Do you need backpressure?

[Alley]

Say you were running open headers. You have no backpressure. Is that going to give you the best HP #'s? Or do you need some backpressure for optimum horsepower?

Care to comment Thunder? :bolt:

[Kelvin]

depends on the application. noob

[JesterMX6]

open exhaust will usually net u more HP up top but less torque down low IIRC.

its been a while since i've looked into this so i could be really off.

[Thunder]

Say you were running open headers. You have no backpressure. Is that going to give you the best HP #'s? Or do you need some backpressure for optimum horsepower?

Care to comment Thunder? :bolt:

The exhaust system should have minimal restriction to the exhaust flow that is being released in order to create the most amount of power from the engine. With restriction present, backpressure is developed, making the engine work much harder to release the exhaust out of the engine cylinders.

The standard for exhaust diameter is to not run too large of exhaust, for the engine needs a certain amount of backpressure. This is correct in the sense of one should not run too large of diameter exhaust tubing, but the statement of the engine needing backpressure is not. You need to have the least amount of backpressure possible to produce maximum power. Too large of diameter exhaust will cause a power loss and loss of low end torque because a larger pipe has less exhaust stream velocity than a smaller pipe. If the exhaust pipe is too large, then the exhaust flow will be slowed with less velocity. There are exceptions, forced induction or high-volume race engines require a larger diameter exhaust due to the flow characteristics of the engine. Supercharged and turbocharged vehicles can have an exhaust gas volume of 1 to 2 times more than an equivalent displacement naturally aspirated engine. In this case, one is able to use a larger diameter of exhaust for greater performance.

[srt-4_uk]

get a turbo. then you can have backpressure and run open exhaust. That is what the cool kids do.

[JesterMX6]

there's no such thing as back pressure.

[86Shelby]

there's no such thing as back pressure.

Wanna bet?

[JesterMX6]

sorry.

/yellow

[Kelvin]

I just realized what this thread is really meant for.

[Thunder]

I just realized what this thread is really meant for.

:lol:

[turbodaytona87]

any backpressure is bad, but unfortunately back pressure helps with scavenging. That's why you have less torque with open heads than with a full exhaust because it can't scavenge correctly.

[BOORAH]

I just released all my backpressure.

**** reeks.

[Yngvar]

^:rofl:

[Alley]

Well, then lets scratch stricly HP #'s then. What about track times. Will having some backpressure ie more torque, net you a better ET then just having open headers and as much HP as possible?

[BOORAH]

I think that could go either way.
But idk ****.

[Kelvin]

go to the shop and do some mythbusters **** alley. have thunder strap up and see what it puts down for hp and 1/4 times. its a controlled enviroment theres no way he could miss 3rd

[Thunder]

go to the shop and do some mythbusters **** alley. have thunder strap up and see what it puts down for hp and 1/4 times. its a controlled enviroment theres no way he could miss 3rd

:joe:

[Kelvin]

lol sorry

[BOORAH]

Yeah don't doubt him.
He could miss it somehow.

[schovil69]

Well, then lets scratch stricly HP #'s then. What about track times. Will having some backpressure ie more torque, net you a better ET then just having open headers and as much HP as possible?

Track test time! run one: mufflers, run two: open headers

[Slikrider]

Thinking about running open headers on the V10? That would be sweet

[Thunder]

^ LOL

[turbodaytona87]

its a controlled enviroment theres no way he could miss 3rd

:lol:

[Cobra Commander]

What about track times. Will having some backpressure ie more torque, net you a better ET then just having open headers

My black GT got WAY slower after running open exhaust. It was weird. ****er had it's low-end back again once I threw a catback on it.

[Hillbilly]

If u have a vehicle made to have exhaust the cam will be a split pattern and tend to over scavange the cylinder. With the proper cam it would make more power.

[MadmaX]

^yes.

you don't need backpressure, you need airflow. if it takes a smaller exhaust to give you good airflow, the extra backpressure it has is just a tolerable side effect.