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does locking a TC based on MPH hurt performance?

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Old 06-18-2004, 02:57 PM
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Default does locking a TC based on MPH hurt performance?

mine locks up no lower than 39mph. the gas is killing me! if i had it lock up at say 31mph would it hurt my performance?


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Old 06-18-2004, 03:47 PM
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Your lockup is controlled by tables that use TPS%
and MPH. So for mileage you would set the low-TPS
values lower (in MPH) to lock, while for performance
you'd probably adjust the mid- and high-TPS% for a
higher lock / unlock MPH. You can have both.

Getting the TCC and gear changes to line up in a way
that drives nice, can take a lot of massaging once you
start messing around.

Lugging the motor doesn't necessarily improve MPG
either. But it might. So might adjusting the low-TPS
part-throttle upshift points lower in MPH. Just have
to see what you can stand, and what it buys you.
Old 06-18-2004, 04:11 PM
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Originally Posted by jimmyblue
Your lockup is controlled by tables that use TPS%
and MPH. So for mileage you would set the low-TPS
values lower (in MPH) to lock, while for performance
you'd probably adjust the mid- and high-TPS% for a
higher lock / unlock MPH. You can have both.

Getting the TCC and gear changes to line up in a way
that drives nice, can take a lot of massaging once you
start messing around.

Lugging the motor doesn't necessarily improve MPG
either. But it might. So might adjusting the low-TPS
part-throttle upshift points lower in MPH. Just have
to see what you can stand, and what it buys you.

geeze. didnt know that much went into it. if i took it to a shop to have it tuned would they have a good idea of what exactly needs to be done or should i come with the settings i want already in mind?
Old 06-19-2004, 10:21 AM
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I think this is one place where your dyno-based
tuner would have a hard time getting things right.
It wants you to exercise the whole envelope and
this is not the forte' of the inertial drum dyno.
It's really more cut-and-try especially since your
interests and what you can stand are pretty
loosely defined. Better off picking up HPTuners
(or maybe you know somebody with it) so you
can mess this kind of thing around at leisure.
I probably went through a dozen tunes getting
my trans settings to where I like them (and this
is far afield from what you're asking for, economy
oriented, mine ain't).
Old 06-21-2004, 01:58 AM
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As far as WOT performance goes, it won't be effected by part throttle lockup changes. BTW, your converter doesn't lock at WOT (at least not with stock programming.)
Old 06-21-2004, 08:57 AM
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What exactly do you guys think could be done to maximize the amount of mpg for mostly city and street with (my setup below). The cam does make it a more tricky tune, mpg wise. Think i can lockup 2nd in city driving and set TCC lockup on shift (does that even work?). Or would that be more abusive than running unlocked?

Throw me a bone here on how to maximize non-race mpg on city/freeway, 99% city (40mph max!, stoplight driving) and maybe some freeway action.

Obviously i don't want any driveline lash or anything as well.

got any examples of say what you might do (yeah i have hptuners, and understand the need to permutate several revisions and try them).
Old 06-21-2004, 10:42 AM
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You're not going to like locking the converter in 2nd with a higher stalling converter. It'll unlock just before shifting which will annoy the hell out of you. And no, TCC lockup on the shifts doesn't work. The option is there but it does nothing so far as I can tell.

Save the lockup for 3rd and 4th with a converter. 2nd gear lockup does work well if you're running a really tight converter.
Old 06-23-2004, 12:05 PM
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I have a ST3500 that will throw a code if I leave it in OD and float the throttle. It's hard to explain and it only happens around town. It was a known problem of the ST's a while back. Anyway.....I learned to drive around town in D instead of OD. It keeps the code from going off and it also locks up the TC at 25mph instead of 35+.

Try it and see if it works. I live in a small town and am always doing 35mph or less. I can get my TC to lock-up at 25 and stayed locked all the way down to 20mph.




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