Electrical "Flyback"

[tq60]

It's a bit late, but...

In our state vehicles, we run a pair of number 2 size welding wire, red and black from battery to where the distribution is located.

A max 50 fuse is common, but a larger breaker on some, this is at a battery source.

From ignition, we have a small wire, usually 12, just for durability. This is fused with 4 amp.

At distribution, there are buss bar style fuse blocks, usually 2 with a large isolated 3/8 grouding stud.

A 40 Amp bosch style relay is located here connected to the hot buss, controlled by the ignition wire, supplying ignition controlled power to the other buss.

In your case, this all can be placed in a hidden but accessible space.

Sent from my SM-G781V using Tapatalk

 

[markba633csi]

Yes you could use the "dirty" power to turn on a relay which would then supply power straight from the battery
If that's what you were asking

 

[pontiac428]

Yes it will mess up your ignition, coil volts drop at 5000x the input voltage, so you want good strong hots and grounds. Remember that EFI injectors are the same way, they only meter accurately at constant voltage.

 

[alloy]

I am running #2 wire to the starter and to a ground on the bell housing. I have a power distribution block on the firewall that came with the AAW harness that has a #4 solid copper wire that supplies power to it from the starter solenoid. It has mega fuses on it. This works great if I wasn't adding the new fuel injection. I also have a ground buss bar I guess you would call it in the battery box. I'm grounding the new fuel pump and the fuel gauge to it, along with my amplifier. All other grounds go directly to either the bell housing bolt of the ground bar.

I'm glad to know I can run the dirty power to turn on the fuel injection. I've become fairly good at doing wiring, but it's not my favorite thing to do. I really didn't want to run more wiring and a relay (ignition on source) for the injection. That would add one more component (relay) that may fail and leave me stranded.

Speaking of wiring, on my nova I had a local shop do the floor pans on it after I had my stroke and the owner has looked at my cars and asked me if I would be interested in doing all his wiring work. I said politely as I could said no. Actually I wanted to say **** no but I did my best not to offend him with my answer. I do cnc work for him now and then.

Thank you everyone for your help on this. I really appreciate it.

 

[alloy]

Yes it will mess up your ignition, coil volts drop at 5000x the input voltage, so you want good strong hots and grounds. Remember that EFI injectors are the same way, they only meter accurately at constant voltage.

Ugh................well after your response I called holley again ( this time only a 35 minute wait on hold---a new record) and asked about running the dirty power to turn on the sniper and he said he recommended a separate dedicated high quality waterproof circuit breaker. Especially if I'm running the holley ignition system which I plan on doing later.

Now the question is do I need to run another wire to the battery to supply power to the relay, or can I use power from the 10awg wire I just ran to power the system? I think I know the answer already but want opinions on this.

I ordered a bosch relay from amazon, supposed to be here tomorrow. I'll believe that when it's in my hand. For now I have a cheap relay I can use to set this up and then change to the bosch relay. I have some good quality 18awg wire I can use to run back to the battery. Should be big enough wire to just turn the system on I hope.


New target date to drive car 2026 it seems.

 

[alloy]

Double post

 

[verbotenwhisky]

I eventually plan on going with the holley stand alone distributor for the sniper. Doesn't require the CD box, just a coil.

Holley Sniper EFI 565-340 HYPERSPARK SMALL CAP CHEVY V8 SB,BB

HyperSpark Ready to Run adds plug and play ignition timing control to any Holley EFI system. This line of distributors comes with a built-in ignition coil driver, removing the need of mounting an ignition box or external coil driver. The design includes a single Hall Effect sensor providing...

www.holley.com

The instructions for the sniper says get the engine running without the holley distributor. I guess they figure one less thing to troubleshoot if there are problems initially. Makes sense. Engine runs very well as is, it's just very cold blooded with the carb.

I'm not sure if the sniper works with a crank trigger setup. Nothing in the instructions about that, just about a CD box.

I am building a 350 for my brothers boat with a Holley system, complete with ignition and EFI... When I revive my Big Block I will likely do the same for it but it will require 2 of the throttle bodies, should be interesting...

 

[alloy]

I am building a 350 for my brothers boat with a Holley system, complete with ignition and EFI... When I revive my Big Block I will likely do the same for it but it will require 2 of the throttle bodies, should be interesting...

I'd bookmark this thread if I were you. Might save you a lot of headaches

I think holley has a setup for 2 throttle bodies.

 

[verbotenwhisky]

I'd bookmark this thread if I were you. Might save you a lot of headaches

I think holley has a setup for 2 throttle bodies.

They do. My big block has a 1100 CFM Holley Carb sitting on it now I was looking at the sniper a few days ago, I'll either go that route or a Hilborn system.

 

[alloy]

I've seen the hilborn looking system that is electronic injection. They look so cool. I'd love to have one but I can just imagine what the price is.