4 - 2 - 1 exhaust manifold.

[superls]

Hi everyone,

im getting a fabricator friend of mine to make me a 4 into 2 into 1 manifold for the k10. what we need to know is, does it matter which cylinder ports are connected together,

ie. 1-2, 3-4
or 1-3, 2-4
or 1-4, 2-3

?????

is there any differencein the configurations?

its going to be made mild steel a minimum of 1.5 inch od.
its going to join the 4 into 2 as it drops down the front of the engine and 2 into 1 as it goes under the engine.

any feedback will be greatly appreciated

superls

p.s. depending on the success and interest ive talked him into possibly producing a few of them...

 

[curtis]

will it improve bhp?? if so then count me in!!

 

[superls]

i would have said so taking into consideration how restrictive the standard manifold is....

i havent spoken prices with him yet, but when i no ill let you know, but im having one anyway, so when its done ill take photos and whatnot.

 

[curtis]

good good, well there should be some sort of increase!

 

[whipit]

You really want the 1-4 to connect and the 2-3 to connect, it does matter andits does make a difference, its all to do with the time difference when a cylinder is on its exhaust stroke.

will it improve bhp?? if so then count me in!!

Your only talking about a few bhp increase but its will come in lower down and your torque will be higher up the power band.....basicly.

 

[superls]

You really want the 1-4 to connect and the 2-3 to connect,

Really, as ive read somewere that you need 1-3 2-4?

But to be sure i asked the question and it looks like i was wrong (again)lol

a few bhp increase but its will come in lower down and your torque will be higher up the power band.....basicly.

Perfect!!!

 

[ollyc98]

I thought 1-3 and 2-4 would be bad as that would be a high volume of gasses down the same pipe as if I remember rightly 1 and 3 and 2 and 4 fire together.
Also I think the length of pipe is important as the restriction has to be the same.

You could modify a Mk3 fiesta manifold if you want to be cheap as they are 4-2-1 as standard.

 

[sonic]

only one plug ignites the mixture at a time, 1-4 and 2-3 reach the top of the stroke at the same time but at different stages of the cycle.

 

[whipit]

Currently working on fitting a k11 janspeed manifold with out changing the flange, ill put up pics and info when its done.

 

[ollyc98]

only one plug ignites the mixture at a time, 1-4 and 2-3 reach the top of the stroke at the same time but at different stages of the cycle.

Oh right, I'm still learning about the strokes and that.

 

[bobsp16]

Oh right, I'm still learning about the strokes and that.

lol sounds like it


..no for the road you wont a 4 into 2 into 1 thats 1-4 and 2-3 together like this one

 

[superls]

Thats A Nice Manifold, Where Is That From And How Much Was It.

1-4, 2-3 It Is Then

 

[bobsp16]

i am not useing it at the moment.i am trying a 4 into 1 manifold i made out of a motorbike exhaust downpipes

 

[whipit]

Your have to stick it on the rolling road for us mate!

 

[bobsp16]

Your have to stick it on the rolling road for us mate!

ive lost a bit of mid range but its better up the top

 

[Craig]

Where do you get your flanges made up bob, also, is that lower picture 4-1?
Craig

 

[whipit]

Where do you get your flanges made up bob, also, is that lower picture 4-1?
Craig

yeah thats the new one hes working on

 

[bobsp16]

Where do you get your flanges made up bob, also, is that lower picture 4-1?
Craig

if you notice ive cut off the flanges from the 4-2-1 and yes the lower picture is a 4-1 which ive used the flanges on

 

[superls]

is the flangless manifold 4 sale?

 

[daveeeeee]

will it improve bhp?? if so then count me in!!

yes it will increase bhp, but you'll get far more gains opening up the inlets. bob has a custom inlet system on ebay (i believe) for about the same price as a full exhast manifold and system would cost you, but you'll get about 20-25 bhp opening up the inlets. where as the exhast system will only give a gain of around 10bhp, not even that.

correct me if i'm wrong.

 

[whipit]

yes it will increase bhp, but you'll get far more gains opening up the inlets. bob has a custom inlet system on ebay (i believe) for about the same price as a full exhast manifold and system would cost you, but you'll get about 20-25 bhp opening up the inlets. where as the exhast system will only give a gain of around 10bhp, not even that.

correct me if i'm wrong.

your about right, its how and where it directs the power to in the power band that makes the real difference.

 

[bobsp16]

I wouldn't of throught you would even see a gain of 5bhp by only changing the exhaust manifold and system......
Change the inlet 1st if you dont want to then bin the standard carb for a little weber even that on a standard manifold make prob 10 more bhp

 

[SammoHung]

There's some more discussions on sequential and non sequential manifolds in my blog...the manifolds chatter starts at post #22

http://www.micra.org.uk/showthread.php?t=15891

(Notice mine is the opposite type to bobs)

there are some diagrams that might help to explain the differences.

theres also some stuff elsewhere on the web too if you dig a little

have fun

 

[RTLkyuubi54]

bulk buy if we get enough people?

 

[superls]

bulk buy if we get enough people?

maybe?

 

[whipit]

Is there anything to bulk buy? lol