23 replies to this topic

[Chad Martin]

I'm curious what amount of rewiring is allowed in SM competition. There is really no mention of it in the NASA rules. This would be for both NASA and SCCA competition and possibly even NASA national championships.

For the RX-7 racecar I built I removed much of the stock wiring except for the emissions harness. And in that case i removed all the wires no longer used. I removed all the fuse boxes and made the car completely fuseless. Just used maybe half a dozen circuit breakers all within reach of the driver. A miata in this regard seems to be a simpler animal but I still like the idea of getting rid of all the unnecessary wiring for reliability and ease of troubleshooting. Plus making all the connectors simpler, more solid, and all completely waterproof.

Could a car that had had the wiring completely gutted and re-engineered / rewired be DQed?

[davew]

First rule of Spec Miata

If it does not say you, you can not.

[CruzanTom]

From the Preliminary Minutes published today:


Spec Miata
1. #8273 (Chuck Dawson) Wire Harness Repair
Thank you for your letter. SM wiring harness repair falls under 9.1.8.C.4.K: k. All
chassis/structural/electrical repairs, if performed, shall be in concurrence with factory procedures,
specifications, and dimensions. Unless specifically authorized by the manufacturer for repair or
allowed by these rules, no reinforcement, i.e., seam welding, material addition, etc., is permitted.

See http://scca.cdn.race...lim.minutes.pdf

[Brocodile]

From the Preliminary Minutes published today:


Spec Miata
1. #8273 (Chuck Dawson) Wire Harness Repair
Thank you for your letter. SM wiring harness repair falls under 9.1.8.C.4.K: k. All
chassis/structural/electrical repairs, if performed, shall be in concurrence with factory procedures,
specifications, and dimensions. Unless specifically authorized by the manufacturer for repair or
allowed by these rules, no reinforcement, i.e., seam welding, material addition, etc., is permitted.

See http://scca.cdn.race...lim.minutes.pdf

Nice catch, Tom.

[Chad Martin]

First rule of Spec Miata

If it does not say you, you can not.

Right, and of course the difference between the fast cars and the mid-pack cars is rules vs enfocement.

[Ron Alan]

Right, and of course the difference between the fast cars and the mid-pack cars is rules vs enfocement.

Being new, most will let you slide on this. I would say as a whole SM is pretty self policed with minimal tech. For the most part, the difference between mid-pack and the pointy ends are the nuts behind the wheel and the grip on the pavement(tires and set up). I would say blatant cheating is minimal and things that may not be legal don't usually make up for a lack of talent. Have seen a few videos were a lapper being passed, wins a drag race with the race leader until they both hit the braking zone

To correct Dave...IF IT DOES NOT SAY YOU CAN, YOU CAN'T This is the law of SM

c

[Chris70]

And where does it say you can paint your car other than factory original color ? :-) LOL

[davew]

It used to. But I could not find it in the SM section. I did find it in the SS section


E. Vehicle Preparation

Appearance shall be neat and clean. Automobiles that are dirty
either externally or in the engine or passenger compartments, or
that show bodywork damage or that are partially or totally in primer,
or that do not bear the prescribed identification marks shall not be
approved for competition. Vehicles may be painted any color(s).



MEATHEAD where are you???

Dave

[Keith Novak]

...or that show bodywork damage...shall not be approved for competition.

Fortunately they're a bit lenient on that part.

[LarryKing]

Or unfortunately.

[Chad Martin]

Being a Chief Scrutineer for NASA (and an licensed engineer) and now having some hands on time with a SM I own and others, I am less than thrilled with how most of them are wired with respect to safety, not only from the factory, but in race trim with kill switches installed...even "properly".

Realistically in Miata's there should be circuit protection in the trunk, at the battery as well as an additional one in the engine bay at the alternator if not using the stock wiring for the alternator.

The battery is in the back yet there is no circuit protection until the fuse box in the engine bay in stock form? Even in race trim the way some wire in kill switches there ends up being no circuit protection what so ever between the battery and alternator. When us RX-7 guys relocate our batteries to behind the passenger seat area it is very common practice to have a 120-150A circuit breaker at the battery and another one installed under the hood protecting the alternator. Why is this important?

http://www.youtube.com/watch?v=i-vhTazgdlA Go to 5:48 (It is not me driving)

Yep that's my car two weeks after purchase nearly going up....as with most things a culmination of issues and oversight by the previous owner and ultimately me for putting it on track in this condition caused this. Upon looking at the damage and in retrospect:

1. No circuit protection at the battery, once the kill switch was thrown the short was still present.

2. A sub-par kill switch and wiring configuration of the kill switch such that the circuit between the battery and alternator was still open when the kill switch was thrown. This kill switch was the simple type that had no ignition interrupt or resisted ground for alternator protection.

3. Alternator wire (as wired by the previous owner) was too small, had no circuit protection, and the wire was no tied down properly. This alternator wire was run all the way back to the hot (battery) side of the kill switch on the passenger B-pillar, with no circuit protection between. This was the wire that shorted, and started on fire and continued to burn after the kill switch was thrown. Luckily i had replaced the positive terminal on the battery with a marine style terminal including a wing nut thus the car didn't burn down.

4. In my annual tech inspection of the car I assumed that the small alternator wire was actually the alternator protection grounding wire. Since the CCR required kill switch terminal 'covers' was actually a bunch of electrical tape making it impossible to check and see how the kill switch was actually wired without cutting all the tape off (which i should have done).

