NGK's all the way. My personal experience with Bosh is null and void.

Greg, since you used Champions, I would be interested in hearing how they do for you. My experience has convinced me not to use them. On any 'wet' morning the car cranked and cranked before finally starting, with the resultant puff of black smoke (unburned fuel) out the back when it finally caught. Once running, the engine had rev ranges it was obviously not happy in, and re-gaping the Champs didn't help anything. Substituting NGKs cured all problems immediately.

That was in an L24, with about 9:1cr and standard round-top SUs. Your experience might be different.

Frank

I recently "SIDE-GAPPED" my new set of NGK plugs and saw a huge difference in idle quality, reduced exhaust popping, and reduced exhaust odor. I installed them out of the box to cure a misfire at idle but they didn't fix the issue. After I side-gapped them, the problem all but disappeared, and the car improved in many ways.

It takes some patience and tools to do it, but it is a free mod and DEFINITELY made a big difference.

It's an old hot rodders trick, but still applies today. Especially to cars with antiquated combustion chamber design like ours.

http://performanceunlimited.com/documen ... pping.html

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-Dave
76Z Turbo'd
72 In Progress---DONE!

Thanks with my next plug change I will try that.. What brand did you say you were using? NGKS

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77 280 305 BLUE

What a great idea!
Thanx

I see a couple issues with side gapping.

1. The reduced surface area is going to receive proportional more spark and wear out faster.

Not a problem if you change plugs often.

2. Why this may be ok for you NA guys, side gapping is just going to increase the likely hood of spark blow for those running Boost.

Oh, cool ~ a new automotive phenomenon! Please, vas ist das "spark blow" in dem Turbo carz?

Generic term used to describe the result of ignition misfire from higher combustion pressure, due to higher turbo pressure, which packs more molecules of fuel and air into the combustion area, when compared to natural aspiration or low boost, causing the ionization voltage of the spark plug rise.

The solution to remedy the problem starts with a lower gap than normal, then more spark power from upgrading the cap, rotor, wires coils and/or plug.


Less contact area from the spark plug in the form of "side gapping" will result in a loss of spark at lower boost levels then on an unmodified plug.

I can picture that. Thanks!