OPERATION TIPS
For Muscle Cars and Street Rod Trucks and Street/Strip use.
3speed Automatics and Gear Vendors Standard AutoDrive Electronics
The single most useful tip in ratio splitting through 6 forward gears is to
use the AutoLaunch feature.
When you are standing still with 1st gear selected and the Gear Vendors
dash-switch in the manual mode hit our button so that the red light is showing - that is
AutoLaunch. As you speed up the electronics will initiate our solenoid on the overdrive at
about 20mph and then relative to your rear ratio and tire size the Gear Vendors hydraulic
pump will produce the 1st-over shift automatically at the same driveshaft speed every time.
This is very consistent on the track and automatically compensates for different ring and
pinion or tire size. Using the AutoLaunch feature means you are 28.6% farther down the
road or track before you need to shift to 2nd and so it really lets you concentrate on the
car control and launch. Feedback we get says it effectively stretches time in the cockpit
and you won't seem so busy.
You will find that 1st-over is the only gear with a significant hydraulic
delay from the overdrive (it takes 2.5 times longer to shift than when in high gear because
your trannys output shaft is going 2.5 times slower and that is what drives the pump that
shifts the overdrive). Having said that, this delay is very useful as long as you know it
is there in that gear. Without that delay we would have to measure driveshaft speed or
create the electronics for specific speed on ever car relative to ratio and tire size - but
with the delay - we can use a combination of mph initiation and then the driveshaft speed
automatically buffers the shift point so a 4.88 diff will shift much earlier than a 3.55
diff, like it should -self correcting.
If you are boulevard cruising or already rolling in 1st and you want
to nail the throttle and grab 1st-over , just hit the button as soon as you stomp the gas
and the overdrive will shift at a very appropriate time based on driveshaft speed. Again,
the delay here is handy because a shift under full throttle to 1st-over produces tire
spinning torque and the low speed delay gives us time to get our shifting hand back on the
wheel to control the car. (If you have a floor-mount shift button - obviously you are going
to use your foot instead of your hand to shift).
Note: If you set up for AutoLaunch and roll and then stop again
it will disengage (it sees the speedo rotation and then the stop) so either hit it just
before you hit the gas or at the same time if you may roll before launching.
Note: When you out-shift (turn off) the overdrive it is purely
mechanical and happens about as fast as you can hit the button regardless of gear. The only
exception to this is in the AutoDrive side of the switch where both inshifts and outshifts
are buffered 1sec for the torque converter interrupt circuit which is not doing anything on
your three speed auto as you do not have a torque converter clutch.
So now lets get to 2nd -direct, that would be 2nd with the overdrive
off. You are revving up in 1st -over and want to go just half a gear up so move the main
trans shift lever to 2nd and the moment you start to hear the motor pull down (meaning 2nd
gear applying) hit the Gear Vendors shift button. Most transmissions take about 350
milliseconds or so once the shift initiates so you will find with just a little practice
you can do this real well. You will also become aware that if you have a fully automatic
valve body your main trans may not shift up under heavy throttle right when you move the
shifter but you will hear it when it does. Full manual valve bodies change immediately
but have no automatic functions - with full manuals then it is more the same timing all
the time and listening is not needed, just timing.
So now you are in 2nd-direct and to get to 2nd-over you just hit the
button. After you have revved out in 2nd-over go to 3rd-direct by moving the shift lever
and hitting the button the moment you hear the engine start to pull down as 3rd gear applies.
For 3rd-over simply hit the button.
If you drive the car most times at least once a week you should be a
pro with this ratio-splitting feature in most 12 sec or slower cars. For those of you
with 10 sec and faster cars (1/4mile ET) or those of you who rarely drive your ride - Gear
Vendors makes an AutoShift Sequencer that automates the split. You still command the
overdrive in-shifts but when you move the lever up to the next ratio the sequencer looks
at the command and the tach to pick the appropriate moment to out-shift the overdrive.
As mentioned in the beginning of this tip sheet - The key to
enjoying great gear-splitting is grabbing 1st-over early. 1st-over is such a big torque
multiplier compared to 2nd that you really cannot get it too early. (ie: a 3.55 diff car
with th350 trans - in 1st-over has more torque than a 4.56 car has in 2nd) . You have
never felt this much bark from the car. Many bracket racers feel the car is also more
consistent lane to lane when using 1st-over as it helps hook on the bad lanes. Depending
on your chassis setup, weight transfer, and horsepower this will be true on some cars
and not on others, some cars make smoke the tires in 1st-over (most street tire cars do).
The only time you will use the AutoDrive side of the dash-switch
is when you are cruising and just want the trans and overdrive in Auto. Your trans
will go through its normal 1-2-3 progression and then at 47mph shift in to the overdrive
gear just like it came factory with an OD. When you slow down it will shift out and
when you start up the car it will display the red light meaning it will shift as you
reach the 47mph threshold (so the red light always means the overdrive is going to
in-shift automated - either AutoLaunch or AutoDrive depending on what position the
dash-switch is in - Manual or Auto).
Passing Gear & Shift points.
Your automatic valve bodied transmission will automatically move all its shift points
up by exactly the correct 28.6% speed whenever the overdrive is on. This is because
the governor on the trans is in front of the ovedrive so when you shift in the overdrive
it slows it down. (On the electronic transmissions we send buffered ratio info to the
pcm as part of our kit but its all mechanically done on your three speed - no wonder we
all like-em). What is cool about this is that you will automatically get a useable
passing gear (2nd -over) at a 28% faster road speed than you currently get 2nd without
overdrive. As 2nd-direct is normally too low to do anything but wind out the motor
(no headroom) you should find 2nd -over very nice. When it shifts down to 2nd - over
automatically and you are accelerating and then the trans shifts back to 3rd without
you moving the shift lever (if you want to keep accelerating) hit the Gear Vendors
button when you hear 3rd apply and you will be in 3rd- direct. When you are back to
just cruising, hit the Gear Vendors button for overdrive.
This is also true if you slow down so low as to get 1st-overdrive.
The Gear Vendors AutoDrive circuit will keep the overdrive on until you are down below
25mph - this way the transmission can use the overdriven gears at the appropriate
speeds bring the ratios closer to you and we have no hunting caused by being in the
wrong gear or between gears. Below 25 we know 1st would be the correct gear so then
we turn off the overdrive in both manual and auto positions. In manual it will latch
out and not turn the overdrive back on until you hit the button - In Auto it will come
back on once you get above 47mph again.
Have a blast driving your Gear Vendors equipped ride and give us a
call with any questions or concerns at 800-999-9555. If you are already driving the
product ask for Installed product support, if you have questions prior to ordering your
overdrive kit ask for New Product Sales for muscle cars and racing.
You can send pictures of your ride and comments by email to
info@gearvendors.com
and we will put them up
on our website in our soon to be live customer gallery.
GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020
Toll Free 800-999-9555 • Telephone (619) 562-0060 • Fax (619) 562-1186
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