stepped headers 4 into 1 design

[Celica RA45]

has any 1 played around with stepped headers at all .by this i mean 1st 8inches 1.3/4 then up to 1.7/8 etc

[ed]

not in real life, but i did the maths, and its a complete headfuck

from best i can tell, short of the first step off the manifold flange, the rest becomes a packaging gain rather than performance gain. ie you can achieve tuned length in shorter space, and less weight. re: f1 stumpy Ti exhaust

[oldeskewltoy]

has any 1 played around with stepped headers at all .by this i mean 1st 8inches 1.3/4 then up to 1.7/8 etc

What engine? What mods?

[gixer]

Not 4-1's but have messed with 4-2-1's
ST 4AGE



original on right, stepped on left

[amichie]

Red curve old header. Blue curve new header??

[gixer]

Red curve old header. Blue curve new header??

oh yeah, I should of wrote that, thanks, red old, blue new.

[NME308]

oh yeah, I should of wrote that, thanks, red old, blue new.

Hey gixer, what pipes are those which are compared in the dyno result i.e. pacemaker/hurricane/garden variety? I'd love to have seen results of a set of garden variety 4 into 1's just for comparison as well. I have used the old school math for 4 into 1 headers for V8's a couple of times with good results, but never tried stepped pipes. Were yours used just as pictured or did you test any different combo's of pipe size?

I know the stepped 4-2-1's when done right can be better all round pipes than 4 into 1's however last I knew the math was crazy and experiment seemed the best way of getting them right...

Cheers,
Jason

[WDE_BDY]

Look like the factory 20V headers, most aftermarket ones seem to go backwards in power so that is a good result for the stepped headers.

Callum

[mattysshop]

Very common practice over at Extreme Custom Engineering.. not just V8's either.. but these are the only pics i have at the moment...

[Celica RA45]

now they are proper stepped headers