Tuned length extractors

[drift kid]

All good, I just wana clear up the speculation between 4-1 and 4-2-1 styles

[drift kid]

I wana make these but they look scary lol

[SamsTA22]

Anyone who has dyno sheet comparisons would be helpful.

I would be curious to see how a set of longer 4-1 headers would compare to 4-2-1 in terms of power delivery.

If I was going to spend the money on good headers, I cant find a properly good set online for under $1000. Yet a decent exhaust shop basically quoted $200 a cylinder a while back. I know which route I would take.

[KurtHS]

$200 a cylinder?! That's cheap!

[drift kid]

By stepped you mean like 1.5" primaries into 1.75" secondaries into 2.25" finals? Sorta thing?

[Frak]

Ben, say having a set of 4-2-1's and the primary pipe is different in diams, so the step may be in the primary pipe only.

Pat totally agree, it's so interesting, cos sometimes something which theorectically should work, doesn't and some piece of crap, works good. I find nowadays getting gains over factory stuff can be hard, or where you gain somewhere you lose somewhere else, even though the manufacturers have to package, they still do quite a bit of work.

I've been quite slack lately but have collected quite a large number of 4age headers(4-2-1, 4-1, long primaries, short primaries etc etc) and have been meaning to do a back to back and see how they all perform on the same engine.

[fantapants]

sam i think the confusion over those merge sets stems from the builders copying half a v8 manifold. and being cheap.

fwiw design and precision are more important than arbitrary 4-2-1 or 4 -1 setups. This is only my opinion, but making sure you get the numbers right will have a greater bearing on how the exhaust perfoms than making it fit with pretty junctions.

Dont skimp on merges. These are the make or break of a proper manifold. Get them wrong and the whole lot is just a shiny piece of shit.

[drift kid]

Yeah, it makes sense, I have thought about making my own, that way the quality is in my hands, I've looked at buying a pipe stretcher to do the slip joints but still not sure what direction to go

[Sam-Q]

I just remembered something, quite a few years ago there was someone on here who did a heap of back to back runs and they said a 20v was the most sensative engine out of any they had ever tested in regard to collector design. Small changes had big differences in torque.

Here is my home made effort from many years ago:

[Sam-Q]

if oyu want something really nice try this place:



probably costs a fortune though