Twin wasted spark charge up time

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skelly
Posts: 39
Joined: Thu Nov 10, 2016 8:35 am
ECU Model: S40 Pro

Twin wasted spark charge up time

Post by skelly »

Seasons greetings everyone.

Hoping some of you may be able to help with some dwell figures for me.
I run a S40 on my motorcycle, its fitted with a pair of Dyna 2.2 ohm grey twin output coils and runs wasted spark as many motorcycles do.
The coils are mounted over the engine, under the fuel tank in the usual place and are bolted to the frame in the usual manner.

I'm just curious if anyone can give me an idea on coil on time ?
In the software I can adjust it from 1000 to 4000 microseconds.

Any ideas ?
Cheers.
Skel.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin wasted spark charge up time

Post by stevieturbo »

Test with a current clamp and scope to see where current peaks and levels out. That is your number.
skelly
Posts: 39
Joined: Thu Nov 10, 2016 8:35 am
ECU Model: S40 Pro

Re: Twin wasted spark charge up time

Post by skelly »

I don't have those things sadly.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin wasted spark charge up time

Post by stevieturbo »

Then there isnt really any way to guess.

Other than a lower number will be safer. Too high can potentially burn out the coils.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Twin wasted spark charge up time

Post by Rob Stevens »

You could try reducing the time until you get a misfire and them up it a bit. Or ask Dyna for the technical data.
skelly
Posts: 39
Joined: Thu Nov 10, 2016 8:35 am
ECU Model: S40 Pro

Re: Twin wasted spark charge up time

Post by skelly »

I did ask Dyna.
They were totally useless and wouldn't provide me with any meaningful info at all.
They suggested it was the responsibility of the ECU manufacturer to supply such info.
Bit rubbish really.
Antral
Posts: 194
Joined: Mon Aug 01, 2011 8:20 am

Re: Twin wasted spark charge up time

Post by Antral »

I would try at 2500ms and look at the spark then increase slowly if it looks too weak.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin wasted spark charge up time

Post by stevieturbo »

It's up to the user of any product to determine how they need to use it, especially when using it in a non standard application.
katana
Posts: 455
Joined: Sun Jan 27, 2013 6:08 pm
ECU Model: S60 Pro
Firmware Version: 29

Re: Twin wasted spark charge up time

Post by katana »

stevieturbo wrote:It's up to the user of any product to determine how they need to use it, especially when using it in a non standard application.
How is using an aftermarket coil, designed for a bike and used in wasted spark configuration any more non-standard a configuration? Dyna should know the data for what voltage and time they optimally charge - they've been making them for nearly 50 years! Why would an ECU manufacturer know what coil a client will be using to predict optimal dwell time?

About the most useful reply so far is - 'start low (2500us) and compare sparks'. adding 100us at a time - at least it's subjective!
skelly
Posts: 39
Joined: Thu Nov 10, 2016 8:35 am
ECU Model: S40 Pro

Re: Twin wasted spark charge up time

Post by skelly »

Agreed.
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