--On Monday, June 03, 2002 9:34 PM -0400 Dick Rasmussen
<rasmussend@mindspring.com> wrote:
> It always scares the $h!! out of me to even think about reving an
> unloaded engine to the rev limiter.
Yeah, me too. But is it actually worse for the engine to rev it up unloaded
than it us to rev it up under load?
> What kind of rev limiter? If it is a microdynamics, Pegasus can
> check/reset them. I found trying to do it myself in the car resulted in
> either a low setting or an "oh my God I rev'd to how high?" setting. If
> it is an MSD, try a different module or dial setting. If it is a rotor
> type, all sorts of variables change the limit point from my Lotus
> experience years ago.
It is a Microdynamics. I figure maybe under years of vibration maybe the
potentiometer has slipped, or perhaps years of heat have finally toasted
the thing.
> What kind of tach and does it have a telltale or playback? If so, what
> does it say?
Wish we had one. The fact is, of course, we never look at the tach, so I
don't know why I waste 5" of dash space on it. I should just put in a 2"
tach, if such a thing exists, and use the rest of the space for one of those
fancy shift lights or something. The current tach is a very simple unit
with lots of bounce anyway, but it's never been important enough to replace
it.
> This all assumes: First that what you thought was the limiter wasn't a
> missfire. Second, that you accurately measured the fuel usage. How do you
> measure? If it is a dipstick, with the wind I saw on the Weather
> Underground records, maybe the reading wasn't accurate.
Yeah, it was rather windy. The gusts were enough to make you take a step
back just to keep your balance at times, and the steady wind rushing past
your ears was loud enough to be annoying. But I don't think it affected
the dipstick reading.
Certainly it could have been a misfire, but if so, it sure sounded an awful
lot like a Microdynamics soft-touch rev limiter.
> My best guess for "slow" is a combination of rusty drivers and, if you
> used the tires from last Fall, crusty tires. Once your butts get
> calibrated to crusty tires, it is hard to recalibrate in just a few runs,
> especially if the temps were as cold as the reports I saw indicated. With
> "no" traction, when could you get aggressive?
Yeah, they were last year's Nationals tires. Everyone else was on fresh
rubber, while ours had two days of Nationals, one day of the Al Holbert
Memorial Championship event, and one day of shakedown by Bob last weekend --
twenty runs total. But while it was cold, it was also sunny, and our
tires were sticky enough for your hand to stick to them if you placed your
palm on them. Jim took durometer readings, but I don't know what they were.
The courses were all slaloms and offsets and S-turns, with the exception of
the big turnaround at the end. Courses like that are easy on tires and
grip -- grip really isn't that much of a factor anyway, but the tires seemed
good and it's fairly good concrete. So tires might have been a factor, but
not a big one.
Certainly the drivers were rusty. No doubt about that. I was late on just
about every single slalom and offset gate and S-turn. But I was also on the
rev limiter (or the misfire) quite a bit while faster drivers weren't, and
we used a lot less fuel than normal, so something's gotta be up.
Anyway, thanks for the thoughts. I'll go through the ignition system
looking for misfire possibilities, and I'll call around and see whether
there's someone who can calibrate the rev limiter. I'm guessing it would
probably be cheaper to buy another one than send it to Pegasus for
calibration, but I'll call about that too.
Mark
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