I've been sitting here trying to work out what set of extractors would be the best to modify to suit my 3" exhaust that I'm slowly building.
I thought I'd post the results up so that if anyone else is interested/in a similiair situation, they've got some grounding to start looking.

So I've been looking at the difference between the brands in sizes of there primaries and secondaries. The outlet flange is not overly important as I will be cutting this and making it 3".

Basically the Genies have the equal largest diameter primary and secondary pipes. There primaries are 41.275mm and 50.8mm for the secondary. But, These are Tri-Y extractors, so the total area for the secondaries is 6,080.49mm2 (3*(pie r squared)) - r = 25.4mm).
The other extractors with the same size primaries and secondaries, are 6 - 2 -1, so you only have 2x 51.8mm secondaries, as opposed to the Genies which has 3x 51.8mm secondaries.
Obviously the Wildcats are equal to the Genies, but Wildcats are press-bent, so that's a restriction compared to the mandrell bent Genies.
I'm not sure what the difference is yet between the Genie 694E and 692E, both are Tri-Y with the same size primaries and secondaries.

The only extractors I havn't been able to compare are HM Headers, but these are 6 - 2 - 1, so in order for the secondaries pipes to have the same area as the Tri-Y Genies, they'd have to be 62.22mm's, which I highly doubt they'd be when they have a conservitive outlet flange size of only 2 1/4".

Pacemaker 4499's tri-y headers?

Yeah, both types of Pacemakers are Tri-Y design according to http://www.pacemaker.com.au/ford_falcon_6cyl_ea-au.html

i dunno what the f**k tri-y means (im guessing 6-2-1)...but 4480 are 6-3-1 and 4499 are 6-2-1. I have 4480 and they're alright...i think they're meant to be better particularly up high (which im guessing is important seeing as you are using a 3in exhaust), cause they are 'apparently' a tuned length design...

those genies seem to have a bigger cross section on secondaries so may be better. In saying this I'm assuming your using a blower cause of the 3in exhaust? If not i would go the 4480's cause exhaust velocity will be higher which means they're hotter and therefore lighter and require less force to push out

Yes, 3" exhaust system because of the blower.
I think Tri-Y means 6 - 3 - 1, according to the Pacey catalogue all there pipes should be Tri-Y, but perhaps they've made a mistake. Either way the Genies have larger diameter pipes.

Last edited by twr7cx on Mon Apr 07, 2008 8:16 pm, edited 1 time in total.

yeah probably better to go with the genies cause of the bigger diameters then.

there's other factors like bend angles and length of primaries/secondaries but as long as they're mandrel bent im pretty sure there will be sfa difference due to this

Tri-Y means the primaries go into separate collectors, but on this basis:

The principle behind tri-Y design is that the most effective port separation occurs by pairing the cylinders that are firing f@rt apart, in other words 180 distributor degrees (or a complete crankshaft revolution) apart

My brother has a set of Genies on his EBII and i have a set of 4480's on my EL, and mine seems to have a heap more power all the way through the rev range. I'm pretty sure the AU Saloon cars use the 4480's with a 3" modified flange with a 3" exhaust aswell

Fair few other factors in there. I.e. EB is older, EL has the BBM which should improve low down torque, etc.

oh yep forgot about BBM, his engine has only done 20k though

yes correct, Au saloon car have the headers cut with a 3 inch pipe(exhaust) welded in!!!

yes correct, Au saloon car have the headers cut with a 3 inch pipe(exhaust) welded in!!! yes they use 4480's

forget 4499's they are nice for torque but if you want a worthwhile increase 4480 and modified 3" flange thats what i have into a 3" system 1 muffler.

Anyways, turns out that the Pacey Comps are going to be the way to go (or continue), the Genies are only 6 - 2 - 1, therefore the seconaries on the Pacey comps are better as there are 3 of them (they have greater total area).
So I'll be copying the saloon cars.
Spewing that Pacey don't offer theres in Stainless Steel as that'll be the only part of my exhaust not stainless.
Anyone got any pictures of the modified flange on a set of Paceys on the saloon cars?

Got a picture of the modified flange on the headers?