So I just rewired my dragster and am going to try shifting using the timer on my pro cube. Is there any way to set up another switch for reverse so my shifter doesn’t go off after I back up?

Bypass the delay box with a momentary switch to send 12v to the T brake solenoid from any 12v power source.

So I’d essentially just be running 2 wires to my t brake, one from the delay box, and one from my auxiliary backup switch?

quote:

Originally posted by Jamey2632:
So I’d essentially just be running 2 wires to my t brake, one from the delay box, and one from my auxiliary backup switch?

Yes or you can tee the switch into the wire going to the t brake solenoid, either way. Your just bypassing the delay box to send 12v to the solenoid. I mounted a momentary push button on my dash to back up on or off track.

Why do you want to shift on time, .90 racing or?

If just bracket racing, unless the track is junk, shifting on rpm is more consistent IMO.

Ah tying in after would make a lot more sense than running a wire all the way back. Thanks a ton top38!

Just wanted to try it out. A lot of guys at my local track seem to do a lot better with it. If not I’ve got the wires handy to run from the relay back to the msd. Either way a latching switch for reverse is definitely going to make it easier to back up

quote:

Originally posted by Jamey2632:
Just wanted to try it out. A lot of guys at my local track seem to do a lot better with it. If not I’ve got the wires handy to run from the relay back to the msd. Either way a latching switch for reverse is definitely going to make it easier to back up

I would caution you on the latching switch idea, I have seen many leave these on and get out of the car to find a dead battery or burnt up solenoid. At least have the 12v source switched to the ignition so you can't forget.

If you have a car that'll produce the same driveshaft graph like clock work, shifting on time is shifting at the spot on track, but then again so is shifting on rpm same car.

Not sure how one way could be more consistent than the other, unless ya got a car the driveshaft graph doesn't repeat like clockwork, or an erratic timer.

I always shift on time. My car is as consistent as any on the planet, when the mixture is perfected.

Good point top38, it’ll definitely come from the switched side of the ignition. And the only time I could see forgetting is after backing up in the trailer and the power always gets cutoff then. I’m also trying the led push buttons on all my stuff and the light will only be illuminated if it’s on so I’ll make it a point to add that to the checklist

And I agree mike. I’m in a ridiculously slow dragster that doesn’t hardly ever spin, and I feel like I can trust a timer more than a tach signal but who knows. Gotta try it to find out. Time and distance are guaranteed though. Just my train of thought

Run your back-up switch to the trans brake terminal on the delay box. should not back feed to the box, and I have mine tied to the fuel pump circuit so its off when the motor is off.

In the bracket car I always shifted on time plus I like the ability to make a last minute change if I want. On the Top Dragster I shift on RPM that way if it spins the tires it will shift early and hopefully recover

Depending on your timer setting (and resultant RPM) shifting on time can make your car more (or less) consistant.

Time and distance is not guaranteed in the real world...

quote:

Originally posted by HR3377:
Run your back-up switch to the trans brake terminal on the delay box. should not back feed to the box, and I have mine tied to the fuel pump circuit so its off when the motor is off.

Yes, just land the output of your backup switch/button to the delay box rather than hacking into the transbrake wire someplace.

Thanks Tony and hr! Wired it up last night and worked perfectly