Ignition testing

I scope secondary voltage all the time with my lab scope... A 1k resistor in the signal wire puts you right in range. You can't calculate actual KV without a current reading as well, but I use an inductive clamp for that. In most cases I not that concerned with the actual numbers though, I'm mostly looking at waveform behavior.

I'll have to get a capture of the DLI in action... I've been curious about how it actually worked. Haven't had a lot of time to play with the scope lately.

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Originally Posted by tom93vr4

I wonder about increased stress on the PTU & coils if running 18 - 20V and higher current all the time. A DD probably doesn't need that a lot of the time. I like the idea of switching it on via ecu or some other control only when needed.

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Quote:

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Originally Posted by Jesters Deadd

I was worried about running that voltage all the time. Hence the bsa.
Btw i recommended increaseing the limit to 90% and the dwell time by 25%

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You guys are obviously more familiar with what is adjustable within the Chrome ECU, but it has a lookup table of battery voltage that is a large factor in the dwell calculation, correct?

Assuming that is correct, then if you are feeding a different voltage to the coils that the ECU doesn't see, that could result in some unstable dwell current. Say the battery voltage your ECU is reading rises a few volts, it will shorten the dwell. But your regulated voltage to the coils isn't changing, so the shorter dwell time at the same coil supply voltage would lower the actual dwell current. If you are going to make a higher voltage regulated power supply, you'd almost want to either zero out that table. Or make that higher voltage supply relate to the battery voltage that the ECU sees, so that you could then adjust the table to match.

Yes, there is a table called Coil Dwell Time Vs voltage.

http://www.chrisbehnken.com/Images/p...32815795802640

FYI, that is 15% more dwell than stock.