Stage light / Shift light

Just looking for a few suggestions on the best way to have a stage RPM light that is adjustable and only comes on for a window of a few hundred rpm then goes off when the rpm exceeds the upper setting. Then the shift light works normally for the rest of the run. Can this be done with one shift light? Or do you need two shift lights? Any suggestions or tips would be greatly appreciated.
Thanks Cal

 

Thanks for your responses guys, I have two funny cars one is a TAFC so the MSD switch should work fine with the 44 amp mag. However I also have a nostalgia car with a Mallory mag, any idea how to do that car?
Thanks Cal

 

on our alcohol dragster i just use an LED autometer light, with an msd magneto rpm activated switch, just plug in a 2 step where the chip would usually go in the rpm switch and i just have a switch under the throttle pedal, one 2 step chip is set at 6000 for stage i just bring it up until the light just comes on and im usually within 100 rpm, takes a couple of goes to get used to holding it at that rpm and not having it creep up, then once i mash the throttle it switches to 9800 and it works great

 

Bingo, and it works like a champ. Just make sure you ground it properly.

I ran shielded wiring from the tach adapter to the shift light mounted behind the injector. To make it easy I plug the shift light in to a section of wiring that starts at the tach adapter in the box behind the dry sump tank and ends at the back of the blower below the shift light. I use pin connectors on the wiring purchased at Orvac's electonics in Fullerton similar to those found on the pyrometer junction boxes for the Racepak unit. If we have a fire, kick a head gasket behind number 8, bang the blower or anything else that can take out the wiring out I have spare sections in the trailer making it a 30 second fix. Just plug in the new wiring.

 

Staging/shift light

if you call Electrimotion they can send you a schematic of a way to wire this that is very simple and straightforward. It uses a two step that is switched by a brake pressure switch. I plumbed mine into the front brakes. That way when I am on the brakes while staging the car it is on the staging rpm chip. As soon as I release the brakes it switches to the other chip which is the shift point chip. Dave Germain

 

Hey Dave:

I thought about doing it that way but the RPM never gets low enough to reactive the light off the window switch once you hit the gas and leave the line anyway. I decided less is better when it comes to wiring stuff on the car, didn't particularly like the idea of plumbing stuff into the brake line and it works great...if you properly ground it. Did I say if you properly ground it? Just checking.

Make sure you properly ground it.

RG

RG

 

my tach has a low side i stage with and of corse the high side to shift by one light

oops i forgot to say i activate the low side with a micro switch on my clutch pedal so when i leave it goes to the high side

 

I didnt use a window switch. Just a two step that activated a shift light. But I have a question- on a two step without the window switch does the light go out once I get past the chip a certain amount? Or once activated does the light stay on until it falls below that setting? I know that as soon as I released the brakes it would go off until I hit the shift point chip. I understand Randy's hesitance to plumb into the brake line but I never had any problems with it. It is hard line between the front flex sections so I used a ford type brake light switch to activate one side or the other of the two step. Dave Germain

 

Proper Grounding

Randy,

What was that about proper grounding?

Paul.

 

Paul.

Did I forget to mention to ground it? Yes, it must be properly grounded.

Thanks for reminding me.

 

Hey Dave:

We like to see how hard we can shake the tires (as if to see if we can set some sort of record or something doing it), so I don't like the idea of having extra stuff on my car that can fall off. Especially on the brake lines. I'm sure it's fine, though.

RG