Juice for MSD box

[antmnte]

How do you guys have it hooked up? I have mine on the big terminal on the starter,is this ok or should I put it on the battery terminal.

[shaun callaway]

Re: Juice for MSD box

you should be ok, but which msd box do you have?

[70.5CAMARO]

Re: Juice for MSD box

I am not standing right in front of my car but i thought that i have that switched with the ignition.

[antmnte]

Re: Juice for MSD box

6A

[malc]

Re: Juice for MSD box

Mine is connected to the alternator.

[dieselgeek]

Re: Juice for MSD box

On the MSD 6a it's a tossup between alternator and battery (we're talking about the BIG red wire). I prefer the alternator ans having the other electronics that are sensitive to noise, go directly to the battery lug on their own dedicated wire run.

[squirrel]

Re: Juice for MSD box

Mine is connected to the battery. The battery is under the hood, not in the back of the car, which makes it easier.

[Robert1320]

Re: Juice for MSD box

On the MSD 6a it's a tossup between alternator and battery (we're talking about the BIG red wire). I prefer the alternator ans having the other electronics that are sensitive to noise, go directly to the battery lug on their own dedicated wire run.

MSD and other should always and only be hooked directly to the battery (+) and (-).
Never ground it to the chassis. And keep the box inside the car, not under the hood.

[dieselgeek]

Re: Juice for MSD box

On the MSD 6a it's a tossup between alternator and battery (we're talking about the BIG red wire). I prefer the alternator ans having the other electronics that are sensitive to noise, go directly to the battery lug on their own dedicated wire run.

MSD and other should always and only be hooked directly to the battery (+) and (-).
Never ground it to the chassis. And keep the box inside the car, not under the hood.

Actually, that is what MSD says - but it's not always the best choice for analog electronics. Sorry to argue with you, but it's the definite truth. The MSD can cause noise such that, if you hook it to the same lug on the battery that you hook something like a BigStuff3 or Megasquirt to, you can induce what's called "Power Coupled Noise" into sensitive electronics. The 6a is a strictly Analog system, which means it's less susceptible to noise (and likely to cause noise). Most people think noise comes in through the grounds, but it doesn't - this is well documented in the Bosch Automotive Handbook, which is the guide the OEMs use to lay out their designs for late model vehicles. If you check out any OEM car, you'll see the engine computer is on a dedicated power run, separate from the ignition, electric cooling fans, and any other "noisy" power drain.

Finally, MSD will tell you themselves if using a 6A with something like a BigStuff, it might be better to power the system directly off the alternator lug, because when running, the flow of power is from the alt to the battery - not the other way around. It can cause upstream "power coupled noise" and from my experience, this is the cause behind roughly 20% of EFI cars with "tach noise" problems...


Just my experience as an EMS designer, yours may vary. I worked with MSD's engineers when we did the eMS-pro, and they are some *incredibly* smart guys - they helped us redesign our "points" spark outputs so that our box would interface happily with theirs. Again, there are great minds behind the products at MSD.

Not trying to argue, just laying it out from an electronics nerd's perspective,

-scott

[Robert1320]

Re: Juice for MSD box

What is this BS3 and Megawhatever.
I know blow - thru turbo stuff doesn't work and all.........

(Just joking)

If you can afford BS3 you can afford a Digi 7.
Then you could have issues if attached the alt.
The Alt can spike the Digi box on start up.

Battery chargers and welding can do damage too.

[dieselgeek]

Re: Juice for MSD box

If you have ae BS3 there's no reason to have a Digital 7, unless you run a distributor and need to overpower it because you're arcing two gaps... and if you are that far, why fart around with a distributor?

hehe your turn Smiley

[Robert1320]

Re: Juice for MSD box

What do you think we are doing? Only making 12-13 total hp....

Of course we need all the spark we can get sometimes we have a hard
time jumping any gap bigger than 0.023"(at times). I don't know why
it's not like we are making power or anything. :0

lol

Maybe 2k+hp or more thats all!

[dieselgeek]

Re: Juice for MSD box

HAHA - I've seen your work. I have no comeback :thumbsup:

[antmnte]

Re: Juice for MSD box

So...Should I leave it or put it on the battery.I have it grounded on the firewall.

[malc]

Re: Juice for MSD box

I was advised by M.Hamilton of MadElectrical to connect to the alternator.
I run three wires off my alternator to three of his terminals, one to dash/battery, one to my light/rad fan relays and one to the MSD box.
After the car has started the alternator provides the juice, not the battery.