Comments on the State of the Union MicroSquirt info

[sidy]

Just an observation but the VB921 Ignition Coil Driver appears to be a
key success factor for motorcycles, I know space is tight but
provision for 3 drivers with 2 installed would suit 4 and 6 cylinder
bikes the world over. (Im talking z1300 and CBX of course for 6
cylinder bikes).

If 3 is pushing it then 2 is a must, unless someone has a better
technical solution (router board on a M/cycle ?????)


Sid Young
Brisbane

Posted by email.

[BrentP]

I would agree that at a minimum a second coil output is needed. Even if the VB921 were eliminated and you just gave us output triggers. Two output triggers would solve the problem for the 90% case, it would only cause problems for triples.

Motorcycles do not have distributors. The one output would be fine for my single-cylinder roadracer, but there is really no way to make it work for even a twin, especially a V-twin.

For an inline four, I imagine you could fire all four coils every 180deg to make a single coil output work. But I think you would need an external amplifier, I doubt the VB921 would handle that.

I really think the best way is to just have four ignition trigger outputs, no internal transistors at all. The user could either add HEI modules externally, or build the VB921 stuff externally.

[sidy]

I like the idea of 4 outputs as long as the HEI modules are easy to
get and wire in, the Bosch modules look quite good and should both
mount OK and work on a bike. Just need to make sure people understand
that they need to obtain extra parts to make it all happen.



Sid


Posted by email.

[racingmini_mtl]

I think it's a little bit counter-productive to not put a few additional components to have the smallest possible board just to end up having to deal with external modules on the installations that are the most restricted in terms of space (motorcycles). I think that at least 2 on-board VB921 with possibly 2 additional outputs would cover most situations the best. Twins and 4-cylinder wasted-spark would be covered by the board alone and 6-cylinder wasted spark and 4-cylinder COPs would be covered with the addition of one and 2 external modules respectively. I guess that the LED outputs could serve as the additional ignition outputs.

Jean

[Deaninkc]

Great news guys! I'm trying to figure out how you can have full time job, a family life and still have time for all this development I assume the MicroSquirt has all automotive rated components to it can be installed underhood. My other questions concern the predictive code for timing with a multi-tooth wheel. I've been playing with a standalone ignition module similar to the router board. In my calculations I can't see much of an advantage to trying to predict the period of the next tooth pulse and decided that it was not worth adding the complication to the code. What am I missing here? In my calculations using a 36 tooth wheel I could not see it adding to the timing accuracy by more than 1 degree and since the only way to really find out the right timing and injector pulse width is with a dyno, tuning should compensate for any inaccuracies. You guys are the experts, where is the flaw in my logic?

[BrentP]

I think it's a little bit counter-productive to not put a few additional components to have the smallest possible board just to end up having to deal with external modules on the installations that are the most restricted in terms of space (motorcycles). I think that at least 2 on-board VB921 with possibly 2 additional outputs would cover most situations the best. Twins and 4-cylinder wasted-spark would be covered by the board alone and 6-cylinder wasted spark and 4-cylinder COPs would be covered with the addition of one and 2 external modules respectively. I guess that the LED outputs could serve as the additional ignition outputs.

Jean

Personally I think externals are OK, just like the pressure sensor being external. It is easy to locate (and/or heatsink) multiple small modules compared to a single module that is a bit bigger.

The unit is already about 1/2 the size of a common ignition controller, and about 1/3-1/4 the size of a full motorcycle ECU.

Unless there are case considerations, it may be best to just make it a bit bigger and add four VB921 ignition outputs. This would eliminate the "external modules" arguement.

[jcorsaro]

I would be very interested in the MicroSquirt form my future motorcycle/scooter fuel injection projects. Having two ignition coil driver outputs, and future MegaSquirt II code that supports wasted spark is must. Most motorcycles are inline-fours or Odd-fire V-twins and need at least two coil drivers. For car/truck projects the v3.0 board is ideal, with the extra room to modify and repair. I would hate to burn up a microsquirt, smd repair is pain.

[Bryce Ludwig]

I'm glad this has come out when it has. By the time it's been tried out a bit, I'll have my scooter upgraded to a bigger engine and will be ready to MS it.

The one output would be fine for my single-cylinder roadracer

I'm taking this statement to mean that this new board will work very nicely with single cylinder bikes?

[bluetrepidation]

Two spark outputs is something the MS2 v3 board and the microsquirt could all benefit from. But this is a great start. I hope this is something the developers are considering doing in the near future also. But there are ways of getting around the problem for now so I can't see it being a top priority. Everyone keep up the good work!

[Kevin Wood]

I'd like to add my vote for 2 coil drivers. My car is a Lotus 7 style sports car and microsquirt would be great in that application for 2 reasons:

Size: Things are not as tight as a motorcycle but the full size MS does take up quite a bit of under-dash space.

Ruggedness: It's not easy to make a full size MS waterproof without changing connectors and potentially putting it in a bigger case. Even under the dash in an exposed open car (in UK weather) is not really a safe environment for a "standard" MS.

With this development the ECU would take up less under-dash space or, due to its' ruggedness, could be mounted in the available space under the bonnet.

I would say the majority of applications in this type of car are 4 pot with wasted spark, currently running EDIS. With 2 ignition drivers, microsquirt will cover all fuel and ignition requirements for this type of application AND do away with the requirement for an external EDIS module.

There's always the EDIS option for the minority who run 6 or 8 pot engines and want to do wasted spark.

In terms of other requirements, I'd say a couple of spare outputs for a cooling fan and a shift light would be good. I guess the IAC stepper outputs could be reconfigured as gp outputs since an IAC is rarely a requirement, with the added benefit that they can drive a bit more current.

I'll be watching progress with great interest.

Kevin