In reading around forums including these this seems to be "the way it's done" for a lot of folks. It really is a poorly conceived way to wire a kill switch at best and at worst without protecting the extended alternator wire AND the battery cable at the battery is dangerous. The 'instructions' i've found also reference using a 12-10 gauge wire for the alternator wire extended to the switch. Folks, miatas have at worst a 60amp alternator. 12ga wire wont carry 60 amps and 10ga gives almost no safety factor. Run 8ga at least or, wire a proper switch and you wont have to run that wire back to the switch.

Since these are safety items I will be revising them; replacing the cheapo kill switch with a proper 4430 kill switch including separate ignition cuttoff and alternator protection, adding the circuit breakers to my car and will not be flagging any such modifications in my region to spec cars. Really it should be required by the NASA CCR that any battery placed in the cabin or in the trunk should have circuit protection within 18" of the battery. Further electrical tape should not be an approved terminal "cover" for batteries, starters, alternators, and kill switches. I plan to submit this info to the national office as such and we will see where it goes.

In my case it was ultimately my failure for not going through the car with a fine tooth comb prior to putting it on track. That mistake wont be made again and I will closely look at these same cars for the same possible issues.

If anyone has any questions on this i'm happy to help. I guess i should never be surprised by what people try to get past tech....and in this case did.

[MPR22]

Being a Chief Scrutineer for NASA (and an licensed engineer) and now having some hands on time with a SM I own and others, I am less than thrilled with how most of them are wired with respect to safety, not only from the factory, but in race trim with kill switches installed...even "properly".

Realistically in Miata's there should be circuit protection in the trunk, at the battery as well as an additional one in the engine bay at the alternator if not using the stock wiring for the alternator.

The battery is in the back yet there is no circuit protection until the fuse box in the engine bay in stock form? Even in race trim the way some wire in kill switches there ends up being no circuit protection what so ever between the battery and alternator. When us RX-7 guys relocate our batteries to behind the passenger seat area it is very common practice to have a 120-150A circuit breaker at the battery and another one installed under the hood protecting the alternator. Why is this important?

http://www.youtube.com/watch?v=i-vhTazgdlA Go to 5:48 (It is not me driving)

Yep that's my car two weeks after purchase nearly going up....as with most things a culmination of issues and oversight by the previous owner and ultimately me for putting it on track in this condition caused this. Upon looking at the damage and in retrospect:

1. No circuit protection at the battery, once the kill switch was thrown the short was still present.

2. A sub-par kill switch and wiring configuration of the kill switch such that the circuit between the battery and alternator was still open when the kill switch was thrown. This kill switch was the simple type that had no ignition interrupt or resisted ground for alternator protection.

3. Alternator wire (as wired by the previous owner) was too small, had no circuit protection, and the wire was no tied down properly. This alternator wire was run all the way back to the hot (battery) side of the kill switch on the passenger B-pillar, with no circuit protection between. This was the wire that shorted, and started on fire and continued to burn after the kill switch was thrown. Luckily i had replaced the positive terminal on the battery with a marine style terminal including a wing nut thus the car didn't burn down.

4. In my annual tech inspection of the car I assumed that the small alternator wire was actually the alternator protection grounding wire. Since the CCR required kill switch terminal 'covers' was actually a bunch of electrical tape making it impossible to check and see how the kill switch was actually wired without cutting all the tape off (which i should have done).

In reading around forums including these this seems to be "the way it's done" for a lot of folks. It really is a poorly conceived way to wire a kill switch at best and at worst without protecting the extended alternator wire AND the battery cable at the battery is dangerous. The 'instructions' i've found also reference using a 12-10 gauge wire for the alternator wire extended to the switch. Folks, miatas have at worst a 60amp alternator. 12ga wire wont carry 60 amps and 10ga gives almost no safety factor. Run 8ga at least or, wire a proper switch and you wont have to run that wire back to the switch.

Since these are safety items I will be revising them; replacing the cheapo kill switch with a proper 4430 kill switch including separate ignition cuttoff and alternator protection, adding the circuit breakers to my car and will not be flagging any such modifications in my region to spec cars. Really it should be required by the NASA CCR that any battery placed in the cabin or in the trunk should have circuit protection within 18" of the battery. Further electrical tape should not be an approved terminal "cover" for batteries, starters, alternators, and kill switches. I plan to submit this info to the national office as such and we will see where it goes.

In my case it was ultimately my failure for not going through the car with a fine tooth comb prior to putting it on track. That mistake wont be made again and I will closely look at these same cars for the same possible issues.

If anyone has any questions on this i'm happy to help. I guess i should never be surprised by what people try to get past tech....and in this case did.

Oh my. His exit technique needs some work, if that car had a fuel fire he might have panicked and tried to exit via the trunk. Seriously please he needs to work on the exit and if your driver door doesn't open, FIX IT.

Edited by MPR22, 11-26-2012 04:48 PM.

[HoneyBadger - BrianW]

Oh my. Your exit technique needs some work, if that car had a fuel fire you might have panicked and tried to exit via the trunk. Seriously please work on your exit and if your driver door doesn't open, FIX IT.

In fairness... he did indicate that it wasn't him that was driving the car. But I agree, there is a door for a reason.

[MPR22]

In fairness... he did indicate that it wasn't him that was driving the car. But I agree, there is a door for a reason.

Thanks, missed the part where he said he wasn't driving.

[KentCarter]

Eek... the way his HANS keeps getting hooked... and the cool suit lines.... and and

[Jim Drago]

[Chad Martin]

In this particular car the door bars are as high as the sill of the door itself so the opening is no better with the door open. No, not ideal and likely will be changed. It's also his first weekend in the car period.

[LarryKing]

How did the driver pass NASA's 10 second exit rule? (I'm guessing he wasn't tested)

[Chad Martin]

It's 15 seconds if you don't open the door and use the window opening. He was tested and passed.

[LarryKing]

Once again NASA's logic escapes me.