AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
2/25/24 3:00 p.m.

Since a kill switch is a required safety item when relocating battery, is the kill switch budget exempt?

I would argue no, since relocating battery is optional. However, I have to ask because I'm getting close to my budget cap.

gumby
gumby GRM+ Memberand Dork
2/25/24 6:24 p.m.

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
2/25/24 6:42 p.m.

But what if I really want it to be?

Tom Suddard
Tom Suddard GRM+ Memberand Publisher
2/25/24 9:43 p.m.

Nice try. No. 

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) GRM+ Memberand UltimaDork
2/25/24 9:48 p.m.

BTW, I'm pretty sure that it can't be a plastic one according to NHRA tech rules.

Stampie
Stampie GRM+ Memberand MegaDork
2/25/24 10:05 p.m.

In reply to Floating Doc (Forum Supporter) :

We realize that the NHRA rulebook has a few issues when it comes to this event. The following exceptions will be granted if your car runs slower than 11.49 E.T.:

  • Battery shutoff switches may be of alternative construction and placement. Must remain within first responder's reach and be clearly labeled on the exterior of the vehicle.

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
2/26/24 3:12 p.m.
Stampie said:

In reply to Floating Doc (Forum Supporter) :

We realize that the NHRA rulebook has a few issues when it comes to this event. The following exceptions will be granted if your car runs slower than 11.49 E.T.:

  • Battery shutoff switches may be of alternative construction and placement. Must remain within first responder's reach and be clearly labeled on the exterior of the vehicle.

i'm mounting mine high on the dash and providing a push/pull actuator rod with T-handle on each end, so it can be actuated from either side of the car.  One side will be labeled "PUSH OFF" and the other side, which i will call the Stampie side, will be labeled "PULL OFF".

Stampie
Stampie GRM+ Memberand MegaDork
2/26/24 3:27 p.m.

In reply to AngryCorvair (Forum Supporter) :

Thank's for renewing the OnlyFans subscription.

Bigben
Bigben HalfDork
3/2/24 1:59 a.m.

After going through all the work to relocate my battery I read the NHRA requirements and decided it wasn't worth the hassle or the budget costs, so I just put it back in the stock location. 

rich911s
rich911s Reader
3/2/24 7:00 p.m.

I know the budgets tight, but we cobbled one together and it's been flawless so far.   Bought the two items below from beezoz and drilled a hole at the very end of the lever, connected it to the T-handle with a key ring.  Basically we copied the one we saw on Jegggs for $65 for only $25.   

 

 

JEGGGSS unit:

MiniDave
MiniDave HalfDork
3/3/24 3:29 p.m.

Are those switches really heavy duty enough for the amps a starter motor pulls? Just curious. 

Also, do you disconnect the hot side or the ground side? (Project Binky did the ground side)

rich911s
rich911s Reader
3/3/24 5:36 p.m.

Yes, so far so good.  The switch we bought says it will handle 250 amps, but notice the Jegggs only says 125 amps.  We hooked it to the Hot as that is what the NHRA rules say to do.     

Stampie
Stampie GRM+ Memberand MegaDork
3/3/24 8:10 p.m.

In reply to MiniDave :

You should never disconnect the ground side.  If your engine is still running the alternator will still power the car.  It gets it's ground from it's case bolted to the engine. It doesn't get ground from the battery.

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) GRM+ Memberand UltimaDork
3/3/24 11:03 p.m.

In reply to Stampie :

I hadn't thought of that.  It did occur to me that if the hot side got shorted out somewhere, switching off the ground isn't going to keep it from burning. 

Ranger50
Ranger50 MegaDork
3/6/24 8:31 a.m.

You are always better off, at least looking at it as a safety side problem, that the cutoff switch should NOT be cutting off the main power directly. I did it and got away with it. But having to research and research and some more research, the cutoff should be used to turn off another switch/relay that can handle 200+ amps. The alternator should be wired into the battery/pre relay/switch side of the cutoff. If you don't the switch is useless, as the alternator keeps powering everything.

SV reX
SV reX MegaDork
3/6/24 9:28 a.m.

IIRC, NHRA says the cutoff switch should cut off both the battery and the alternator. 

maschinenbau
maschinenbau GRM+ Memberand PowerDork
3/6/24 9:43 a.m.

Yep, per NHRA if you move the battery at all, you must have a kill switch accessible from the rear that kills power between engine and battery/alternator. Which means you need two giant long cables from engine bay to the switch. Here's how I did it on Datsaniti using a custom pushrod through a hole in the body near taillight. I also added a second kill switch in series for the dashboard, so I could kill power from the driver's seat too. The alt and battery positive are one side of the switch lugged together. Either kill switch kills the engine, but theoretically the alt would still charge the otherwise isolated battery. You can also buy a 4-terminal cutoff switch that has a separate circuit that isolates the alternator power from the battery. 

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/datsaniti-1980-datsun-210-wagon-vq35-swap-2018-cha/138776/page9/

 

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
3/6/24 10:50 a.m.

In reply to maschinenbau :

there's a Challenge-specific exclusion to the switch placement requirement:

https://2000challenge.com/rules states, under the Safety heading:

We realize that the NHRA rulebook has a few issues when it comes to this event. The following exceptions will be granted if your car runs slower than 11.49 E.T.:

>>snip<<

  • Battery shutoff switches may be of alternative construction and placement. Must remain within first responder's reach and be clearly labeled on the exterior of the vehicle.

so I'm good as long as i pedal the car to avoid cracking 11.50

Stampie
Stampie GRM+ Memberand MegaDork
3/6/24 11:13 a.m.

In reply to AngryCorvair (Forum Supporter) :

You've proven that you have no issues going only half throttle.

maschinenbau
maschinenbau GRM+ Memberand PowerDork
3/6/24 11:38 a.m.

In reply to AngryCorvair (Forum Supporter) :

This guy really thinks he has an 11 second car wink

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