Re: Whats up with plug gaps, and some other stuff.

From: Bob Tom (
Date: Tue Aug 10 1999 - 09:01:59 EDT

At 01:12 AM 8/10/99 -0700, you wrote:
> [snip]
>I am not sure who was experiencing the power loss, I had a person notify us
>that he was having some trouble after installing the TB, but after the
>had a chance to reset itself, the problem was gone. It seems that while the
>computer is relearning, it tends to be really inconsistent.
> [snip]

There was a report from an R/T owner who improved e.t. by 0.8 sec in the 1/4
with your 52mm tb but, when in combination with the Leach headers, the
was down to 0.6 sec. ... recalling from memory.

>I have an electric fan, jet pulleys, jet thermostat, jet stage II, 52mm TB,
>billet spacer, My Filter kit, JBA Y pipe, Headers, and a Flowmaster 2
>MSD 8.5s and the Accel coil........
>Stock Gap is 40, I had opened it up to 55 but mileage took a dump. What gap
>should I try next.....I was going to try a colder plug, but its all getting
>confusing. Any ideas?

Determining the optimum gap for your engine requires that you take the effort
to do home-grown testing and careful evaluation.
Begin with MSD's gap recommendation.
Drive in your normal fashion for about a week or so (get track times if
  increased performance is your goal) and record mph.
Open the gap by 0.010" (some recommend 0.005") if increased mileage is the
or close by this amount if performance is your goal.
Perform the same driving ritual for the same period and keep identical
Repeat opening/closing gap and ritual until performance/mileage suffers.
Once you have reached this point, then reset gap to the last setting by
your last closing/opening by the 0.010 (or 0.005 ... whichever you
originally chose)
to get the optimum setting for your engine.
When gapping, make sure the side electrode is flat, 90 degrees (perpendicular)
to the center electrode, and centered directly over it.
It is time-consuming but the only procedure that I have come across.

Hope this helps.

Burlington, Ontario

'97 CC Sport, 5.2L, 3.55, auto., 4x2, flame red

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