Anyone use something like this between your battery and main battery cable?
I'm sure 150 amps is not enough for a starter motor..... or is it?

http://www.amazon.com/Bussmann-Hi-Amp-Circ...s/dp/B0024JOKM4

I also thought these were interesting too.
http://compare.ebay.com/like/370336644693?...4=263602_309572

http://cgi.ebay.com/200-AMP-12V-CIRCUIT-BR...5QQcmdZViewItem

That's why I put a starter solenoid (think ford style, but it came from Jegs and is slightly different) in the rear to fire my starter and then ran a second battery cable up front with a circuit breaker on it to protect the wire that feeds the rest of the car. You don't have a fuse on the starter, but the "hot" lead is only 12-14" long when the car isn't cranking. Everything else is protected (remote master solenoids to seperate off the alternator to avoid problems with the ignition back feeding when the master is killed and a second one for the master (you could skip those if you like, but I stand by using a starter solenoid in the rear).

Jegs has their own version that's less money, but basically this is the same unit I used:

http://www.jegs.com/i/Painless+Performance.../30203/10002/-1

My breakers came from here:

http://www.delcity.net/store/Circuit-Breakers/

The remote master solenoids I used are from Painless:

http://www.jegs.com/i/Painless+Performance.../50105/10002/-1

On my C4 I used a 250 amp fuse on the cable to my rear mounted battery. I didn't relocate any of the factory wiring, just moved the battery to the back and put a fuse to protect the long wire run from the battery. I never had any issues with a 250 amp fuse, even with 12.5:1 compression, hot or cold weather, etc.

http://order.waytekwire.com/productdetail2...SE%20250%20AMP/
http://order.waytekwire.com/productdetail2...0FUSE%20HOLDER/

I used that fuse with that fuse holder with good results.

Do not use that style. They are the biggest POS I have seen. I have replaced almost all of them on our fleet. They trip too easy. We only use them on our liftgate and the charge cord for the liftgate and almost all of them have failed. The other problem I have seen is the terminals like to break and often work loose. I vote for a different style or brand.

+1

Thanks guys.
Also, you can download a PDF here.
http://www.nxtbook.com/fx/save/dbindex.php...caf71789b0b8b93

FWIW, most OE starters on SBCs run 70-90 Amp Draw. 130 Max or they fail. Specs are 60-130 Amps.

That is some info I needed right there. Thanks.

The dyno sheet where MSD tested my MSD mini starter shows that it stalled the starter at (as I remember), 28 NM of torque and 610 amps of current draw. Just adding a data point. I suspect it will draw 100+ (and maybe 250+ in operation), but that is just a guess.

There is no such this as a quick blow fuse in the 250 amp range, so even if the starter very briefly draws more, the fuse won't blow.

Every engine is a little different, I think I would check my starter draw with a amp meter to see what it is drawing and then make my choice on what size protection I need.

I'm trying to figure out what were wanting to protect? $150 battery or a $90 starter?

It doesn't make sense to put $50 worth of protection in place for those cheap components that seem to be a non-issue in a CMC car.

I would want to do it so if the cable from the battery shorts to ground,1 the cab will not fill up with smoke from the melting cable (assuming the battery is in the pass. compartment), and 2 the battery will not blow up which is not fun and I would hate to be in the same compartment if that happened. So I would say we are protecting both car and driver for $50.

This post has been edited by rocky: Jan 13 2011, 01:48 PM

OK ... I can see that.

So the cable shorting to ground would for two primary reasons....

poor craftsmanship
a crash

One I probably deserve the other I don't care any more.

Mitch good points and I know you know better safe than sorry. This could also bring up the "How far should we go" discussion again

Agreed. Most of the 250 amp fuses will handle 200% for 5 seconds (500 amps). Only if you were to wind up "cranking the crap out of it" due to a no start condition could I ever see you hitting the "duty cycle" and blowing that fuse. I just made the hot lead super short to the solenoid and skipped the fuse. The wire simply isn't hot when it's not cranking. I won't get so much as a spark if that wire grounds out (nice if there was a fuel leak in that crash that had to happen to short the wire in the first place).

How far do we go indeed....

Another thing ... and I'm sure I will be corrected if wrong ... every crimp or joint adds resistance and a potential point of failure.

By installing this "feature" the "risk of failure" increases.

Again, I just ain't seeing the need. If you want "bling" and "wow", then OK. But be honest about it.

I agree with Mitch here - protected routing and passthrus are the first line against a short. I use heater hose where the battery cable can get cut, and the absolute minimum number of connections in the high current path.

I should have clarified this is a bench testing system and specs. Obviously different engines will force a variant in there. I am unsure of specs on a stock 350 or anything else.

This post has been edited by 85t5mcss: Jan 14 2011, 12:51 AM