Hi Jon,
>As far as your tranny troubles go, do you think it has to
>do with the full throttle acceleration, or does it shift
>erratically all of the time?
The troubles happen only at WOT from a standing start and
then randomly. Under part throttle, it shifts both automatically
or manually perfectly with the Transgo kit. Even from a rolling
start and going to WOT, the shifts are clean 99% of the time.
I've tried everything that I can think off short of an unaffordable
rebuild or pcm flash to raise the shift points... TV cable adjustment,
governor pressure solenoid and sensor replacements, band adjustments,
tranny cooler, Amsoil ATF. All have helped to some extent but the
tranny will still decide if and when it wants to shift. Last Sunday,
I went through 8 runs (longest yet) before it raised its ugly head.
I've tried to control the problem by lowering my "manual" shift points
(with the MP PCM); 1-2 @ 5000-5100 and 2-3 @ 5300. The problem
seems to occur most often when the burnout is prolonged. That's
one of the reasons that I went back to the BFGs from the MTs.
I'm bringing the rpms up at the burnout to about 2500, doing a pretty
quick 2 count (sometimes, even a 1 count) and then leaving for
staging. Tranny temp isn't a problem source as the cooler/Amsoil
has kept the temp. to about the 130F to 150F range.
>I ask because I have been thinking that when I get some time to start
>going to the track again, I was going to try something like putting a
>block under the accelerator or using a throttle stop such that it would
>only allow the accelerator to go 1/2 to 3/4 of the way down.
Hmmmm. Getting back into the saddle just when I'm retiring from the
track :-)
A few years ago, I was trying to come up with an electronic version of
a throttle stop by somehow "controlling" the tps output signals to the pcm.
Did not get very far though.
Last year, I went back to the archives (around 98) when Vlad. etc.were
having the same problem with their R/Ts after putting in the Transgo kit.
They could not figure out the cause. Someone did disconnect the TV
cable (wouldn't want to do this for a long period) and said it worked.
Naturally, there is no kickdown but when you're up-shifting manually,
it doesn't matter. You may recall that I tried it and I got the shifts when
I wanted them but you may also recall that it stayed at WOT (thank god
for the extra 1/4 mile shutdown) :-) BTW, I do disconnect the cable whenever
I do a dyno run so that it doesn't kickdown from 3rd and throw all the
readouts out of whack.
>On the other hand, its probably a good idea to just run your own race and
>get better at picking dial-ins, I suppose. :-) My drag racing strategy used
>to be to pick as best a dial-in as I could, but because my truck wasn't very
>consistent, I would "modulate" on the top end. It usually worked, but
>will lose every time against an opponent who breaks out or a real drag racer
>with an accurate dial-in.
That's basically what I'm trying to do during the time trials. Do the
shifts at
lowest rpms that'll keep me in the powerband and with the greatest probability
that the shifts will occur. 5000 rpm shifts seem to be about it. This will
give me 14.8s/14.9s with an average launch. The 2-3 5000 shift will start
3rd at 4000 rpms, just a little low in my band. It takes a long time (2-3/10s)
to reach 4500 and then it takes off. Doing the 2-3 at 5300 keeps me in the
band and my ETs will be 14.5s/14.6s.
>There is something of an ego factor here, where people will assume you have
>a slow truck, but if it brings in the points and the trophies, I would be
>perfectly
>fine with that. They'd find out different if they tried to start
>something when
>the throttle stop is disabled. ;-)
You are so, so right! It takes all the discipline that I've got not exceed
those
shift points when I know that 5600 rpm shift points will have me in the 14.1s
at least :-( I'll save those for t&t days and only when the weather and track
conditions are great :-)
Last Sunday in elimination run 2, I drew an Explorer (17.92). I had lost
to him in the
first bracket race of the year and he had 3 points going in. I put up a
14.56 dial
and took the right lane even though I wasn't sure I could do my dial in
that lane ...
left was doable. He crossed about 1/2 truck length ahead of me (as well as
having
a better rt) BUT (I said that I was very, very lucky) the light at the
1/4-mile on his
side fogged up and he didn't register a time so a rerun was in store :-) Back
at the staging area, we discussed what happened. He was convinced that he
did not break out and I ran a 14.70. The staging lane manager asked me what
I had in store for the rerun. I didn't say anything and just smiled so I
don't know
if this threw the Explorer racer off or not. Anyway, I had concluded that
there was
no way that I get close to my dial with those shift rpms. I decided to do
a very
quick burnout (1 count), raised my shifts to 5300, hoped the tranny was in
a good
mood and was prepared at the stripe as I was certain that I would break out
with
those shift points. He got even a better jump on me and crossed with about
the same 1/2 length. As I approached the stripe, I got off the gas, gave
the brakes
one hard stomp and crossed with a 14.58. He broke out with a 17.84. I wonder
if he'll speak with me the next time out :-)
>Has Jim been helpin' you out? As much as he races, I'm surprised
>he isn't running points too!
No. I tried to talk him into running points but I don't think that he's
even been
on the track this year :-( I guess that Jim is taking retirement literally :-)
Thanks for the suggestions. Appreciated.
Bob
This archive was generated by hypermail 2b29 : Fri Feb 06 2004 - 11:46:21 EST