Group 5 black flag @ ORP

As I posted in facebook ...
My new car will have two kill switches -- one on either side of the car between the A-piller and the FIA bar.
You can have two switches if you wire them in series and use largish master solenoids to handle run/charge loads.
By having the crank circuit separate from the run circuit the wire size of the run/charge circuit to the master solenoid is much smaller.
I have nothing over 8 gauge wire (fused) that is actively energized after crank is complete.
Some people hate solenoids, I love 'em.

On my circuit switch panel (remote mounted next to the seat) I can a) kill all run circuits 2) kill the fuel pump alone
3) have an inertia switch for the EFI fuel pump as well.
The fuel cell/ dry sump will have its own cage.
I've had previous episodes with gasoline and fires that makes me extremely paranoid of this in a car. Can you tell?

I also run a fire system and a separate bottle in my present car and will do the same in the new one.
 
Something to consider, too, is wire routing. The first car, which I did not build,
had the switch just inside driver's window-
which seemed like a great idea, except that in the event of any crushing hit to the shell,
all those hot wires are right in my lap. And only half are switched...

The second car's 98% stock, and the battery wire runs down the right side rocker panel.
So that switch is right inside the passenger window, high enough to be
easily visible, and I can hit it if I loosen, but not release, the harness.


While we're at it, how easy (and obvious) is your window net release?

Agreed, great thread.

t
 
Something to consider, too, is wire routing. The first car, which I did not build,
had the switch just inside driver's window-
which seemed like a great idea, except that in the event of any crushing hit to the shell,
all those hot wires are right in my lap. And only half are switched...

The second car's 98% stock, and the battery wire runs down the right side rocker panel.
So that switch is right inside the passenger window, high enough to be
easily visible, and I can hit it if I loosen, but not release, the harness.


While we're at it, how easy (and obvious) is your window net release?

Agreed, great thread.

t

Funny you mention that, after seeing a Pro team do something similar, I wrapped the release for my window net in red tape a few seasons ago. Makes it a little easier to see from both the inside and outside.

Also, your point about wiring is very valid. The E30's do have the nice feature of the main hot running down the opposite side of the driver. But in the case of the video, that might not have been the best location for the only kill switch (since the fire was being blown in to that same location.) My own is set up in the same place as well, but I am now considering finding a better location or installing a second switch some where else that perhaps uses a solenoid to activate.

Back in my drag racing days, it was common to actually mount the kill switch in the tail lights, so that in theory if you put the car in to the wall, a safety crew could walk up behind you and kill the battery. This may be another place to consider, though it wouldn't alleviate the jerk/thinks their funny people problem.

What is the safety crews thoughts?
 
......Back in my drag racing days, it was common to actually mount the kill switch in the tail lights, so that in theory if you put the car in to the wall, a safety crew could walk up behind you and kill the battery. This may be another place to consider, though it wouldn't alleviate the jerk/thinks their funny people problem. What is the safety crews thoughts?

That would mean a major retraining of all the turn worker/safety personnel. There's a good chance many would forget when approaching their 1st few incidents after the change. And, on open wheel cars that would put the off switch right near the engine which could be on fire itself.

On the other hand, it does have merits.
 
Rusty has a switch mounted just outside the left A-pillar (Not the key type) and another mounted on a small plate welded to the center upright just up and behind the driver's head. On board system is a pull cord with R-clip for security.

After a roll-over like that, I am not at all surprised that the on-board system was trumped by escape.

As the season continues it is never a bad idea to re-assess and consider if there were any short cuts taken to prep the car in the off season. New seat? New window net? New belts? New master brake cylinder??

What direction is that R-clip facing, and how easy is it to grasp in a hurry with gloves on?

And it's always nice to have the driver's help to extinguish his car, but after an E-ticket ride like that, the next best step is to have a chat with our boys wearing the blue uniforms. Thanks for the thought.
 
Still not sure what failed but I did find this in service manual which is a bit concerning.
master_vac.jpeg

  • Vacuum line is intact and doesn't leak with a vacuum pump.
  • Vacuum line didn't collapse with the pressure my hand pump could create.
  • Check valve(didn't know this existed) seems to work. Holds pressure on one end and lets air through the other.
  • Master-vac holds pressure. Haven't gotten this apart yet.
  • Calipers aren't seized.
  • Brake pads look healthy. Lots of life left no chunking/glazing. Pads were new for the session and calipers were new(O'reilly's rebuilt) for the weekend.
  • Pulled the seat and there's no tools or anything that could've blocked the pedal. Lied down in the car and mucked with the pedal and couldn't get it to bind or anything.


Not related to the failure but turns out the Z originally had a light that would warn you if the difference between the brake pressure in the front and rear was too great. Kinda of interesting.

