Firewall

[Jess_a]

Hello All
We are having a serious doubt with the firewall. The properties of the firwall and accumulator container are the same. So do we need to use a firewall in front of the accumulator container as well?

[BrettAM]

T4.5 Firewall
T4.5.1 A firewall must separate the driver compartment from all components of the fuel supply, the engine
oil, the liquid cooling systems and any high voltage system (PART EV - EV1.1). It must protect the
neck of the tallest driver. It must extend sufficiently far upwards and/or rearwards such that any point
less than 100 mm (4 ins.) above the bottom of the helmet of the tallest driver shall not be in direct line
of sight with any part of the fuel system, the cooling system or the engine oil system.

In Michigan, we had to make a last minute addition to the side of our car to prevent this line-of-sight. We were able to use a CF panel, though.

[Jess_a]

In our case the top of the accumulator container is also made up of firewall material. So between driver's neck and accumulator there is a firewall material. Will it serve the purpose to prevent this line of sight?

[BrettAM]

The material of your accumulator is irrelevant. If your accumulator were to leak or puncture, would there be line of sight to the driver?

[Canuck Racing]

I agree with you Brett, but from a rules standpoint if the accumulator isn't part of "the fuel supply, the engine oil, the liquid cooling systems [or] any high voltage system" the only rule he's breaking is A3.6,

" Violations on intent:
The violation of intent of a rule will be considered a violation of the rule itself."

...another black eye for the rules committee...

...hopefully they're listening...

...but I doubt it...

[Bemo]

I'd say usually teams usually only build accumulators from such materials for electric and hybrid cars. And in this case it is pretty clear that the accumulator is part of a high voltage system.

If you are talking about a low voltage accumulator, the driver doesn't need to be protected. Plus, the rules are pretty clear on what is considered high and low voltage. All in all I'd say the rules are pretty clear in this case.

[jd74914]

Originally posted by Canuck Racing:
I agree with you Brett, but from a rules standpoint if the accumulator isn't part of "the fuel supply, the engine oil, the liquid cooling systems [or] any high voltage system" the only rule he's breaking is A3.6,

" Violations on intent:
The violation of intent of a rule will be considered a violation of the rule itself."

...another black eye for the rules committee...

...hopefully they're listening...

...but I doubt it...

You do realize that most racing series have an "intents" rule.

-----
Hyjack over.

[Canuck Racing]

Originally posted by jd74914:


You do realize that most racing series have an "intents" rule.


I think all major series have an intent rule, but it's not an excuse for poor rules writing.

And typically when there is a violation - unless it could hurt someone - 9 times out of ten it's allowed through tech and there will be a rules update before the next race. (E.g. the people who write the rules eat their hat and admit they overlooked something.)

[artur]

yes.
on our last years car the accumulator containers were mounted to the sides and were made of carbonfiber with a fireproof resin, but we still had to use a firewall between them and the driver.

also:
T4.5 Firewall
T4.5.1 A firewall must separate the driver compartment from all components of the fuel supply, the engine
oil, the liquid cooling systems and any high voltage system...

the hv wires also count as part of the high voltage system so you have to cover them too. that means even if you have a fireproof container, you probably have wires running out of it which you need to cover aswell.

[Bemo]

Originally posted by artur:
yes.
on our last years car the accumulator containers were mounted to the sides and were made of carbonfiber with a fireproof resin, but we still had to use a firewall between them and the driver.

Sorry I have to play the smart ass here, but there isn't such a thing as fireproof resin. What you mean is self-extinguishing resin. This only means that it won't feed a fire. This doesn't mean it gives any real protection from fire. In my opinion only something with a metal surface should be considered as firewall.
We had an incident with our 2010 electric car. One accumulator started to burn while driving. The driver could escape quite quickly without getting hurt. After the fire was extinguished it was clear that the only thing that gave a real protection was some aluminium sheet which was installed between the driver compartment and the accumulator. All composite parts around the accumulator and the containment of it were completely destroyed.
CFRP parts which are laminated with self-extinguishing resin don't really provide much protection.

In 2010 we used aluminium sheet with nomex on the driver side. I'm still convinced this is a very good solution for electric cars. It is very light weight and easy to make, while giving a huge benefit in terms of safety.