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Bill Strong

What happened to your ChampCar today? - 2020

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2 hours ago, SonsOfIrony said:

 

Correct.  I'm not a fan of a giant unfused power cable running the length of the car.

 

what size is that bad boy breaker?

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1 hour ago, SonsOfIrony said:

Correct.  I'm not a fan of a giant unfused power cable running the length of the car.

I'm going to get flamed for this , going to keep it short.

 

As a tech, life long class D racer and demo derby champ, it is darn near impossible to wrap my head around fusing the starter,  +90% of the time a fused setup will work till you have a off day, say the car spins/stalls/floods, now, a perfect storm,  extended crank time+ hot draggy engine+hot starter+ low battery= greatly increased current requirement...

Best case, you waste a couple minutes scrambling to reset the breaker...Worse case, PoP goes the breaker while sitting sideways in the middle of the track.

 

OEM wiring has up to a 150a fuse in the charge circuit, none for the start, put that breaker on the alternator, if safety is paramount, I would then double the starter breaker spec to avoid randomly sitting mid track without power a year down the road when that storm successfully brews.

 

 

 

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4 hours ago, Team Infiniti said:

I'm going to get flamed for this , going to keep it short.

 

As a tech, life long class D racer and demo derby champ, it is darn near impossible to wrap my head around fusing the starter,  +90% of the time a fused setup will work till you have a off day, say the car spins/stalls/floods, now, a perfect storm,  extended crank time+ hot draggy engine+hot starter+ low battery= greatly increased current requirement...

Best case, you waste a couple minutes scrambling to reset the breaker...Worse case, PoP goes the breaker while sitting sideways in the middle of the track.

 

OEM wiring has up to a 150a fuse in the charge circuit, none for the start, put that breaker on the alternator, if safety is paramount, I would then double the starter breaker spec to avoid randomly sitting mid track without power a year down the road when that storm successfully brews.

 

 

 

This is a wiring fix I am making currently...

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4 hours ago, Team Infiniti said:

I'm going to get flamed for this , going to keep it short.

 

As a tech, life long class D racer and demo derby champ, it is darn near impossible to wrap my head around fusing the starter,  +90% of the time a fused setup will work till you have a off day, say the car spins/stalls/floods, now, a perfect storm,  extended crank time+ hot draggy engine+hot starter+ low battery= greatly increased current requirement...

Best case, you waste a couple minutes scrambling to reset the breaker...Worse case, PoP goes the breaker while sitting sideways in the middle of the track.

 

OEM wiring has up to a 150a fuse in the charge circuit, none for the start, put that breaker on the alternator, if safety is paramount, I would then double the starter breaker spec to avoid randomly sitting mid track without power a year down the road when that storm successfully brews.

 

 

 


First off, hot engines are not draggy. Crank time does not increase current requirement. If your battery is low after stalling an engine then your alternator is not working.

In that case, if you pop the breaker, sounds like it's working as it should and cuts off flow before you heat up that cable so much you start somethign on fire. A properly sized breaker will not pop under usual the range of expected starting circumstances.

We should just get rid of fuses too!

:)

Edited by Slugworks Paul
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14 minutes ago, Slugworks Paul said:


First off, hot engines are not draggy. Crank time does not increase current requirement. If your battery is low after stalling an engine then your alternator is not working.

In that case, if you pop the breaker, sounds like it's working as it should and cuts off flow before you heat up that cable so much you start somethign on fire. A properly sized breaker will not pop under usual the range of expected starting circumstances.

:)

Wire your car as you like but your not a SBF/SBC/BBF guy are you?  Those things can drag a ton of amps after a hot soak, honestly a properly sized battery wire will  get hot, smoke a end but not catch fire with a stalled starter or I personally would have burned dozens of cars.

 

Plenty of other things can increase cranking amp demand, a low battery happens after rolling a engine over for a bit, have you ever accidentally rolled a starter over with the car in gear? Had runoff gravel temporarily get between your starter and ring gear? A un-fused starter would pulverize a piece of gravel or drive a car with no worry.

 

 

 

 

I had the same opinion before ever actually encountering it first hand.

 

Edited by Team Infiniti
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42 minutes ago, Team Infiniti said:

Wire your car as you like but your not a SBF/SBC/BBF guy are you?  Those things can drag a ton of amps after a hot soak, honestly a properly sized battery wire will  get hot, smoke a end but not catch fire with a stalled starter or I personally would have burned dozens of cars.

 

Plenty of other things can increase cranking amp demand, a low battery happens after rolling a engine over for a bit, have you ever accidentally rolled a starter over with the car in gear? Had runoff gravel temporarily get between your starter and ring gear? A un-fused starter would pulverize a piece of gravel or drive a car with no worry.

