What's better a 4-1 header or 4-2-1?

[UberDave]

I would assume 4-1 since I gives more individual push and not being crammed, but I don't really know.

Enlighten me?

 

[Rent]

Don't molest the Escort

 

[UberDave]

Originally posted by: Rent
Don't molest the Escort

I'm not

I don't have the cash. I'm just trying to learn, that's all.


edit: btw- Tricking out the escort would be a foolish thing anyway.

 

[Quixfire]

It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

 

[UberDave]

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Alright, thank you sir.

 

[WinkOsmosis]

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Why?

 

[UberDave]

Originally posted by: WinkOsmosis

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Why?

 

[Iron Woode]

Originally posted by: WinkOsmosis

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Why?

It has to do with tube tuning ie: length and diameter. This also affects backpressure and reversion and undercarriage clearance.

Stepped headers are just not designed for high rpm use.

 

[Quixfire]

Originally posted by: WinkOsmosis

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Why?

The design of headers is to improve the flow of the exhaust gases from the combustion camber to an outlet. Most headers are design to fit the compartment in which the engine is currently installed.

A typical 4-1 header are design to handle short exhaust pluses, such as the type that are developed at higher rpms, to scavenge the exhaust gases out and pull some of the new fuel mixture in.

Your 4-2-1 headers are design to handle long exhaust pulses, developed at lower rpms, to help maintain a certain amount of backpressure in the exhaust port to minimize exhaust scavenging and improve fuel efficiencies.

There is also a difference between a tuned header and a space saver. A turned header is designed to have one exhaust pulse follow another improving the flow of exhaust gases thought the header and even possible the exhaust system. A non-tuned header is designed to just fit the environment it needs to work in and most likely will not provide much improvement over the stock exhaust system.

 

[Howard]

Originally posted by: Quixfire

Originally posted by: WinkOsmosis

Originally posted by: Quixfire
It depends on you end goal. 4-1 header is better at high rpms, and horsepower development. 4-2-1 header is better for low rpms and torque development.

Why?

The design of headers is to improve the flow of the exhaust gases from the combustion camber to an outlet. Most headers are design to fit the compartment in which the engine is currently installed.

A typical 4-1 header are design to handle short exhaust pluses, such as the type that are developed at higher rpms, to scavenge the exhaust gases out and pull some of the new fuel mixture in.

Your 4-2-1 headers are design to handle long exhaust pulses, developed at lower rpms, to help maintain a certain amount of backpressure in the exhaust port to minimize exhaust scavenging and improve fuel efficiencies.

There is also a difference between a tuned header and a space saver. A turned header is designed to have one exhaust pulse follow another improving the flow of exhaust gases thought the header and even possible the exhausted system. A non-tuned header is designed to just fit the environment it needs to work in and most likely will not provide much improvement over the stock exhaust system.

Isn't 4-1 more efficient at higher RPMs because the pulse tuning isn't effective and you just need to minimize exhaust restriction?

BTW, I don't think you need to use 4-2-1 headers to make use of EGR - which is what you're referring to, aren't you?

 

[Quixfire]

Originally posted by: Howard
Isn't 4-1 more efficient at higher RPMs because the pulse tuning isn't effective and you just need to minimize exhaust restriction?

Yes, I stated that, but tuning is even more important at this level.

BTW, I don't think you need to use 4-2-1 headers to make use of EGR - which is what you're referring to, aren't you?

No, Exhaust Gas Recirculation has very little to do with a header. What I was referring to was the removal of exhaust gases from the combustion chamber due to improved exhaust flow.