Hi, Papa C
That is one fine looking Durango!
At 01:10 PM 7/20/00 -0400, you wrote:
>The Quick-D is supposed to give me ~30HP also. I'm going to re-gap
>the plugs very soon to 0.035. Any suggestions on how to do this
>without tapping the end on something hard to make the gap smaller?
I have not used either the Quick D nor the K&N Gen II (which advertises
25 hp gains on a Grand Cherokee, I believe) and the most that I have
seen posted in real world conditions is about 0.1 sec. off the ET for
the Gen II.
That's the gapping method that I use. Dr. Jacobs or MSD sells a nifty gapper
which is supposed to be quite the thing but it's too expensive up here
in Ontario if you find one.
>When I ran a 16.08 it was the first time I ever ran at a drag way. I had
>a very poor reaction, the O/D was on, and I didn't get my RPM's up at all
>during launch...I just let off the brake and stomped the gas. In all of
>my 16.1X runs I got the RPM's up only to about 800-1000 RPM...any more and
>I start spinning the rear wheels. It doesn't bog down at all during
launching.
Forget about the reaction times when trying to lower your ETs ... it is
not included in nor affects the ET. Those rpms sound about right when
racing on street tires. A small bit of 'chirp' off the line doesn't hurt
too much ... it's an audio feedback that you've leaving the line with
close to the max. amount of power to the ground for your vehicle.
>I reset the MP PCM when I installed it about 2-3 weeks ago, but did not
>reset it right before racing.
I reset my PCM during the time that I put on the drag radials. With my truck,
I will usually run my best times on the 5th or 6th run. Others will get their
best on the 3rd run with little difference afterwards. A performance shop
owner
resets after every run ... he said that he had enough evidence from his own
studies that seem to indicate that the drive back from the traps to the pit
area is learnt by the computer and affects ETs (?).
>Tire pressure during the 16.08 was around 30. The other were around 18-20.
On street radials, I've read that 5 lbs. under factory recommended pressure
gives them best traction and times. Also, drive around the water pit and
just spin them a few times to clear off tire debris. Rubber compound in
streets radials are different from drag radials and slicks. Experiment
in 1 lb decrements until your ETs begin to increase when using the same
launch techiques. Lowering too much and the tires will drag too much
on the track and cost you time. The ones that you want to raise are the
front tires for less drag. Right now I'm running them at 40 lbs (max.
pressure on sidewall says 35) but have not done too much experimenting. My
son
who was pit crew for a racer said that they found that they could run well
over
the max. pressure on the sidewall with no worries of blowout and that's
sustain
speed and cornering on road courses.
>Trap RPM's I'm not sure about. I never really kept track.
Try to get a reading of trap rpms a few times ... the times and mph on your
site are fairly consistent so that they should be close. This will come in
handy if you decide to dyno your Durango. IMHO, I think it's worth the
investment if you are serious about setting personal bests.
In my first race, the Dak ran 16.8, 16.7 and 16.8. I put in the MP PCM
and promptly ran a 16.1. As mods were done, I found myself stuck at 15.4.
I started noticing that my traps around 4000 rpm which I felt was too low.
I made a mod change which gave me traps at 4500 rpm and lowered my ETs.
At the beginning of this year, I finally found a dyno shop within an hour
driving distance and had my Dak dynoed. Right after the dyno, I installed
the MPI. After a couple of visits to the track, I was running the same
or a bit slower. My inkling was that the MPI had moved the power peak
up the rpm scale and that I had no more track to use the power. I re-dynoed
and it confirmed that power hp was now at 5000 rpm from about 4500 rpm.
Same scenario ... plenty of power but no more track to use it. I made
a mod change and it resulted in going through the traps at 5000 rpm and
a lower ET (0.20 so far). If I had not re-dynoed and my inkling had been
wrong, then I would spent about $950 CDN and wondered what was going on.
>I think my Durango actually weighs a little more. I believe when they give
>weights on vehicles they have to give an average. Since I have added the 3rd
>row seats, leather, running boards, 4 wheel ABS, 5.9L, etc...I think the
weight
>is around the 5,000lb mark. And, with my weight (190 lbs.) and the half to
>3/8ths of a tank of gas it's probably closer to 5300 lbs. The Goodyears
>(275/60/R17)I have on there now are about 30" (29.9" to be exact). My stock
>tires were 31"x10.5"
If that's is correct about the weight, then your low 16s are great numbers.
If I were in your place and my goal was to break into the 15s, I would invest
in a couple of rims (AR-767 are probably the cheapest) and a set of 28" drag
radials and I would be very confident that I would be in 15.s.
>Do you think a shift kit is needed?
I don't know how the 46RE operates but if it is anywhere nears the 44RE
the 2-3 shift is a killer as far as slippage is concerned at WOT. I know
that I have to start the 2-3 shift near 5200 rpm because once the gear
has completed its shift to 3rd, rpm will start at 3300. Anything lower
and I am below my power band and I will waste time before the motor can
get back into the power band. That is why I shift manually ... auto.
shifts cost me 0.2 sec every time.
Sorry for the length. If any DMLers feel this should be taken off-line,
just let me know.
Bob. Ont, Canada.
'97 Dakota CC, 5.2L, 4x2, 3.92 SG, auto., 4265 lb.
PB: 14.737 @ 91.75 9.364 @ 72.95
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