[Neil.Bhujbal]

A week ago i was going through someones modded baleno/vtec thread.
That guy was looking for various cam profiles or something,

To which Psycho had said " Since you already have tuned headers on your car your tuner must be knowing the cam profile "

I had saved link of that post but i am not getting it now.

Can anyone tell me how is the cam profile & header design relate ?

Any link or any of you could explain it to me in a less complicated manner ?

[CPH]

Originally Posted by Neil.Bhujbal

A week ago i was going through someones modded baleno/vtec thread.
That guy was looking for various cam profiles or something,

To which Psycho had said " Since you already have tuned headers on your car your tuner must be knowing the cam profile "

I had saved link of that post but i am not getting it now.

Can anyone tell me how is the cam profile & header design relate ?

Any link or any of you could explain it to me in a less complicated manner ?

In simple terms you need tot know some parameters of the air intake and the closing angles to design the whole exhaust.

The exhaust manifold on a inline 4 is fairly easy to calculate unless you have siamese ports to deal with.

Also the calculation of a 4 in one is different than a 4 in 2 in 1 design.

Depending on what you want to achieve you can step the header as well as make it uneven pipes in order to increase/stretch the torque delivery.

However whatev er you do you have to decide first whether you want to go for peak power or wide spread torque and where the desired peak power point is. From there you calculate the exhaust manifold.

[pranavt]

I wouldn't call it a "relation". The whole engine is a system made up of various sub-systems. If you have a high-lift medium-duration and overlap cam and mix it with headers made for low-mid range torque, the advantages of both will be lost to an extent. What he probably meant was that if the tuner knew his header configuration (primary, secondary lengths, diameters, collector configuration), then the cam would have been chosen keeping in mind the same powerband.

Just an assumption though, and since Psycho's active on these forums, best to hear from him.

[Neil.Bhujbal]

Hey thanks for the explanation guys.

Here's what i have got after going through your replies & some net info.
(do let me know whether i am getting it right)

1) You should know the air intake & cam profile for designing the headers.

2) Camshaft can be designed to overcome the loss caused due to restrictive intake or exhaust system.(the non symmetrical camshafts)

So if a custom cam is designed which allows more air-fuel into the cylinder & exhaust gases to exist faster the headers will be re-designed accordingly.

but ..

Re-designed means the length of pipes will be increased slightly or the diameter of pipes ? Or both ? to accommodate the extra exhaust & let it out quickly ?

If yes, is there any equation using which the length & diameter increase of the header is calculated ? Or is it just a blind guess i.e slight increase in diameter & length over stock size ?

[Psycho]

This is one of the best explanations I have come across for this topic.

Signal to Noise Exhaust Design - Marcus Fitzhugh

[Neil.Bhujbal]

Originally Posted by Psycho

This is one of the best explanations I have come across for this topic.

Signal to Noise Exhaust Design - Marcus Fitzhugh

Spot on.Thanks Psycho.