 

 

 

 

I had the same opinion before ever actually encountering it first hand.

 


More amps than a cold start at -25F? I very much doubt it. 

I've run a similar breaker in all of my 3 cars now for over 10 years. I've had one pop repeatedly once, and it was because the replacement engine I installed had serious problems causing tons of engine drag, outside of the norm. The breaker did it's job and informed me of that problem and prevented collateral damage had I been silly enough to ignore it and try to run the engine anyway.

In any case - if a certain condition is normal for your engine, size your breaker accordingly (as long as it is below the current threshold for a short to ground, you've still got a valid safety measure). Mine are large enough that even extended cranking on a low charge battery will not trigger it. When it does pop, you know something 'out of the norm' has occurred. And yes, I do consider stalling on track to be a normal condition, though maybe not the most favorable :)

I guess my theory is if there are underlying problems (gravel getting in your bell housing, car doesn't start when hot, excessively tight bearing clearances, etc) I tend to address those issues before bypassing safety measures to band-aid a condition caused by that issue.

Edited by Slugworks Paul
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5 hours ago, Team Infiniti said:

Wire your car as you like but your not a SBF/SBC/BBF guy are you?  Those things can drag a ton of amps after a hot soak, honestly a properly sized battery wire will  get hot, smoke a end but not catch fire with a stalled starter or I personally would have burned dozens of cars.

 

Plenty of other things can increase cranking amp demand, a low battery happens after rolling a engine over for a bit, have you ever accidentally rolled a starter over with the car in gear? Had runoff gravel temporarily get between your starter and ring gear? A un-fused starter would pulverize a piece of gravel or drive a car with no worry.

 

I had the same opinion before ever actually encountering it first hand.

 

 

I didn't size the breaker based on gut feelings and guesses.  I used math, and should be able to survive any worst case scenario besides a shorted main cable.

 

The factory battery cables were 4 gauge, which has an average safe load capacity of give or take 100 amps.

 

The thermal breaker I selected is rated for 150 amps.  The 2 gauge cable I selected is rated for 190 amps.

 

Until I find myself in a situation that would have melted the factory cable, the breaker should not trip.

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Hyundai 4 banger, skip to 3:18 for the test:

 

https://autoditex.com/page/relative-compression-test-67-1.html

Note the 475 amp spike at the beginning of the test even with a 4 cylinder.

 

Old mechanics like Ed and me have known about relative compression tests for a long time. Disconnect the coil, crank it and listen for the lunge in starter rpm.

 

We've also seen some pretty high amp starting systems in our day. :)

Edited by mender
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If you don't want the long run of starter cable hot all the time you can use a remote starter solenoid. $10ish online, $Free from a junkyard Ford if you're wearing your cargo pants. That will require a second cable to power the car, but you can put your fuse on it and not worry about popping it turning the starter over. 

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First day in the garage with the new car ($750 E39 BMW). Mostly just inspecting it and seeing whats what. Happy to find no major defects, and anything I found needing repair and replacement are already items I budgeted for or will be removing from the vehicle anyhow. 

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4 hours ago, RandomTask said:

Figured this was applicable to a lot of people on here....

FB_IMG_1586484802131.jpg

Need to color in all the gears, that was the ring gear...

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4 hours ago, mender said:

Need to color in all the gears, that was the ring gear...

 

It floors me how many people make/distribute memes with such blatant errors.

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58 minutes ago, thewheelerZ said:

☝️These guys: fun at parties. 

 

I don't get invited to parties to be honest....

 

Might be a correlation there.  Meh, just means more time for race car.

  • Haha 5

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On 3/30/2020 at 6:44 PM, SonsOfIrony said:

 

I didn't size the breaker based on gut feelings and guesses.  I used math, and should be able to survive any worst case scenario besides a shorted main cable.

 

The factory battery cables were 4 gauge, which has an average safe load capacity of give or take 100 amps.

 

The thermal breaker I selected is rated for 150 amps.  The 2 gauge cable I selected is rated for 190 amps.

 

Until I find myself in a situation that would have melted the factory cable, the breaker should not trip.

 

You won't have any issues, like Paul I have been running the same breaker shown in the pic and so far in four years use it has never tripped.  Not sure why these guys are hung up on the use of a breaker.  It is a safe way to protect the cable, like any breaker.  Sure, you will have inrush current for the starter motor, but the breaker will take that.  Good job.

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15 minutes ago, Burningham said:

Not sure 

Because I have experienced this on track before?

 

 One size does not fit all. 

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