MSD 6AL2 black battery wire

[2Luke2]

So we have relocated our battery to the trunk. We have a 6AL2 MSD box. The box has a red and black that are supposed to go to the battery. We aren't wanting to run to more wires to the trunk so we wanted to know if anyone knew if the black wire could just be grounded like every other black wire or if there was some magical reason it needs to be connected directly to the battery?

We are also going to have the red wire for the msd box and the solenoid wire all connect at the starter post where we are running the main battery wire. Does anyone see an issue with that?

Thanks!

[firefighter3931]

Luke, are you planning to run a ground wire from the battery to the engine block ? I recommend that you do this because it will make a big difference in how well the engine cranks over. 

I tried running the battery negative to the chassis and the engine would barely turn over.  Then i went ahead and ran the negative wire all the way up to the engine and used that as a ground. HUGE difference....like night vs day ! 

I ran a heavy duty ground strap from the same spot on the engine to the firewall and connected the heavy black MSD ground wire to the firewall using the same bolt that attached the ground strap. Works like a charm.

For the MSD heavy red power wire i connected to the stud on the starter relay.



Ron

[2Luke2]

Hey Ron!

We were planning on running grounds from the block to the frame and from the frame to the battery in the back of the car, but if you are telling us that's going to suck then we will definitely have to put some thought towards running a negative from the battery to the front of the car. Only issue is that we are running 2/0 gauge wire and man that stuff is thick!

Do you think we can get away with a smaller wire over the 12-14' run to the front of the car?

Lastly, by the 'starter relay' do mean the posts on the actual starter or did you put in a remote starter relay?

[firefighter3931]

Hey Luke, you can run the ground to the front frame rail but i would suggest running the battery negative to the same bolt on the front frame rail if you wnt to do it that way. Or better yet, just run it right up to the engine like i did. 

With rubber insulators in the motor mounts you will never get a good ground without a ground strap to the frame or better yet a cable tied directly to the negative post. Trust me...i tried. 

The stock battery wiring has the negative cable attached directly to the cylinder head. Using subframes and spot welded sheetmetal as a ground is nowhere near as good as a direct coupling to the engine. Race cars can get away with it because they mostly use solid mounts or engine plates and the front & back subframes are tied together with frame connectors and roll cages.

Fwiw i'm using 1.0 cable but the minimum I would recommend is 2.0 on a run that long.

With reference to the positive MSD wire....i meant the post on the firewall mounted starter relay switch. There should be a wire connecting that down to the starter.



Ron

[2Luke2]

That sounds like a plan to us Ron. We have the 2/0 welding cable right now for the positive and we should have enough 2/0 negative as well to make the run. We do have sub frame connectors, but you're right we are running rubber mounts and no torque strap. We are going to run it inside the car with split tube loom around it. The wire's OD is 5/8", so trying to fit two of them in the wire running along the side of the door is going to be a tight fit, but I think we can manage.

As far as the positive MSD wire... Our positive wire on the starter relay on the firewall was connected directly to the battery wire(it was like spliced into it. The only positive wire we had going down to the starter was just the positive battery cable, but we figured it didn't matter where it hooked up into the positive line, but we wanted to ask here to make sure were weren't going to melt/break anything. There is also a negative going from the starter relay to the small post on the starter.

We attached a quick picture of the wires we have on the starter relay. The red one is the one that was spliced with the battery cable closer to the battery not on the starter itself.

The black one was connected to the small post on the starter.

The black one below the above black one is some wire we assume is for the NSS, but someone has it grounded out against the firewall. We have a new NSS harness, but haven't run it yet. (work in progress lol)

[2Luke2]

So Ron, this is our question in a drawing.

We want to know if we can run the red wire from the stater relay directly to the post on the starter or if we should splice it back into the battery wire before the starter like it was before we moved the battery. We can't think of any reason why it would matter, but we aren't electrical engineers lol...

So the first picture is how it was before.

The second picture is how we are going to set it up now unless someone tells us it's a bad idea.

[firefighter3931]

Hey Luke, the 2nd diagram is exactly how mine is wired up....works perfectly.  

I also ran a heavy duty braided style ground strap from the black (ground) wire on the head to the bolt holding the voltage regulator on the firewall. This guarantees a solid ground for the charging system and the rest of the car as well. 

http://www.summitracing.com/int/parts/rfw-gc12/overview/


Ron

[2Luke2]

Thanks Ron! We are going to drill the holes for the cable tomorrow hopefully and then get started on the interior. We pulled the carpet up to find out it was original... so we are replacing it, but before we do we are going to throw down a new layer of sealer/paint just to be on the safe side.

Again thanks for the suggestion we greatly appreciate it! We shall take some videos once we get it all back together....

[2Luke2]

So we were able to get everything working... kind of haha... We have a few issues atm.

Does anyone know why a starter might keep running after the engine is started? We currently have the car the wired the way you see it in the below picture. We are thinking bad starter relay, but we are also having an issue where the starter will just whine and then make a loud grinding or popping sound when we try to start the car. When this happens the engine doesn't turn over at all. We made another thread in the engine section of the forums, but it might all be related.

Also wanted to say though that when the starter engages it's FAST and the engine turns right over. So it's a HUGE improvement from the old mini starter we had.