US Headers & Exhausts NA

[Dupain]

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Because it was longer than the others.

[project.r.racing]

Do you even understand what tuned means?

Gas flow rates to the collector from each outlet. Arrive same time.

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Because it was longer than the others.

Then gas flow rates will be different.

[Dupain]

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Extractor manifolds
Most non-turbo performance cars and high-performance four-stroke motorcycles use extractor manifolds, as do most non-turbo racing cars. Extractor manifolds are also available as aftermarket accessories to suit many engines.

Extractor manifolds offer the following advantages over the simple manifolds often fitted to non-performance engines:

Separating the gas flows from the individual cylinders so that undesirable inter-cylinder interference is avoided.

Maintaining an optimum gas velocity by carefully chosen tube diameter.


Allowing the individual cylinders to assist one another by means of the negative pressure waves generated at the collector, where the individual exhausts merge.[3]
This type of exhaust system can be used with or without a muffler, and so can be used on both race and road vehicles.

[project.r.racing]

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Extractor manifolds
Most non-turbo performance cars and high-performance four-stroke motorcycles use extractor manifolds, as do most non-turbo racing cars. Extractor manifolds are also available as aftermarket accessories to suit many engines.

Extractor manifolds offer the following advantages over the simple manifolds often fitted to non-performance engines:

Separating the gas flows from the individual cylinders so that undesirable inter-cylinder interference is avoided.

Maintaining an optimum gas velocity by carefully chosen tube diameter.


Allowing the individual cylinders to assist one another by means of the negative pressure waves generated at the collector, where the individual exhausts merge.[3]
This type of exhaust system can be used with or without a muffler, and so can be used on both race and road vehicles.

nice wiki copy and paste.

but changing the diameter of a single pipe alone will screw up theories you just copied and pasted.

[Dupain]

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Extractor manifolds
Most non-turbo performance cars and high-performance four-stroke motorcycles use extractor manifolds, as do most non-turbo racing cars. Extractor manifolds are also available as aftermarket accessories to suit many engines.

Extractor manifolds offer the following advantages over the simple manifolds often fitted to non-performance engines:

Separating the gas flows from the individual cylinders so that undesirable inter-cylinder interference is avoided.

Maintaining an optimum gas velocity by carefully chosen tube diameter.


Allowing the individual cylinders to assist one another by means of the negative pressure waves generated at the collector, where the individual exhausts merge.[3]
This type of exhaust system can be used with or without a muffler, and so can be used on both race and road vehicles.

nice wiki copy and paste.

but changing the diameter of a single pipe alone will screw up theories you just copied and pasted.

If you can't undestand from wiki, I can't help you.

[emily_mx5]

This is so hilarious.
Please continue.

[sailaholic]

The problem is you can't understand. My question is not because I didn't understand extractors. It was asking you to think about your reason for making one tube smaller.

A given volume of air will have an optimum size primary. You then lengthen of shorten primary's to match each other and desired rev range.

Making one tube smaller means non optimum gas flow in that one. This means more restriction so more gas left in the cylinder when the intake charge starts trying to get in.

[greenltd]

Dupain is great. On at least two threads showing us his level of intelligence. ...... should learn to shut up.

[Dupain]

The problem is you can't understand. My question is not because I didn't understand extractors. It was asking you to think about your reason for making one tube smaller.

A given volume of air will have an optimum size primary. You then lengthen of shorten primary's to match each other and desired rev range.

Making one tube smaller means non optimum gas flow in that one. This means more restriction so more gas left in the cylinder when the intake charge starts trying to get in.

I'll try and make it simple. Think an engine as much like a pump. The main variables are length and internal diameter. The gases have to get from the primaries to the collector at the same time.

[Dupain]

This is so hilarious.
Please continue.

Maybe words from a shelia can sort out the queries. I've tried my best to explain.

[Dupain]

If each cyclinder creates the same volume of gas why would you make one primary smaller?

Length. It's longer.

[sailaholic]

*facepalm* you can lead a horse to water...

[project.r.racing]

All I can say from this point on is - get an education.

[Dupain]

All I can say from this point on is - get an education.

Can't help you if you can't understand.

[hks_kansei]

Dupain, you should also ask if they can do a custom set for you in aluminium.

Because it's a lot lighter than steel you would get the performance gain from the tuned diameters, and a good weight reduction.


Even better would be magnesium, but that's getting expensive.