Discussion on the Hard Rev Limiter module, currently under beta testing. <a href="">Project Information</a>

Moderators: JeffC, rdoherty, stieg, brentp

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Hi Brent
I recently bought a megajolt and it's working well.
and another thing about you rev limiter,
it works limiting the positive current of the coil right, but it cause some preignition, and my cuestion is what hapend if you limit de negative pulse of de EDIS instied of limit the positive current?
i guess you can do that with a similar device, in my opinion it should work better because you prevent the negative pulse and the coil will not fire but it will keep charged ready for the next spark. what do you think?

fernando felix

pd. sorry for my english im try

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Post by brentp »

Hello Fernando,

The hard rev limiter is designed to 'starve' the coil of power, rather than cut power abruptly. When the rev limiter is 'activated' an 18 ohm resistor (the resistor array) is switched into the power supply of the coil. This approach prevents mis-firings ("pre-ignition' as you call it) if the rev limiter is activated while the coil is charging.

Also see the "theory of operation' section of our wiki: ... _Operation

I hope this helps,
Brent Picasso
CEO and Founder, Autosport Labs
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Post by sunray »

I would also add that you can't really effectively starve the negative side of the coil like you can on the positive side. The negative side is really a digital (on/off) signal, I sometimes call it the "make-and-break" signal.

Brent designed it solidly and it works just fine.

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