Questions on Viper PCM signals??

[HP]

I picked up a Jacobs NOS controller(NMM) - It is sold as V-8 specific - and is advertised to be used as an integrated ignition unit with timing control.
I just wanted it for its ability to control the NOS as a RPM function(it pulses the solenoids to meter NOS and fuel, and has adjustable A/F dial).
I just want the unit as a stand alone function - with NOS/fuel control out -
and RPM in.
My question is - it only is set up for 8 cylinder use - it will take input
from either a distributor or it has a crank signal input.
What signal can I tap into to get a simulated 'crank signal' -
it don't have to be exact - just relevant in a ratio of 1/2 or 2 times actual RPM(dials read 0-10,000) so I could double or 1/2 the reading to compensate.
I can't get anyone from Jacobs to respond to my info requests.
Does the PCM Tach signal look like a crank signal?
Would the cam signal work?(if it would I could 1/2 the RPM dial reading)
Or could the coil signal be used as a crank signal input (if it would I could
double the RPM dial reading).

 

[kverges]

That is a tough one, without knowing what voltage, impedance and signal shape the Jacobs part needs, it is a total WAG about what signal to pluck from the engine or even if any will work. There are potential Hall effect pickups, optical triggers and coil/magnet, just to name three of which I am aware.

I guess I would start with the crank position sensor (I think there is one on the '96 RT/10) and see what happens.

 

[HP]

Crank sensor signal on the Viper is a no-go. It is the one signal that
is useless for any performance use(it sends 2 sets of 5 pulses).
I'll keep trying to reach Jacobs - maybe someone in Midland, TX - could
go knock on their door.

The cam sensor signal is a pulsed 180 on, 180 off, 5v / .3v - (1/2 actual RPM)
I'm not sure about the tach signal.
If I have to, I can always install an aftermarket crank trigger for the
input on the nitrous controller. It would still be worth it - since
the Jacobs unit is only $225 and would take the place of a NOS programmer and
RPM window switch - and offer variable RPM control of the NOS and fuel adder,
and let you individually fine tune each for correct A/F.

 

[davem]

Hugh,
You could use the cam sensor or one of the coil drivers. The tach is a voltage, so you can't use that.

good luck,
Dave.