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EG8
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Discussion Starter #1


https://www.pegasusautoracing.com/productdetails.asp?RecID=1464

Pretty expensive, but apparently it has a provision for a resistor with a ground incase it would ever be used in a situation where the alt is still spinning and the switch is used.

There is a wiring diagram located at the bottom of the page showing that the switch should be wired with the underhood fuse box main on the same side as the Alt.

As far as I know the main fuse box has no fuse from the battery to the Alt.

So the fuse box really just acts like a small distribution block and doesn't need both wires connected, correct? (So in this case, the battery disconnect switch can be the 'distribution block')



I will draw a small diagram in a few, got to take care of the ol' lady first lol!

I was reading somewhere on DSO about this, and I think even 2j was getting a little lost...
 

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EG8
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Discussion Starter #3 (Edited)
Basically I am thinking to wire it up like so (disregarding the special feature for re-directing the extra alt charge)



Really? Is it more of an unwritten rule? This has a grommet to cover the key when it is connected and disconnected.
 

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Classic Man
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Usually the rules are well written and outlined. I think SCCA is the only body that allows plastic switches. Or perhaps it was the drift crowd that allowed it.

I know 100% for sure that NHRA requires a fully metal and non-removable switch.




this is how i run mine


Ah I get ya.[/quote][/IMG]
 

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Discussion Starter #5 (Edited)
I saw that. But how does that cut the alt off? indirectly by disabling the ecu?

In a way, mine is wired the same way, except the alt is behind the switch also.

So that verifies that I can leave one side of the fuse box 'open' as in my diagram? That is what I am not 100% sure about.

I only remember seeing the location being noted and that it needs to shut off the car (non-NHRA I think SCCA or NASA).

EDIT: quick search gave me this for NASA: http://www.nasaproracing.com/rules/ccr.pdf PDF pg60 (doc pg48 )

15.8 Master Switch
An electrical master switch is recommended on all cars, and required on some, as listed in the class rules. It
should be mounted so that it is easily accessible from the outside. If mounted outside the cockpit, it should be
mounted in an area where it is least likely to be damaged (e.g. cowling near wipers). The switch should shut off
the motor and cut all power except to the on-board fire system and any other life support / medical device. The
switch location must be clearly marked.
 

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Classic Man
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What do you think is going to happen? Why are you concerned about cutting off the alternator?


Just curious.





The engine will not run without spark or fuel from the ECU. The alternator will not spin if the engine isnt running.
 

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94 Integra
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An engine can run with just an alternator & no battery. If the driver is hurt & cant shut the engine off, the master switch wouldn't kill the engine. Imagine if the cockpit is on fire near the key, the hood is crumpled and not accessible, and the fuel pump is still pumping fuel which is leaking onto the still-running engine & exhaust.
 

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EG8
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Discussion Starter #8
Basically, with the diagram supplied from the company it shows the alternator t-ing off of the wire then going to the kill switch. So the kill will cut out the battery but not the alternator on their diagram.

I realize that I understood the one you posted and was all ready to do it, but then I saw the one attached in this post and got confused again.

But I am thinking of literally wiring it up this way:
Battery ---->T--->Alternator
..................... |
......................L ---> Kill switch ----> Fuse box (battery side)

Then Fuse box (Alt side) ----> starter

Phone diagram lol, best I can currently do.
 

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An engine can run with just an alternator & no battery. If the driver is hurt & cant shut the engine off, the master switch wouldn't kill the engine. Imagine if the cockpit is on fire near the key, the hood is crumpled and not accessible, and the fuel pump is still pumping fuel which is leaking onto the still-running engine & exhaust.

danz is correct as well as the op i guess, i cut the main power to the under hood fuse panel

No ECU power=0000 rpm

my alt show 12 v all the time witch is how I like it

just say no to plastic
 

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Classic Man
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An engine can run with just an alternator & no battery. If the driver is hurt & cant shut the engine off, the master switch wouldn't kill the engine. Imagine if the cockpit is on fire near the key, the hood is crumpled and not accessible, and the fuel pump is still pumping fuel which is leaking onto the still-running engine & exhaust.
Yes, it will kill the engine. You are incorrect on that.

The car will not run without the ECU getting power. Its 100% functional.

The alternator has no way to send power to the ECU without it going through the switch. Look again.




I made it though tech more than a few times with this setup, and even had to "prove" it worked (just like everyone else) many times by killing the car while its running for the tech inspectors.
 

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The only way this wont work will be if your running a carb and ignition box or hei dizzy. Other than that its fool proof. Don't over complicate a racecar. Remember the kiss method.

Keep
It
Simple
Stupid
 

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My civic
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Ok, So I actually run one of these.

SUPER simple. Put it on your ground side.
 

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EG8
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Discussion Starter #13
You mean the main ground from trans to body? Because if it's just the battery one, that's like doing the simple Alt test; remove negative cable after the car is started: car dies=bad alternator.
 

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I thought you were just looking for ways to disable the circuit. I was not aware there was a reason you were after the hot wire.

carry on.
 

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alot of tracks require that the master is mounted on the positive wire, or it wont pass tech
100% of the rules I have seen require the master kill on the positive. In late model oval race cars you SHOULD have two kills one master on the + and a button basically a ground short for the ignition on the steering wheel that must be a grounded wire only
 
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