Window switch & delay relay

[1nicenova]

I jst ordered an msd window switch pn#8969 & an arc time delay relay pn#1402 from summit. Hoping these 2 will work with my digital 6 box. Called msd and they said no problem using the w-switch with the digital box. I ordered the delay relay thinking I can use that as my solenoid activation relay that will have a built in delay. Anyone using a setup like this? I was going to go with the new nos mini controller but I dont think I need all those features yet. I want to activate the nitrous after realeasing the transbrake or off the footbrake. I also have the full throttle micro switch mounted. Thanks

[ERV JR]

I think Craig watson used the same setup on his car for awhile, get him to take a look at this, I would be intrested in it since i have the same box and need to find a way to bring the unit in later ,since i cant piggy back the timing control with a digtal box to pull timing on the launch

[John_Heard]

Adam - Do you still have that diagram I drew up for your car? That ought to be pretty close to what 1nicenova needs I think?

[Craig W.]

Yes, I used a ARC delay relay on my Digital-6 box with pretty good results. You can use it two ways.

You can either use it to delay the nitrous activation or use it to delay turning off your step retard. I've done it both ways (depending on the rules of the organization I was racing with).

Delaying nitrous activation is a no-brainer Just wire it up as you would a regular relay. Just beware that if you want no delay, you'll have to wire in a regular relay. When you set the ARC relay to zero, it won't activate.

To delay the timing, set your base timing where you want to be going down the track on the bottle. Then wire up the ARC relay to be normally closed. Trigger that relay with your nitrous activation and it'll pull out the amount of step retard until the delay setting is reach and then it'll open up the connect, taking away the extra retard. Just beware that its a step retard and not a ramping in of the timing. So its much harsher.

The trick to both of these setups is to get the car to full power while you've got maximum weight on the rear tires.

I ran 1.35 in the 60' with these setups on the 8.5" slicks.

[ERV JR]

I was told thta an msd 8981 would allow me to create a timing curve with the knobs on the side of the box and it would work with a digtal 6 box but havent heard much about them or if in fact it will work

[John_Heard]

This may need to be adapted, but maybe it will get you started

http://www.dragstuff.com/techarticles/i ... agram1.jpg

[1nicenova]

Thanks for all the replies. Everything showed up today. But now i'm stuck at work the next 2 days. Have to wire it up after work.
Looks like i'm going to go this saturday provided my vacuum pump shows up tomorrow and give it a few breakin runs & see what it will run. Wont be running it on the gas just yet. The following week is our Nostalgia drags maybe i'll get to run it on the bottle then. I think my tires are shot as well. Left them on the car for a 2 summers & a winter outside. Not sure if I should stick with the drag radials or go to the et streets.
Thanks for the schematic I'm pretty sure that will work.

[stroker1]

Nice diagram. But I don't really see the purpose for the relay thats before the delay switch. All the delay is doing is switching on the main relay for the solenoids. The delay switch or timer doesn't draw that many amps does it??

Just curious! Stroker1

[John_Heard]

It's a transbrake relay, it interupts the nitrous from turning on while the brake is activated

[Craig W.]

The relay before the timer allows you to be at full throttle on the transbrake without spraying nitrous. Once you come off the transbrake, the timer starts and then engages the nitrous after the set amount of time.

You don't want to be sitting on the transbrake/on the 2-step and spraying nitrous.

[79 Camaro]

Stroker 1, I have my car wired just like the diagram that John sent you. It works great, trust me. Just make sure you get the right relays

Very easy wiring and like I said, it works great. Thanks to John

Adam

[stroker1]

The relay before the timer allows you to be at full throttle on the transbrake without spraying nitrous. Once you come off the transbrake, the timer starts and then engages the nitrous after the set amount of time.

You don't want to be sitting on the transbrake/on the 2-step and spraying nitrous.

Thanks for clearing that up. I didn't realize the relay was involved with the transbrake.

Yeah, Craig, I know you cant (shouldn't) spray against the brake, I just figured the brake and 2 step must be set lower than the low side of the window switch.

In the diagram I cant really tell how the relay was triggered. I dont see the 85 terminal being connected to anything. I thought that was the terminal that switched on the relay. I guess my main problem is that I don't really know what all the terminals are on this particular relay. I am familiar with the 87,86,85,30 relays.

So you have to trigger the timmer when you release the brake, that I understand. But how is the relay triggered? What terminal? When you let off the brake button, you lose power to the brake solenoid. But how do you gain power to trigger the relay on the timmer? Or are we gaining ground on the other side?

Help a dummy out!

Stroker1

[stroker1]

Ahh, I might have just figured this out. 87 and 87a are opposite function. One is normally open and the other is normally closed. Is this correct??

[John_Heard]

Yes that is correct. The transbrake relay uses a normally closed set of contacts and the solenoid relay uses normally open. Maybe I should add something about that to the drawing.

Note: Some relays - (Adam had to fight this one for a while) have two sets of output terminals but they are both normally open, so you have to make sure that you're getting a SPDT - Single Pole, Double Throw switch to get both the normally open and normally closed outputs.

[stroker1]

Yes that is correct. The transbrake relay uses a normally closed set of contacts and the solenoid relay uses normally open. Maybe I should add something about that to the drawing.

Note: Some relays - (Adam had to fight this one for a while) have two sets of output terminals but they are both normally open, so you have to make sure that you're getting a SPDT - Single Pole, Double Throw switch to get both the normally open and normally closed outputs.

Thanks alot John!! Hey one final question for me, the 85 terminal on the brake relay connects to the wire feeding the brake solenoid, right??? This is not real clear on the drawing. Or atleast on my screen.

Later-thanks, Chris