SDS CDI vs Pmag

[tspear]

Ross,

What would be slick since the coil is powered off the controller, is have a plug into the controller for the backup battery.
Let the controller handle all power switching, drawing extra power to charge the battery when needed.

Also, I would be in the 70-80 minute camp.

Tim

[rv6ejguy]

Originally Posted by tspear

Ross,

What would be slick since the coil is powered off the controller, is have a plug into the controller for the backup battery.
Let the controller handle all power switching, drawing extra power to charge the battery when needed.

Also, I would be in the 70-80 minute camp.

Tim

No, the coils are not powered from the controller only triggered from it, they have separate power, switching and fusing. This backup battery will power both devices.

Switching power sources will be automatic via the controller.

[tspear]

Originally Posted by rv6ejguy

No, the coils are not powered from the controller only triggered from it, they have separate power, switching and fusing. This backup battery will power both devices.

Switching power sources will be automatic via the controller.

Ok, that is what I though originally but I must have misread a recent post.

Cheers and good luck

Tim

[Chkaharyer99]

Have you established a price schedule for the new SDS CPI and it's options?

[rv6ejguy]

We're aiming to keep the CPI pricing without the backup option the same as now- $1170US. This will be the price regardless of coil mounts chosen. We want to be priced below P Mag which is the big dog in this market at the present time.

There will probably be some other new features added which I can't disclose at this time.

Can't say what the backup option will cost yet but I believe we should be able to keep it below $100. This would include the battery, CNC'd tray, hardware, wiring etc. The control circuitry will be in all CPI boxes so the option can always be added later too.

[Bill Boyd]

It just occurred to me that the wasted spark concept that's so easy to grasp with a 4 cylinder 4-stroke engine is a bit of a head-scratcher with 6 cylinders firing at 120-degree intervals. Seems like the wasted spark(s) would occur about 120* before exhaust stroke TDC and again at 120* into the intake stroke (less whatever advance is being run at the moment).

What keeps the charge from lighting off during the intake stroke? Google search was no help to me

I know you guys have long ago figured this out, but I'm just curious how the need for a distributor is avoided in this application.

[DanH]

Originally Posted by Bill Boyd

It just occurred to me that the wasted spark concept that's so easy to grasp with a 4 cylinder 4-stroke engine is a bit of a head-scratcher with 6 cylinders firing at 120-degree intervals.

It's still a flat motor with opposing cylinders firing 360 apart.

Firing order is 1-4-5-2-3-6, so 2 fires 360 after 1, 3 fires 360 after 4, and 6 fires 360 after 5.

[Bill Boyd]

but I assume there's 120 degrees difference among the firing times of 1 & 4 & 2 & 5, etc.

Still trying to wrap my mind around how that's done in a 6-cylinder 720-degree firing cycle engine without a distributor or without firing a wasted spark during the intake stroke. Or else the spark on the uncompressed ingoing mixture has no effect??

If I'm having a brain fart, just refer me to a Youtube vid and I'll go away.

[Toobuilder]

The 6 cyl coil is really a 3 pack of dual output coils. The wasted spark only occurs on one plug at a time, not all six. The coil driver is what tells individual coil pairs to fire - its a bit like an electronic distributor.

[Bill Boyd]

Originally Posted by Toobuilder

The 6 cyl coil is really a 3 pack of dual output coils. The wasted spark only occurs on one plug at a time, not all six. The coil driver is what tells individual coil pairs to fire - its a bit like an electronic distributor.

Thank you! I can unbend my mind and leave my padded room, now