JM Performance

Does anyone know how the MSD units read RPMS and how the pills work? Are the pills like resisters? And if so, does anyone know what resistances are used for each RPM?

Thanks,
Matt

riot

Im confused with what you are asking for. I own a MSD Window Switch, and I spliced into the service tach wire in my engine bay by the firewall...seems to work fine.

-ryan

DirtyLude

Ignition passes through it, so all it does is count the number of ignition events within a time window to figure out what RPM the car is currently running at.

The pills are just resistors. If you want to try and figure it out yourself, get a multimeter and test the resistance on a couple pills. You should be able to wire up a potentiometer to have the RPM cut off infinitely adjustable.

JM Performance

Thats what I was looking for....thanks.

93LSivic

So if this is this case. It cuts ignition and not fuel, right? Would you suggest using this as a rev-limiting device since I have a chipped OBD1 Ecu with no rev limit. Which could ultimately lead to a blown motor if I miss shift or I boost too fast in first gear.
Question is, do I use this as rev limiting or no?

Oh, and also, I dont think I really need a spark box ignition like the MSD6AL, couldn't I just use the MSD RPM Activated switch, or the RPM module selector, or **** no thinking about it a 2 stage Module (one for launch ala Hondata and 2nd stage for rev limiter? )

I should just start my own thread about this..........

[Modified by 93LSivic, 10:04 PM 11/7/2001]


[Modified by 93LSivic, 10:10 PM 11/7/2001]

93LSivic

Come on, I know somebody has something to say!! Give me some input!!!!!!!!

QuickHonda

You can also buy a pill that has a little teeny weeny tiny small adjustment screw in it that makes it adjustable. Comes in handy if you plan on playing with the limits alot.