924Board.org

B · Joined: 25 Apr 2006 Posts: 487 Location: Ohio

hey everyone

I was going through more electronic fixes and noticed that some of the grounds that are attached to the motor are looking a little ragged (to say the least) - these are the larger braided wires. I wanted to know if I could replace these with a shielded battery cable - ? and should the length of these be kept the same?

any thoughts would be greatly appreciated.

thanks very much
Sean
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Shielded is fine (better?!). Length: as short as possible. More importantly: gauge => as big as you can afford. Our cars are insufficiently grounded to begin with. Putting in fresh ground straps with bigger gauge is a Very Good Thing.
_________________
erstwhile owner of just about every 924 variant ever made

B · Joined: 25 Apr 2006 Posts: 487 Location: Ohio

thanks -

I will take care of that asap

Sean
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

Octane · Posted: Thu Jul 08, 2010 3:41 am Post subject:

Good grounds are crucial. This is 1/0 gauge pure copper welding cable with copper lugs soldered on both ends. I ground the paint off to bare metal where it attaches to the block, then it runs about a foot to bare metal onto the motor mount plate which is welded to the body. There's another smaller 4-gauge ground hidden on the other side as well. If there's one thing I learned about ridiculous car stereos it's the importance of good grounds. Shielded is definitely the way to go. The 1/0 is about the same diameter as a quarter.

A 25' roll of 1/0ga welding cable was about $65, probably overkill for these cars but it's definitely worth it. I needed it to trunk mount my battery anyway, and still had some left over to re-wire my F-350's batteries.
_________________
- Brendan
1977 Porsche 924

Slam · Posted: Thu Jul 08, 2010 3:49 am Post subject:

That's just so... Green! What a color!
_________________
'84 944 - kid blew motor
'83 944 - resting comfortably. For 12 years
'87 944 - sideswiped by trucker
'80 924 - gone
'78 924 - gone
'77 924 - rusting comfortably

datatrain · Posted: Thu Jul 08, 2010 5:23 am Post subject:

Battery cables with flat connectors come in all lengths. Just measure the distance and buy a finished battery cable cheap. They make excellent ground wires as they are heavy gauge. They work for me !
_________________
'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR

Harm · Joined: 02 Apr 2009 Posts: 1376 Location: Holland

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

!tom · Posted: Thu Jul 08, 2010 11:42 am Post subject:

By shielded, do you mean insulated? There's a difference.

The insulation can hold water in once it gets wet, which can speed the process of degradation of the wire. This would be the mechanism that Harm was discussing.

I can't see any benefit to shielded wire at all. I don't know of a compelling reason why an insulated ground wire would be preferred, and if Harm is right, there's reasons not to.

If you could ensure a seal between the insulation and the wire, that would be different.
_________________
78 924 NA
5-lug

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Good point on the taxonomy, tom, should be "insulated" not "shielded". I guess I was just thinking that protecting them from the elements as much as possible would be better than leaving them open. My opinion is based also somewhat on the fact that virtually all modern cars have insulated ground cables. But maybe we're splitting hairs...anything you do to freshen up and increase the size of the grounding straps on the 924 will be a benefit, insulated or not!
_________________
erstwhile owner of just about every 924 variant ever made