No, you can’t legally put a blower on a Holden SS without engineering certification because of the >20% power increase. It is eligible because of HSV but still needs compliance because it is not how Vehicle was prepared from factory.
Indeed. Just because HSV's came with blowers doesn't mean installing a blower automatically makes your car an HSV; because you're not running the same tune, not running the same brakes, etc.
It's one of those grey areas that's actually black-and-white.
The black-and-white bit is the fact that it's definitely not legal.
The grey bit is whether you'd be affected by the illegality; your insurer is within their rights to refuse to cover you, but they may still do so. The cop may be looking for anything to nail you with & a canary for an unapproved modification is a nice easy one; but there may
be no cop.
Personally, I wouldn't be game, and I'd get the certification.
Note also that some complete kits are engineer certified. I don't know the current offerings, so don't know that any of them are or aren't.
But I do remember for example that when someone bought the rights to the HDT brand-name (late 90's?), they were doing mods that they were getting engineer-approved. I'm pretty sure CSV were doing that too. Although I guess both those mobs were selling complete cars.
However - my point with this comment is that NSW RMS requires you to carry the certificate in the car; so if you've got a kit that's been certified, then it should be possible to get a certificate for your car.
Interesting thing is that no matter what output gets certified the noise must be same as left the factory.
I wasn't aware of that!
So if the rule for your year of car says "85dB at blah blah blah", yet Holden's official documentation says it did "83dB at blah blah blah", to the letter of the law you can no longer have your car generating 85dB at blah blah blah?
[My car's engineered under pre-NCOP rules, most things are the same as they were in NSW 20 years ago but there are still differences like this - my car only had to meet 1979 rules, regardless of whatever Volvo type-certified it with]