I'd like to start a new discussion, err... debate.

When I was younger I used to sneak my Mom's Firebird 400 out when she went to bed (before I had a drivers license ;-). The car had an auto transmission. Not knowing any better then, I discovered that I could make this Bird run faster shifting thru 1-2-3/4 manually. My, could that bird fly!

I tried this (lightly) on my truck a couple times. Oh my Gawd.....

I have a Transgo shift kit installed, as well as a Superchip. I plan on installing an auxillary cooler this weekend. Over the years, I have come to realize the importance of that particular piece of machinery, and I do look after it.

So, knowing topic this will draw many different opinions, what are your thoughts on manually running thru the gears with an auto tranny?

I'd like to here from some tranny builders, as well as from those who may have been doing this since...well, forever. And, of course, anyone else who would care to opine.

Thanks, let er rip!

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What does the guy who dies with the most toys really win?

 

It sounds to me with the mods you have done to your truck, that trying to shift it yourself will only make you go slower.
It was true in the older automatics that you could go faster by shifting yourself.With new computer controled automatics, escpecially with your mods, that the computer can shift much faster than you could shift yourself.It may feel faster, but if you took it to a drag strip and tried both way I bet just letting the transmision shift itself would be faster.
I do not know what shifting yourself will do to the durability of the transmision.

 

Good point Don. I agree with you that the computer probably does shift faster. But, at what RPM and speed? With the Trango shift kit holding at any RPM, you can run the RPM and speed higher before shifting from 1-2, and 2-3. The shifts may not be quite as fast. But, I would think there would be less delay, and quicker response since the speed and RPM's are higher than the computer would allow, before electronically shifting. Therein lies the question of potential damage and/or excessive wear on the tranny.

Hmm... would be interesting to see the difference in the 1/4 mile.

 

Shift speeds are identical because the gearshift doesn't actually shift the tranny.
It is simply a electircal switch just like the ones they used to use to control the nuetral start and backup light funtions on old transmissions.
The electrical swith tells the computer what gear to put the tranny in.

 

at milan dragway
shifted my self 17.8
letting the trans do the work 16.8
seems not to have the same get up and go
when it's put in the lower gears
i think it's in the computer to retard the timing.
yes manual shifting always worked for me in other cars and trucks.
but this truck just likes to do the shifting


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99 XLT SC 4x4 STYLESIDE ORP 5.4,AUTO & 3.73 POSI
MED. TOREADOR RED
EXTANG TONEAU,BED MAT,
K&N FILTER & WOOD DASH KIT

 

Two things-

By shifting manually, you are probably shifting outside the powerband. If you think it is pulling hard in first, try shifting to second.

The manual lever is still connected to the manual valve, but now, the MLP (manual lever position) sensor tells the PCM which range you have selected.

 

Mr. Manx:

Q: Did you launch in 4wd?

Q2: Did you experience 'excessive' wheel hop if not?

Q3: Was/is there any repeatable difference in times for 4x4 vs 4x2 runs?

Jim

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"00" XLT SC 5.4 7700 4x4 SB repeat buyer