Headers... Are they worth it?

[chaditotx]

I am having a hard time convincing myself shorty headers for the Yaris offer much from the threads here. My 2012 5dr 5 Spd SE is a little doggy compared to my stripped down 07. Looking for a little pep.

[tmontague]

Imo it was a worthy mod to do, aided in lowering the torque curve by about 500 rpm and seemed to help a bit in the higher rpm with extra torque/hp. The 1nz will still fall flat above 5500rpm but not much can be done about that with aftermarket bolt ons

[thebarber]

Good mid range hp boost. With intake and a full exhaust it helps the car pull all the way to redline

[Yaris709]

Did the gas mileage be affected with aftermarket headers?

[ern-diz]

Originally Posted by thebarber

Good mid range hp boost. With intake and a full exhaust it helps the car pull all the way to redline

Even without being able to tune?

[WeeYari]

Originally Posted by ern-diz

Even without being able to tune?

Yes. Front to back, air in/air out needs to be addressed in order to realize appreciable gains. Standalone, intake, header, exhaust modifications really don't do much. It really needs to be done as a package.

[thebarber]

Originally Posted by Yaris709

Did the gas mileage be affected with aftermarket headers?

the harder you drive, the more gas you'll use

Originally Posted by ern-diz

Even without being able to tune?

oh yes. it's noticeable.

[ern-diz]

Got it, good to know, thank you both.

[mr_robot]

I just don't see how aftermarket headers especially the Megan ones would gain anything compared to stock.

I took at look at the stock and it's actually a header not a manifold.

For headers to provide gains, it would need to increase velocity. People are so concerned about "flow" and restrictions when exhaust is not really affected by neither too much as it's pulses rather a flow.

So anyways, lol I decided not to get headers unless you go with a full length type that puts the collector further away and actually increase scavenging and velocity.

Lastly, I would still get the Megans and the likes if the header was visible from the engine bay, at least it would look pretty haha!

[tmontague]

^although I do agree with you with a lot of your points, push the 1nz up above 5k rpm and then do so with a DC sports header and you'll start to see the difference. The larger diameter of the DC header aids in the flow. at 5k+ rpm the pulses are a lot less of a pulse and more of a flow and this is where the restriction comes into play.

With an aftermarket header you may lose low end torque but if you rev it out a lot top end can be improved

[mr_robot]

DC headers are 4-1 and technically extends the collector 2-3" (never seen in person so don't know the exact measurements.) So that's probably where you will see some gains.

Losing low end torque with aftermarket headers has to do with primary size. If Megan and DC use larger primaries then you are slowing down the velocity as it exists out the exhaust port. And the gains are gained up top where as you say "flows" more gases can take advantage of the larger primaries.

If you want the best header possible it would be stepped (oe size at port, larger few inches back and a collector down low.)

[malibuguy]

I run a port matched WeaponR header on mine.

[SirDigby]

Originally Posted by mr_robot

I took at look at the stock and it's actually a header not a manifold.

For headers to provide gains, it would need to increase velocity. People are so concerned about "flow" and restrictions when exhaust is not really affected by neither too much as it's pulses rather a flow.

uh... header is just a slang word for exhaust manifold. they mean the same thing. reducing restrictions IS increasing velocity. exhaust pressure IS affected by restrictions. it does pulse, and it does it many thousands of times a minute. at 3000 rpm you are getting 6000 pulses a minute, or 10 pulses a second. weapon R has a vastly higher rate of scavenging than the stock manifold do to the tri-Y design. the scavenging removes more exhaust from the cylinder creating a richer a/f mixture and lowering carbon build-up on the piston surface.

[mr_robot]

FYI: https://m.youtube.com/watch?v=o9KPZZnMEHM

[Thirty-Nine]

DC Sports header on my Yaris. Worth the cash for me.

[SirDigby]

Originally Posted by mr_robot

FYI: https://m.youtube.com/watch?v=o9KPZZnMEHM

hahaha! what a funny video. i guess if the sales man want's to call it that.
the word "manifold" means a pipe or tube that branches off/collects together. the exhaust ports on the engine collect together at the exhaust manifold. it does not matter what it is made of. the intake manifold branches off individually to the intake ports. an aftermarket intake manifold that's made of a different material is not called a...? idk. to me, "header" is just a slang term. "manifold" means manifold as it does in electrical, as it does in HVAC, as it does in plumbing. idk. maybe i'm just crazy....

[james2007yaris]

Did aftermarket header installation have an effect on everyday fuel mileage?

My ass is 90% money saving commuter car and 10% fun go-kart