Corvette6317 wrote:1976 saw a 10% drop in power for the Holden 308, was that because of the EGR?
Nope, it was from the reduced engine tune required to meet ADR 27A
http://www.gmh-torana.com.au/forums/topic/29519-torviki-lx-pollution-gear-adr27-amp;-a-explained/This was taken from a Torana Owners forum and there is no mention of catalytic convertors at all...
It is possible that you have seen a pre 1986 Holden with a catalytic convertor as modifying an older car with an engine that has to comply with a newer, more stringent, ADR requires the emissions controls to be installed as well. Another modification that can be mistaken for catalytic convertors is the installation of a "hotdog" muffler in the exhaust. These "hotdog" mufflers are a wider section of pipe installed in the exhaust (coincidentally where a cat sometimes resides) which deepens the exhaust note.
Automation doesn't need to include cats for Leaded cars because Leaded fuel is incompatible with catalytic convertors. I cannot find
ANY evidence that any manufacturer used Leaded fuel with catalytic convertors anywhere in the world. I'm not saying that it isn't 100% possible that someone tried it but, since you cannot provide evidence of Holden using them Corvette6317, I strongly disbelieve that Holden, who was owned by GM in 1976, was the one who bucked the world trend.
If you can prove your claim Corvette6317 then I'll be the first to admit I'm wrong but until then, please take the time to read the provided links and do some research of your own!
BTW, I used to be a parts interpreter and I was burnt by making assumptions... I had a customer come in with an AMG tuned Mitsubishi Galant! I didn't believe him so when I saw the car I was forced to eat some major humble pie... I looked on the Internet and confirmed the customers story. AMG (of Mercedes Benz fame)
had built and tuned a number of Galants for the Japanese market!
