187 replies to this topic

[dattoman]

Hotrods don't have to use a bonnet

[Shiney005]

The reason you can't run a car without a bonnet, or with a reverse cowl scoop that isn't sealed around the carby with an open back (ala A9X) is if you lose coolant or oil from your motor it ends up on the windscreen. I turned up at Ravenswood Raceway (drags) back in the late 80s without a bonnet and was told it wouldn't pass scrutineering.

[8BALL]

Apparently if you hit a pedestrian they could get "caught up" in a fwd open scoop ??
And the reverse cowl tends to allow them roll off?

An open engine bay is illegal for the same reason as the fwd opening scoop.

Someone somewhere decided it would be safer etc.

Sane reason cowl mounted gauges and superchargers out the bonnet are illegal.

So thats why reverse cowl scoops are so popular. People want to driv on the street legally and without hassles so they fit them to satisfy the engineer signing the car off.

[Bigfella237]

"NCOP6_Section_LH_Body_and_Chassis" (page 12) says:

 

For vehicles manufactured prior to 1 July 1988, there are no specific design rule requirements
relating to bonnet scoops. However any such fixture that is a dangerous protrusion or obstructs the

driver’s forward view of the road, is prohibited by both the ADRs and AVSR.

 

For vehicles manufactured on or after 1 July 1988, ADR 42/... prohibits external or internal protrusions

that are not technically essential and are likely to increase the risk of bodily injury to any person.

Rigid engine-mounted components that are likely to increase injuries to a pedestrian in a collision must

not project through and above the vehicle’s original bonnet profile, unless protected with a cover

mounted to the bonnet.

 

Although some "Hornet" style scoops are perfectly legal.

 

The official test (from NCOP6):

 

 

It also goes on to say that:

 

Holes may be cut in the bonnet to allow the protrusion of an air cleaner or carburettor
above the bonnet line providing the protrusions remain underneath the bonnet scoop.

In these circumstances, the bonnet scoop or raised bonnet section must be
manufactured from mild steel of equivalent gauge to that of the original bonnet;

 

So most of these fibreglass/composite scoops would still fail anyway.

[8BALL]

Well i know any hornet scoop seen on the road here will be picked on by cops. Yet the reverse cowl seems ok.

Mates car has steel bonnet and fiberglass scoop and passed all tests and is 100% legal.

[gtrboyy]

Hate the look of reverse cowl scoops even silly brock scoop on my tubbed sle BUT it's probably why it doesn't get pulled over otherwise I'd have offensive 9x5 aircleaner clear out the bonnet.

[StephenSLR]

In these circumstances, the bonnet scoop or raised bonnet section must be
manufactured from mild steel of equivalent gauge to that of the original bonnet;

 

So most of these fibreglass/composite scoops would still fail anyway.

 

What if the bonnet is made of fibreglass? I believe this is the case with most of the ribbed scoops, you replace the bonnet rather than tack on a scoop.

 

s

[Shiney005]

How many fibreglass bonnets have been tested to ensure they don't have an impact on crumple zones and air bags and the like? My guess is that these would be illegal as well.

[StephenSLR]

How many fibreglass bonnets have been tested to ensure they don't have an impact on crumple zones and air bags and the like? My guess is that these would be illegal as well.

 

How many of the cars with them have airbags? lol

 

I get what you're saying and the engineer would approve it to the same regs as the year of manufacture.

 

One absurdity, you don't need rear seatbelts in some cars from the 60's but they won't pass you if you have US seatbelts in the rear, they'll tell you to remove them and then pass you with no belts.

 

s