PSI rev limiter for 2 step

Whats the lowest rpm a psi rev limiter can be set for? Could I stack them and switch one with the clutch pedal set at 6000 for the launch?

 

You could probably stack them, but you'd have to make a custom double drive spud piece, as there isn't any way to stack the factory PSI drive spuds. They are 2/4 pin Mallory or Dunn cross on the mag base end, and a keyway'd shaft (for a Mallory or MSD mag) on the other end. You'd have to make a custom one with a Dunn cross on the bottom, then two pullies (one to run each PSI) in the middle, with a distance separating them, and then the Mallory keyway shaft hole in the top. Sounds like a lot of work!

Chris

 

you need to call PSI myself I don't think it would work.Dave

 

Why not use an MSD 3-Step?

Brandon Booher
NHRA TAD #34

 

The question I was really asking is if anyone knows the shim thickness to rpm and if it will still work at lower rpms like 6500 . I'm sure its a soft enough touch to use as a two step because Ive had it hit at 10000 at the big end and I know you mill off the shim to raise the rpm but I forgot how much. It been since the mid 90's that Ive messed with it, its just been a 10500 limit.

I just was thinking about putting another one on it at 65-7000 wired with the clutch in so I know where the r's are, since most of the time the f an indutive pickup tach doesn't its a piece of sh.t. 0 or 10000 jump to the middle. Anyone feel me?

I dont put a msd three step in my car because I have a mallory and I dont want to but a bunch of electronic gizmo bu.ls..t in my car and an alky motor dont need that much mag . Im trying to keep it under 2400 pounds Aluminum can #25, I lost #20 and I even quit drinking beer most of the time.

 

just having my PSI serviced and you can not just buy RPM ring and use them it don't work that way..you have to send the PSI off to them and have them set up your PSI for what rings you wanna use...do you know how a PSI works if you do you know it wont work as a 2 step..DAVE