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NHRA compliance with Battery & Fuel Cell rules


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For those that have a battery and/or fuel cell in the rear on their car AND have passed NHRA tech OR are confident their car will pass, what is the aceptable method to seperate the passenger compartment from the battery and fuel cell??

 

As I read my 1995 rule book (new membership for Christmas)a bulkhead must seperate these two areas. I installed a bulkhead in my Chevelle and passed (tech looked at the switch, but didn't check operation), BUT how does this work with the rear hatch? The hatch comes down and meet flush with the divider-is that acceptable?

 

Oh yeah, another NHRA tech question. Anybody have problems with that NO Welded Spider Gears rule? I've got Scottie-GNZ's old 3.36 R-200 "Lincoln Locker" icon_wink.gif and believe he didn't have tech problems with it, but I also don't know how tough the tech guys were at "His" track. Any comments gang? Scottie??

The tech seem to be a little stricter in Division #6 than some of the stories I've read about here ... ie, never let you run into the 10's (or 9's) w/o a cage like the do in some part of Texas.

 

I'd prefer to error on the side of caution, in case, heaven forbid, I actually won a race and a sore loser called me on a tech violation.

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  • 3 weeks later...

Can you get away with boxing the fuel cell and battery? IMHO this might be a beter way of containing something then a bulk head if the hatch is takin into consideration. It works with our local rules here in NZ but, thats for road racing.

 

Cheers

 

Douglas

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My track follows the NHRA rules but do not enforce all the rules like they should. They are strict about not racing in shorts, helmets for quicker than 12.99 and jackets and a cage for quicker than 11.99. They have never questioned me or the legion of racers we all know are running welded rears and a 300ZXT went high-9s with the OEM IRS. He switched because of breakage.

 

Off the top of my head, here is what I recall.

 

A relocated battery must be in a sealed metal or special plastic box. It must have a master cutoff switch with the switch itself outside the car and clearly marked. A fuel can have a max capacity of 16-gals and must have a firewall of (I believe .032 aluminum and .024 steel) to seal the interior from the cell. The top of the cell must not be above the tires.

 

HTH

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Check out th esetup on my site. My cell is where th espare was and has a sheet steel plate over it with a little "house" to cover the door to the filler. It's a PITA to fill through the hatch but it meets regs. My battery is in a sealed box with a vent - it also passes icon_biggrin.gif

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Guest JAMIE T

How would they know you've got welded spider gears? I won't tell, if you won't tell! Ya know what I mean? Scotties diff. ran flawless for years. I wouldn't worry too much about that. As for your battery and cell, just use alum. to make a barrier and let it seal against the hatch. That is acceptable. Most hatch backs are done this way. Or, you can put each into a box with lids. Battery boxes(not marine battery boxes) are common in hatchbacks. Good luck, I will be doing the tech-line dance before long as well.

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BTW - cutoff switch in my car is on th eground side as I felt that was safer in th eevent of an accident. However in testing I found that it doesn't cut power to the car. I believe the alternator is putting out enough juice to run things up front so if you're considering this setup be aware that you'll likely need a relay on the alternator (sigh) icon_sad.gif All the techs will care about is that the motor dies when they hit the switch IMO. The Summit aluminum battery box is what I used mounted just ahead of the rear tires in the center between the cargo bins. I used a lightweight battery and did this in order to put the weight where it might assist handling as opposed to acting as a pendulum way in the back...

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Hey BLKMGK, Thanks icon_smile.gif

I was hoping for insight on the specific question (which I'm getting) and in the course of answering it you also provide me a with the solution to my battery "not so" shut off switch on my Chevelle.

 

Battery in the trunk, bulkhead, shut off switch, ford soleniod-works great to cut the juice for electrical work BUT doesn't serve the intended purpose.

 

Thanks for the idea.

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Jim,

 

How about this to make the Alternator get taken out of the circuit with the cutoff switch off:

 

- Wire one side of the coil of a relay to a key switched +12V

 

- Wire the other side to the OUTPUT of your ground cutoff switch

 

Now, the relay will only be energized if the key is on and the cutoff switch is switched on (ground going to the output of the switch, the rest of the car, and the relay).

 

- Wire the relay NO contact and arm contacts (86 and 87? on a VF40 relay?) inline to the field energizer wire (the one an idiot light would be on) of your alternator.

 

(If you have a 1 wire alternator, I don't think you can do this, since it makes that field connection internally with the output lug. Of course, you could put a huge relay on the alternator output to solve this, but that'd be a stretch.)

 

Now the alternator only gets it's field coils energized if the key is on and the cutoff switch is on.

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Slow down guys-take me through this slowly cause apparently I'm a little electrically challenged.

 

Here's the set up:

Battery in the truck

Master cut off switch on the rear trunk panel on the +

2o welding led for a battery cable to Ford solenoid mounted on passanger firewall

Battery led connects to "A" side of solenoid

MSD 6AL box (coil connected to box)gets main power from "A" side of solenoid

MSD box only hot when key is in Start or On position

Altenator is a 63A internal regulator w/#1(main led) & #2(excitor wire) connected via small gauge wire

Main altenator led (#1) goes back to "A" side of the solenoid

Volt gauge connected in normal fashion

 

FYI Electric fuel pump with low oil pressure shut off switch.

 

All works fine (charging, starting) UNTIL, I Kill the battery switch and it still keeps running.

 

Help, and please talk slow!

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How is the #2 exciter wire connected into the car? If it's running to the same place as the #1 output wire, that's the problem - it's always hot - but then you'd be draining the battery all the time when the car is off, so I doubt that's the case.

 

If that #2 wire is connected to a key-switched circuit (as it should be, with an idiot light or a resistor), then the problem is that even when you switch off the cutoff switch, the #2 wire is feeding back through the other circuits that get fed by the ignition switch to power the ignition. You can solve that with a diode or a relay that cuts the the connection to the alternator exciter wire.

 

Hope that helps

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Guest Anonymous

Hey Guys,

What about installing the master cut off swith on the groung side of the battery. Wouldn't that disconnect the power completely and you won't fry your alternator if the engines running and you try to cut the positive side and full field the alternator.

 

Glenn

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Glenn,

 

That's what BLKMGK (Jim) did. He still had the problem of turning off the cutoff switch and the car still running. That's because it was running off of the alternator, probably through a sneak circuit from the key switch. I was trying to lay out a method for isolating the alternator exciter (field) connection to power with a relay to keep the sneak circuit in check.

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Larry,

 

I solved this problem, car still runs when cutoff switch is turned off, on my drag race only '72 Nova by connecting the "Battery" terminal on the alternator to the battery side of the cutoff switch. I had to run a long wire since the battery and cutoff switch are mounted in the back, but it solved the problem.

 

Regards,

Don

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