Engine compression on cylinders 3 & 4 is low. 80psi and 145psi vs 150-175 on the rest of the cylinders. Added oil to cylinder 3 and redid the compression test and the pressure stayed the same so maybe it's the head gasket or the head was warped by the fire. Retorqued the head and readjusted the valves on cylinder 3 hoping for a miracle but no.
 
I've done it. Sometimes that's the safest side of the car for me to communicate with a driver. I'm not putting my butt in traffic to have a leisurely conversation with anyone strapped into a cage. I'll yell. No problem.
 
Still not sure what failed but I did find this in service manual which is a bit concerning.
View attachment 1420

  • Vacuum line is intact and doesn't leak with a vacuum pump.
  • Vacuum line didn't collapse with the pressure my hand pump could create.
  • Check valve(didn't know this existed) seems to work. Holds pressure on one end and lets air through the other.
  • Master-vac holds pressure. Haven't gotten this apart yet.
  • Calipers aren't seized.
  • Brake pads look healthy. Lots of life left no chunking/glazing. Pads were new for the session and calipers were new(O'reilly's rebuilt) for the weekend.
  • Pulled the seat and there's no tools or anything that could've blocked the pedal. Lied down in the car and mucked with the pedal and couldn't get it to bind or anything.


Not related to the failure but turns out the Z originally had a light that would warn you if the difference between the brake pressure in the front and rear was too great. Kinda of interesting.

Engine compression on cylinders 3 & 4 is low. 80psi and 145psi vs 150-175 on the rest of the cylinders. Added oil to cylinder 3 and redid the compression test and the pressure stayed the same so maybe it's the head gasket or the head was warped by the fire. Retorqued the head and readjusted the valves on cylinder 3 hoping for a miracle but no.

Mr. Hedges, it is so good that you were unhurt. Fire is the single most feared threat for racers. Fortunately I have never had to endure a fiery crash. It does look like your car launched quite high, before taking the tumbles. A nasty wreck, to be sure.

In the first couple of seasons I ran my Z boiling brake fluid was something that troubled me greatly, especially at Westwood. I would get about 10 minutes into a race and have the pedal go soft. I found that I would need to gently pump the brakes with my left foot before getting into the braking zone. I also found that if I didn't get them pumped up enough the pedal would be on the floor before I had slowed the car down enough to make the turn in.

This always resulted in agricultural racing, grass mowing and gravel collecting.

After many different configurations of air ducting and master cylinder replacements I found the perfect setup that gives the car brakes that last the entire weekend without the need to bleed them after every track session, a pedal that is hard, and there first time, every time.

I also eliminated the vacuum booster, and installed a dual master cylinder setup with and adjustable balance bar.

Another issue I found was the motor mounts failing. Brand new mounts fresh from the local Nissan dealer would separate after one weekend of running hard. I ultimately fabricated solid mounts, which solved that problem. If solid mounts are not permitted in your class perhaps a simple chain limiter could be used to keep the engine relatively close to the mount when it fails.

I see that you are running ITS, and as I am unfamiliar with the prep rules for that class I don't know if you can make those types of changes to the brakes and engine mounts, but it would be worth looking into.

As others have commented, a switch operated by the engine oil pressure to kill the fuel pump(s) is essential for safety in the event of a crash. When I got my Z in 1989 it had been a Conference race car for 10 years. The car had been run with a bolt in roll bar (simple hoop, nothing else) the stock fuel tank, and had nothing to ensure safety. I completely rebuilt the car, stripping it to the bare shell. A full cage was added, as well as a fuel cell, with multiple pumps, a surge tank, and the oil pressure cut off switch.

I also added a battery disconnect. At the time the location was recommended to be as close as possible the the battery with the shortest possible run between the positive terminal and the switch. Since the battery on a Z is at the right rear corner of the engine bay I mounted the switch in the center of the inspection door directly above the battery. This leaves only about 10 inches of cable energized after the circuit has been opened. In the more than 20 years of racing since and several off course excursions there never has been a problem for turn workers getting to it to shut the power off.

I know in your situation with the wind carrying the flames across that side of the car the switch would have been impossible to reach, and seeing the video has given me ideas for a remote activation location, like with a cable, from the left side of the car. Hopefully, should the need ever arise, then the power could be shut off from either side of the car.
 
I've done it. Sometimes that's the safest side of the car for me to communicate with a driver. I'm not putting my butt in traffic to have a leisurely conversation with anyone strapped into a cage. I'll yell. No problem.

There you go!

In fact, it may have even been you on one of the rare occasions that I required the able assistance from your crew! Either way, we racers can never give enough thanks for your hard work and dedication.

So again, thank you for all you do.
 
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