Folks:
I wasn't able to find too much out there on ignitions systems in
terms of hard data regarding HP gains. There are lots of CLAIMS, but not
much DATA out there. I did find three articles comparing spark plug
wires, coils and stuff like that. Even these articles are not terribly
rigorous. The claims at the various manufacturer's and dealer's web
sites are simply outrageous, and in general are carefully hedged
("...you *MAY* see gains up to 1 trillion HP!" etc). I suppose if your
stock ignition system was on it's last legs, you could in fact see
significant gains. But for a well maintained stock system? Sorry, color
me skeptical.
The first article is decent, although they don't say much about the
reproducibility of the results. Basically every ignition system
delivered the same results. No system was much different from any other
(these was a small +/-1% reading difference, well within the tolerance
of a chassis dyno and the variability of the motor itself). Some of the
aftermarket stuff was slightly better, some slightly worse than stock,
although the Holley ignition system did *drop* the HP by what appeared
to be a significant amount, around 3%.
The second article got a whopping 0.8HP gain with a hot coil, once
again well within the error margin of your typical dyno. This comes out
at around a 1% gain, although they rounded the gain up to 1 HP and 1.3%.
I don't believe that you can get any two runs on a dyno to match within
1%, just due to variations in engine temperature and other sources of
error.
The spark plug wire article (the last one) takes the "best of 3"
dyno pulls. If you know very much about this sort of thing you know this
can be very misleading depending on how repeatable the readings are. If
three readings are 62, 65, and 69 HP, which one do you believe? In this
case, they believed the best one and threw away the rest. An average
would make much more sense, or perhaps taking the median. They don't say
how much spread there was in the three readings they took on each setup,
so I am uncertain how much credence to give to their observed
"improvements".
So, read these articles and decide for yourself.
Cheers,
Vance
http://www.4wheeloffroad.com/techarticles/53778/index1.html
http://www.4x4wire.com/jeep/reviews/jacobs97/
http://www.tprmag.com/issue/4/4_wires.shtml
<http://www.4wheeloffroad.com/techarticles/53778/index1.html>
________________________________
Cogito Ergo Zoom
(I think, therefore I go fast)
http://home.comcast.net/~v.navarrette/
<http://home.comcast.net/~v.navarrette/>
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