[the_orb]

is there any difference between 4 to 1 and 4 to 2 extractors, apart from $60?

[royce]

4>2>1 give a lower power gain, but over a wider range
4>1 give a higher power gain but in a narrower (higher) rev band

unless you are sitting in a narrow band all day long (say like a race car or on the highway all day) I would go 4>2>1

[GRPABT1]

Like mentioned above 4-1 make power high up, which would suit the small revvy zook motors. BUT in a 4B you want all the low down torque you can get so stick with 4-2-1's, you'll still get decent power gains over stock.

[the_orb]

4 to 1 sounds the go, i need it for highway speed

the drover im taking it off does not have a cat, is that legal? if so it will make installation easier coz there will only be one weld

[cj_zuki]

As a generalisation the 4 to 1 tends to be designed for a specific rev range but will deliver more power in that range where as the Tri-Y will deliver a lower power level but spread over a larger range. This does not mean that the 4 to 1 is a high rpm range design but it is more commonly found in that application as it is ideal for things like circuit racing. The thing is that a header should be designed around a specific set of engine criteria and a poorly designed 4 to 2 to 1 will not be as good as well designed 4 to 1. If you change anything on your engine you then need to redesign the header but in reality 99% of people will just buy what is available off the shelf and settle for whatever that delivers.

[the_orb]

cj_zuki wrote:

As a generalisation the 4 to 1 tends to be designed for a specific rev range but will deliver more power in that range where as the Tri-Y will deliver a lower power level but spread over a larger range. This does not mean that the 4 to 1 is a high rpm range design but it is more commonly found in that application as it is ideal for things like circuit racing. The thing is that a header should be designed around a specific set of engine criteria and a poorly designed 4 to 2 to 1 will not be as good as well designed 4 to 1. If you change anything on your engine you then need to redesign the header but in reality 99% of people will just buy what is available off the shelf and settle for whatever that delivers.

yeah thats me i just want to be able to sit on 100 on our upcoming road trip.

any thoughts on the cat?

[cj_zuki]

Cats generally don't provide that much of a restriction. If you want, go up one size compared to the pipe you are running and you will be fine.

[joshNZ]

just get any you wont be able to tell the difference when u get them.

[the_orb]

shod be getting them Friday after work. installing as soon as i can find a welder

[steve]

joshNZ wrote:

just get any you wont be able to tell the difference when u get them.

i think this'd be about right. ..and i reckon you'd find it hard to actually pick the difference between extractors and none at all.

I've never been a beleiver in extractors, since i got some for the hilux and the dude said they'd be the best thing i'd ever do, and i drove up the road, and it made no difference at all, and sounded like an old torana

[royce]

yeah but thats a diesel

my 4>1 were probably the reason my 1.3 used to beat your 1.6 on the highway

[steve]

nah, that was coz your cars are just better than mine. I always get the special edition slow version of everything. Bear's hilux, exactly the same motor use to beat mine easy.

[royce]

stick some windex..oops I mean diesel power in that will fix it

bugger, tech posts about a hilux, I better go ban myself now

[joshNZ]

there'd be no way extractors made a 1.3 beat a 1.6,i had a 1.3 with extractors and mine bet a 1.6 with extractors,if u put a turbo on then youll feel a difference

[royce]

well it did used to pull pretty hard at 4000rpm, but what would I know

[joshNZ]

i wouldnt no either