Make Your Own Extractors And Exhaust

[smurfpirate]

hey im probs going to try make my own headers and exhaust my plan is to use the flange of the old headers for the new ones ill weld up and go of the old ones for measurments and what not. i want to use my old cat for the time being and just buy a muffler has anybody tryed doing this and how'd it go??.

[NA_R33]

Hey mate, ive made a few different sets of headers... if ur handy with a welder and fabrication its not a huge task. But to be honest i only do it when off the shelf stuff isnt a available or a is overly expensive, by the time u buy bends and pipe it ususally doesnt work out much cheaper even getting them at trade prices.

[NA_R33]

Just too add, there is plenty of info floating around the net on header design, do a bit of research to find out what ur after, eg. length of primary and secondary pipes and collector arrangments.

[mad082]

yeah i agree with both of the above posts. by the time you buy the bends, collectors and piping and spend the time doing it it might be much cheaper and easier to just buy some.

and design can make a big difference. if you get 1 pipe slightly out of place you may have it that it doesn't line up with the rest of the system., and then you end up with an exhaust that hits the body every time you go round a corner. also length of primaries and secondaries can affect torque, etc.

also make sure you get your welds right on your collectors otherwise they will leak.

[Fixxxer]

As well as the length of primary pipes, the size (I.D) of pipe will offer benefits at a different RPM ranges. Helmholz (sp) resonance from what I remember. There is a lot of info out there on correct size/length and design of headers, have a look if your interested in getting the most out of it.

In real terms, the change from a poorly designed cast iron log type header to just an off the shelf primary/secondary header will offer good benefits.

Fixxxer

[smurfpirate]

well i can get a bender so i was just going to bend the metal myself but yea ill do alot of more research first. is there anyplaces that stcok them cheap tho??.

[SKiT_R31]

well i can get a bender so i was just going to bend the metal myself but yea ill do alot of more research first. is there anyplaces that stcok them cheap tho??.

does anyone have a link to this info about length, diameter etc, and effects, as I'm curious

cheers

[mad082]

smaller diameter will give more low down power as the air will syphon itself out better, but you lose top end due to restriction. a bigger pipe will flow better up top but it loses the scavenging effect at low rpm.

if you are bending the pipe yourself without a bender you could end up with a real mess. if you insist on doing it yourself buy some mandrel bends. they will cost you a bit but will come out much nicer.

[NA_R33]

does anyone have a link to this info about length, diameter etc, and effects, as I'm curious

cheers

Google is ur friend, search header design there is a rediculous amount of material available.

[tridentt150v]

And every weld is a possible stress point. All stress points will fatigue in time=cracks. A good single length mandrel bend pipe eliminates this [except at the flanges and other obvious locations].