg? 5 deg?), then you would need a second driver, and you would set it up as an "odd-fire" V-twin (with a REALLY small included angle ... )
dontz125 wrote:Gauges - This is a racebike, not a Wing-abego touring barge! RPM and water temp is all you need to worry about watching while screaming down the back straight; leave the rest for datalogging. There are a few options for that, too.
dontz125 wrote:Power - there are race cars and bikes (some even running EFI! ) that run total-loss off a battery; LiFePO4 batteries are wonderful things. All things being equal, a single injector and single coil running sequential will have 1/4 the power draw of a comparable 4-cyl. The pump is a significant adder, but there's a fellow named Madhu (sorry - can't remember his user name) who has been doing great work on PWM control of the pump vs rail pressure, and has seen HUGE reductions in pump power consumption. By starting the bike while hooked up to a pit battery, the pre-heat of the WBO2 is removed as a drain. Or, as you say, you could graft on an alternator. Modern 3-phase voltage regulator / rectifiers are quite stable and reliable; note that you'd still need a small battery for start-up (to power the MS and prime the system) even if you decided to push-start the bike - it IS a 2-stroke! Also, non-battery alternator-regulator systems can be tricky to design; if you lay it out like a typical bike or car and just omit the battery, you'll fry your regulator and then everything else downstream.
dontz125 wrote:I realise you stated this thread asking about the MS3, but depending on your wish list it really sounds like you could use an MS2 or MicroSquirt.
dontz125 wrote:Last question, and this one's a biggy - What does your crank trigger pattern look like? Bike OEMs like to use long teeth, sometimes 30-60 crank angle degrees in span. The standard MS triggers have significant issues with anything much past 5 degrees; there has been a significant success by one fellow on a specific trigger wheel design, but this still remains as a potential show-stopper. Will you be using a VR or Hall sensor?
Most 2-strokes and off-road 4-strokes are CDI. Most road bikes are TCI. Mixing and matching is a fast way to damage to damage the coils and other components. Both types of coils need some type of 'driver'; some of the newer car TCI COP and CNP designs have built-in drivers and only need a 5v logic signal from the ECU. A TCI coil needs a high-energy transistor, whether an IGBT or a Darlington. The current MS "best practice" is the BIP373 3-stage Darlington available from DIYAutotune; it's practically indestructible, and will shut down if the dwell settings threaten to fry it (and your coil!). CDI obviously needs a charge/discharge circuit; if your alternator is typical low-volt (30-60vac), you'll also need an inverter to generate the 250+ DC volts that the firing capacitor needs.PVO22 wrote:I'm thinking together initially however I have thought about staggering them later on. From what I've gathered with the coils I wont need an ignition driver correct? The coil can hook up directly to the ECU? What type of coil do I need to be shopping for? Most bike coils are CDI type so I would guess that these won't work? I would say an inductive type coil would be what I need but I'm still not really sure?
For a two-stroke race bike, tach and water temp are the traditional gauges. EGT is definitely a tuning datum, which you don't care about in the middle of a race - leave it for the logger. Water temp is important for engine life, especially in a stroker. Run it too hot, and you lose power and then seize. Hammer it too hard before you're up to temperature, and you seize. ("Cold" seizes - gotta love 'em!)True, I'm curious as to why you're taking water temp over say an EGT gauge? Is there a tuning/engine monitoring method based off water temps that I should know about?
Fair enough. One thing to consider is the size of the ECU - the MS3 is BIG, while the MicroSquirt is quite small. One point to ponder (tying back to the ignition concerns) is that the latest version of the uS has deleted the BIP coil drivers, and is 'logic' only. I'm in the process of starting my own business, and one of my products will be a 2-channel coil driver to address this.If I could control fuel, ignition, and at least one PWM output with a MicroSquirt I may consider it which after reading about it I think I could. I initially chose MS3 as it has the most features and tunability. I'm still in the "what's best/what do I need/what's most feasible stage" so I haven't made any concrete decisions yet.
Good plan; just make sure the trigger pattern is something the MS can recognise.I think I'll be going with a VR trigger and adding the trigger wheel to the flywheel.
dontz125 wrote:Also, non-battery alternator-regulator systems can be tricky to design; if you lay it out like a typical bike or car and just omit the battery, you'll fry your regulator and then everything else downstream.
dontz125 wrote:The VR for a battery-less system has to be designed with some sort of limiter to prevent this run-away self-destruction. I THINK that a small resistor (10k, 1/4W) wired in parallel across the +ve and -ve terminals would suffice - but I haven't worked up the courage to try it yet!
billr wrote:You still are going to have the problem of how to start it.
PVO22 wrote:So would a simple solution be to install a VR from a system that already doesn't use a battery? For example use the VR off a snowmobile or ATV that has a batteryless electrical system?
dontz125 wrote:The more I think about it, the more I'm convinced to retract any comments on a batteryless system and just recommend that you go with a battery, whether total-loss, semi-loss, or full-charge.
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