| misfire will chime in here and support what I am saying. In the Z's I have worked with first hand, 0.044" was too large for 14-15psi applications and the engines will misfire at this higher boost and RPM when there is less dwell time available. That small 10-thousandths of a difference in gap will make all the difference in the world. FWIW: in my personal Z, I had to gap them down to 0.025" to keep it from missing at 26+psi of boost. There is no detriment to power by reducing the gap, in fact, if it is too large, it will misfire at higher boost/revs and severely impact performance. I agree with Damon that a larger spark has more area to it, but very very marginally so. On the dyno we have noted no negative performance difference when gapping down the plugs. The spark itself is so small, independent of gap, that there is not going to be any considerable diference in the flame front at all. There is vastly more area in the combustion chamber that the flame front has to progress across that a few thousandths difference in the size of the spark is inconsequential. When you dropped your gap down to 0.035 from the OEM spec, there was no difference in performance as you apparently weren't experiencing misfire. Try putting some racefuel in your car and turning the boost up to around 18psi with a stock gap and you will, without a doubt, experience misfire. The only detriment to gapping down too small is that it tends to create a random, slight misfire condition at idle and low loads. HKS made the ignition amplifier to boost the spark potential so that you avoid misfire at higher boost levels. Spark blowout (leading to misfire) isn't a myth, it is a reality that every tuner at some point in time will have to deal with. You can either buy this expensive piece of hardware or gap the plugs down. In the Peacemaker, we used the HKS amp and had to run 0.025" in it to keep it from misfiring at some 35psi of boost in those 800+ HP runs. It simply would misfire until we did this. The recommendation to go to 0.035" when turning up the boost from stock levels is to prevent misfire from occuring. I have heard in some cases that people didn't do this and didn't have misfire either. Now, whether or not they would even know what misfire would sound/feel like is another question in itself, but in my experience, the stock gap is too large to run 14-15psi of boost on a stage3TT.
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04:43:33 07/16/06
