Battery placement vs cutoff switch location.

[robfrey]

Is it okay to put the battery in the front of a streamliner and the cutoff switch at the rear?
Is it okay if the ecm stays connected to the battery after the cutoff switch is thrown.
Ignition box, fuel pumps, water pumps, boost controller, ecm "on" wire, etc will all run through the cutoff switch.
The FAST fuel injection engineers are set on making sure the ecm is directly wired to the battery.

[Milwaukee Midget]

Are they just trying to maintain memory in the ECM?  A separate 12v system, regulated, with a motorcycle battery, or a battery like what is used in a home security system would solve that.

I would want the shortest possible lead between my battery and my cutoff switch, and the reason is that if the insulation is compromised between the battery terminal and the cutoff switch, the resulting short could dump a lot of amperage directly to ground, create sparks, and get hot enough to melt things.

I witnessed a buddy of mine place a hacksaw with no blade in it onto a battery, where it shorted out between the terminals, and welded itself together to the point that it was no longer useable.

My 2 cents - worth maybe half . . .

[robfrey]

I agree but I have a packaging issue. The cut off switch needs to be in the rear to keep laminar flow good on the nose but the battery does not fit in the rear. Left my rulebook at work and I'm in the middle of designing tonight. I'm talking legality not optimum design.

[Dynoroom]

The answer to your question is yes.

[robfrey]

Thanks Mike!
Please tell Ryan and Kevin I said "Hey".

[Speed Limit 1000]

Our lakester has the battery in the front with the cutoff switch and a cable to the pull off lever on the back of the car

[Dr Goggles]

I witnessed a buddy of mine place a hacksaw with no blade in it onto a battery, where it shorted out between the terminals, and welded itself together to the point that it was no longer useable.

excerpt from a post I wrote years back on the DLRA board, batteries can cause mayhem when they short....

I load up the panel van ( EH 186 celica 5 speed ) for a gig and make a U-turn in front of my house , it was a motor that I'd scrounged with a Yella Terra head , a Holley and extractors so for what it was it went OK. I boot it and it goes about twenty yards falters , and stalls...as I put my foot on the clutch it collapses to the floor and the headlights go out ...the car rolls to a stop and a huge cloud of white smoke or steam pours out of the grill.....

I push it back in front of my house , it's facing the wrong way but I'm in a hurry so I get in the HQ sedan,(overnight the cops give me a ticket for parking too far from the kerb....ta)

When I get around to fixing it there is a trail of destruction, the battery has slipped and shorted against the metal clamp down, the clamp has melted and dripped down against the side of the battery and burned a hole through the case, at the bottom ,mixing sulphuric and red hot metal...but before that handy fusible link let go the current took a short cut down the clutch line rather than the engine earth strap and burned a hole in that too.........however ,when I go to look at the clutch problem there is fluid around the slave, the piston seal is on it's last legs , so I replace it...then I try to bleed up the clutch , it just won't ....the hole in the line is strategically placed so that the fluid leaks into the subframe and drips onto the slave.....I'm in the car I can't hear it squirting out of the hole.......you know those simple problems when you think you're going nuts???  The battery was only new too......

[floydjer]

Are they just trying to maintain memory in the ECM?  A separate 12v system, regulated, with a motorcycle battery, or a battery like what is used in a home security system would solve that.

I would want the shortest possible lead between my battery and my cutoff switch, and the reason is that if the insulation is compromised between the battery terminal and the cutoff switch, the resulting short could dump a lot of amperage directly to ground, create sparks, and get hot enough to melt things.

I witnessed a buddy of mine place a hacksaw with no blade in it onto a battery, where it shorted out between the terminals, and welded itself together to the point that it was no longer useable.

My 2 cents - worth maybe half . . .

O.K....I`ll ask. He did THAT on purpose??? I have an associate who shorted across battery terminals to light a torch....He now has one eye and some ugly scars for a reminder not to do that.