Nolan every bhp helps on the current stock engine. 5-10 bhp on a Neon is
probably 2.5-5 bhp on a Spitfire if you assume similar percentage improvement.
Since this is a brand new oil filled coil it hopefully will take the extra
heat. It supposed to be designed for it. Also I have everything else replaced
on the ignition side but for the old Allison and that goes shortly, so it's all
ready for the higher voltages etc.
Interesting comment on the plugs though. The PO had the Bosch platinum and I
was having problems with them I put in the OE (Champion RN12YC from memory) and
she runs better. My local mechanic who tuned the car for DEQ here, said that
the Champion ones were better for the car.
It's all a start on minor upgrades to improve the overall performance. Exhaust
is next in a couple of months all going well (still not got all the info on
which is best Monza vs Rimmer vs other dual pipe plus corresponding headers
4-2-1 - research ongoing), then carbureter (twin SU if I can get them in UK or
Weber DGV here if not, most likely) but need to keep her relatively clean for
emissions here so probably cannot go for a mild cam as yet.
Alan
Original Message:
-----------------
From: Nolan Penney npenney@mde.state.md.us
Date: Fri, 30 Jun 2000 15:26:42 -0400
Subject: Re: Coil voltage vs plug gap
Grassroots Motorsports did a dyno study on this some years ago. I think the
power gains they were able to achieve by increasing the plug gap was on the
order of 5-10 horsepower. To small to be detected by the average butt dyno
(seat of the pants), but it would lower track times.
This does not come free though. It heats up the coil, leading to breakdown.
It also increases the chances of burning through the plug wires and such. Take
it too far, and you start failing to spark across the plug gap consistently,
losing power and getting a roughened idle.
As a sidebar on the subject, platinum plugs take less voltage to arc over due
to the electro-chemistry of platinum and their center electrode shape. This is
good and bad. On the bad side, this means they are more prone to arc over
before the coil is fully saturated, resulting in a weak spark. On the good
side, it makes them dandy for enlarging the spark by increasing the gap.
As a second sidebar, GRMS also did a dyno study playing with various sparkplugs
when they did a tune-up on a slightly tired Neon. Best performing plug? The
old NGK's that were in there.
>>> "alemen@pop.ftconnect.com" <alemen@pop.ftconnect.com> 06/30 2:05 PM >>>
Folks I have a new coil ready to fit (40kv) and I have seen some references to
opening the plug gap to take advantage of the higher voltage, so that it does
not jump at the old voltage. I higher voltage can jump a bigger gap, that makes
sense, but is there a trade of to the energy at the smaller gap?
Does anyone have the info or perhaps a link to an article on this?
TIA
Alan
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