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[GMCnet] MSD Digital GM High Energy Module [message #112328] Tue, 18 January 2011 09:27 Go to next message
bdub is currently offline  bdub   United States
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Registered: February 2004
Location: Central Texas
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Anybody using one of these? Heard anything about them?

http://www.summitracing.com/parts/MSD-83647/



Heard at the Classics rally last week that it makes a good bit of
difference, .. cranking time and increased responsiveness. Nobody had ever
heard of one going bad.



I think I'll give it a go and keep my known good module as a spare. Just
cause I can. J



bdub

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bdub
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Re: [GMCnet] MSD Digital GM High Energy Module [message #112331 is a reply to message #112328] Tue, 18 January 2011 10:23 Go to previous messageGo to next message
Gary Casey is currently offline  Gary Casey   United States
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Registered: September 2009
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I have no reason to believe these won't work just fine, and the speed limiter
might be a good thing (although I think the typical 455 will never be at risk of
overspeeding :-) However, as usually the case, the hype is a little
contradictory. It says it increases the coil current by 50%. However,
increasing the current above that which saturates the iron in the coil does
little good. I suspect the standard module either saturates or comes close to
saturating the iron. And then they say by increasing the current it "saturates
the coil faster." Huh? This is nonsense - the only thing that can reduce the
time to saturation is increasing the voltage, and the coil already sees full
battery voltage. The standard HEI module already has a feedback circuit that
adjusts the dwell to provide a fixed peak coil current at all rpm. Maybe I'm
just another old curmudgeon, but I doubt that the device could produce any
significant improvement in spark energy. I wouldn't spend any of my money on
one.
Gary Casey

Anybody using one of these? Heard anything about them?

http://www.summitracing.com/parts/MSD-83647/

Heard at the Classics rally last week that it makes a good bit of
difference, .. cranking time and increased responsiveness. Nobody had ever
heard of one going bad.


I think I'll give it a go and keep my known good module as a spare. Just
cause I can. J

bdub



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Re: [GMCnet] MSD Digital GM High Energy Module [message #112342 is a reply to message #112328] Tue, 18 January 2011 13:27 Go to previous message
Keith V is currently offline  Keith V   United States
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Registered: March 2008
Location: Mounds View,MN
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Senior Member
bdub wrote on Tue, 18 January 2011 09:27

Anybody using one of these? Heard anything about them?

http://www.summitracing.com/parts/MSD-83647/



Heard at the Classics rally last week that it makes a good bit of
difference, .. cranking time and increased responsiveness. Nobody had ever
heard of one going bad.



I think I'll give it a go and keep my known good module as a spare. Just
cause I can. J



bdub

http://picasaweb.google.com/GMCClassics



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http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist




Oh they fail...
But I have one on my Vette. Now remember it's a high performance high compression engine, I could definitly tell the difference between the stock dist and a new MSD dist and a 6AL. Started faster and easier, less spark scatter.

Would I put one on a motorhome?
Nope. They do make a ignition module replacement for HEI distributors, I could see doing that, no I really couldn't...

A good HEI distributor should be more than enough for anything.
Lots of racers use HEI with a divorced coil


Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
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