[s-cars] Fwd: ONe more time (via the White Courtesy Phone) Paging Mr. Gailus, Mr Paul Gailus...LS2 coil adventures part 17...

[qshipq at aol.com]

 Thanks for the forward Bill, and I don't see any argument with what was posted.  A couple comments.  If I understand the exercise we are going from 13.7v to 14.5 volt regulator.  To Pauls theory that double v= sqred energy...  Let's define that = with a .7v increase feed voltage on a 5ms dwell time on a LS2 coil, you might get lucky to affect dwell by -.3ms.  Which is why I'm having a hard time buying this whole fix.  More specifically, I think something else is going on, and if a -.3ms dwell 'fixes' lost spark, the edge of failure is awful close.  If indeed there is a feed voltage variance (I'm still having to imagine 15amps at 10sec or less affecting feed voltage by any significant amount), then there is a charging system problem, not really a voltage feed problem.  IOW, a stock rebuilt alt and/or new battery should  have the same affect.  

If indeed Paul is right that the dwell is actually 3ms on the ECU, then the LS2 coil is going to come up way shy of it's 40kv rating, whatever feed voltage is applied.  Again, if this is the case, my understanding and study of ignition systems is, spark plug gap has a greater affect on the amount of spark voltage required before blowout.  

To be clear, I haven't *disagreed* with anything... yet - I'm still getting a grasp on the claim.  I believe I have a pretty good grasp on how ignitions/coils/plug/charge pressure relationships work, now including the LS2 coil.  I've pulled a few of my ignition library references out of curiosity, but the more I read here, the more I'm convinced the LS2 coil is not a good 'upgrade' for the S car.  If the fully charged time is 5ms (- .3 with a 14.5v VR as JC noted), you don't have a lot of spark energy at 3ms dwell.  In which case, I'd be looking at some 50kv MSD monster to have a better margin of spark energy at 3ms.  IIRC too, the LS2 coil caps it's charge, that is to say, even if you give it more than 5ms dwell time, there is no more spark energy, which would quantify Paul's formula for voltagex2=energy^2


Still intrigued, not sold

Carry on

Scott J
coffeex2=energy^2

 

 

-----Original Message-----
From: bill mahoney <airbil at gmail.com>
To: s-car-list at audifans.com
Sent: Fri, Feb 11, 2011 1:07 pm
Subject: [s-cars] Fwd: ONe more time (via the White Courtesy Phone) Paging Mr. Gailus, Mr Paul Gailus...LS2 coil adventures part 17...


(Dunno where some of this disappeared to... but heres the whole response I

hope.)



 We'll thanks, Bill M for the vote of confidence.... and the invitation

to jump in the middle of what looks like a big feud on the list  ;-)



As some have mentioned, you'd have to make real measurements to know for

sure what's going on.



Perhaps the original regulator was defective, and it was oscillating or

causing other electrical noise that was false-triggering the internal driver

circuits of the LS2 coil.