Hi, I'm Ryan Woody and today we've got another Holley EFI how to and I'm going to talk about
how to control a racing transmission with Holley EFI, this is going to be for your higher
end cars like an X275 or a pro mod type of deal that has a lockup converter and a three
speed transmission.
Lock up converter on a pro mod, what I actually do is I use one of the nitrous stages to control
the output for the converter clutch and what I do is set it up as you would a normal nitrous
stage so you need two outputs or two inputs, one being the master enable which I actually
have looped to an output here so I actually use the number 4 JB326 on this to turn on
the in to out output, I just have it looped in the connector back to the input for the
N2O enable.
Then from there, I have a trans brake input set up for input one that will disable the
stage, my minimum, and maximum RPM, then what I do to control the lockup clutch is I have
an activation delay of 2.2 seconds so it'll start to activate the converter at 2.2 seconds
into the run for a duration of 6 seconds so, god forbid, he's way out there and still in
it, it will unlock when he lets off the throttle.
Pedaling control, I have a programmable restart setup on the stage, that way if he's in the
run and he has to pedal for whatever reason, get out of it, get back into it, the stage
restart time is 8 seconds, so what will end up happening if he pedals it, it will jump
past the table that I have down here and disable the stage.
So what happens is, he pedals it, it goes to 8 seconds on the graph here and it won't
lock the converter anymore and that's just how he wanted it set up so that's how we did
it.
And then from there I just go down to the progressive control and I have it set up to
immediately go 100% and then at 6 seconds, it shuts off as well just as another safety
precaution.
And so you could, in theory, adjust this to be PWM, I haven't tried it yet but you could
try to ramp in your converter a little softer if you needed if you had real hard-hitting
lockup.
In theory, you could do a dry stage on this probably and add some fuel if needed.
Another thing you could do is since we have this nitrous stage added, I went ahead and
made a stage 8 that just activates with the release with the trans brake and acts as a
timer so then I use that just so that I can go over to my outputs and I can set up my
trans dump.
So I've got an external dump on the transmission and it's set up, turn on when the trans brake
is enabled so input number one is going to be my trans brake, so when you are on the
brake, it activates the dump and then when you let go of the brake, with this statement,
we also use timer number 8 and it starts counting up.
So you let go of the brake and it stays enabled for 1.2 seconds on this run so a lot of times
people ask, how do I make something active on the brake and then turn it off at some
point after I release the trans brake and this is how you do that, you set up a timer,
N20 timer, there were 8 in this case.
You can use the boost timing as well if you have the boost ICF, which would be right there,
either one will work depending on what your car setup is, for a nitrous car or boosted.
Then the other thing that comes out of this is you can do two different shifts, shift
RPMs, using a timer as well if you have a three-speed or a four-speed transmission.
And the way that you do that is, so we have shifter 12, and shifter 23.
And what you will do is use ground outputs and you'll just take the two wires and splice
them together for the shifter and that will work fine.
And what you do is you take shifter and you take the RPM above, and then you take timer
is above 1.2 and deactivates at 1.4 so the way that this is set up is actually a little
different than what I was describing, the way that this was set up when we attempted
this was we wanted to shift at 75.50 or if it hadn't shifted by 1.2 seconds we wanted
it to shift at 1.2 regardless of our RPM and then the deactivation at 1.4 was just to make
sure that the stage turns off and that allows the next shift to happen.
The other thing that you can do is get rid of this, change this to all.
So now what it will do is it will shift when RPM is above 75.50 and the time is before
1.2 seconds after trans brake release.
So this makes your first shift happen within 1.2 seconds, if you are not at 75.50 yet,
it's not going to use this input anymore, you are going to go over here to your shifter
23, set up an identical, in theory, you will have a different RPM for your 23 shift, but
you'll still use N2O timing number 8, but instead of below 1.2 seconds you'll set it
to above 1.2 seconds.
So you'll know at some point in the run where it's going to shift, where each shift is,
you just need to pick your timer value based on that, if your first shift normally happens
around eight-tenths of a second and your 23 shift normally happens around 3 seconds, set
it somewhere in the middle, 1.5, something like that, whatever works and you are comfortable
with so that if it does miss it or you have an off run, you are not totally overrunning
and hitting your shift point way wrong and it also just depends on how your 12 and 23
shift points are, so this is to help get it spooled up, and what I do is, if your trans
brake is not enabled, your TPS is above some value, so just when you are backing up it
doesn't activate, and whenever the boost is below the value and this is the one that you
change a lot, if you are on a really good track you may want to make this a little higher,
if you are on a good track and you are trying to launch with no boost you'll probably lower
this so it's right below the trans, right below your two step RPM or boost and the only
other thing that I'm doing on this is that I powered the boost control solenoids with
the ECU and that's racing transmission controls really for pro mod and drag radial type racing.