IMPATIENT 1

ok, been playin with the msd prodata software and trying to figure out the safest way to add timing when the meth injection is turned on so this is what i've came up with, critique it:

ok, base rpm timing curve of 17* straight across
map timing curve adding 10* in vaccum(total 27*), at 14.7(atmosphere) i start pulling 1* for every lb of boost up to 10lbs where i end up at 17* maxed(without retard,meth turned on)

ok here's the tricky part:
im setting the nitrous timing retard to remove say 3* when the 12volts is applied to the retard wire from the box. im wiring my meth injection setup with a relay of course to turn off and on the pump , and i'll wire the retard wire from the 6012 to the "rest" side of the meth inj relay so as long as meth is turned off, the retard wire is getting 12volts from the relay, when meth injection turns on(at 6lbs boost) the 12volts to the retard wire drops out, which should add the 3* back into the total timing.
am i missing something here or is this the safest way to add timing with the 6012 when the meth injection comes on? basically my setup will be in nitrous retard whenever the meth pump isnt turned on, when it is the retard drops out.

btw, this is in a dragboat, my rpm operating range is 800rpms idle, 4000rpms cruise, 6500 wot

at 5lbs boost and 3*retarded with meth off id have 19*
6lbs and meth turned on id have 21*
7lbs and meth turned on id have 20*
8lbs and meth turned on id have 19*
9lbs and meth turned on id have 18*
10lbs and meth turned on id have 17*

if at any point above 6lbs of boost my meth pump doesnt turn on, it keeps the timing retarded 3* basically, hopefully saving my stock bottom end lol

slow67

iTrader: (2)

Instead of triggering it with the pump feed wire, what about putting a pressure switch on the output side of the injection pump in case the pump fails.

IMPATIENT 1

yeah i thought bout that too, but i'm hope'n the basic principal works out. i can always find a a/c cycling switch(may handle the meth better than hobbs could, im guess'n tho) that closes at say 35psi and put it on the pressure line to the injectors, run it to a relay to control retard of the timing. i want total control of the timing cuz i fully plan on pushing it to 18lbs as soon as i nailed my wot afr at 15lbs with the carb, so i want retard if the pump isnt on.

slow67

iTrader: (2)

Yeah the theory sounds good to me (with a 5 pin relay, use 87a pin to the MSD unless you find a pressure switch thats normally closed and opens at whatever PSI you shoot for).