Random Ecoboost Discussion

"K-Roll-PorscheTamer" (k-roll390) 02/05/2016 at 18:24 • Filed to: Questions

1

17

For some reason, I’m pondering this motor again...There are some things I’m trying to figure out from an engineering standpoint, and some other stuff.

First off, I couldn’t find an answer or understand this, but what is the point of a “headifold”, combining the cylinder head and exhaust manifold into one unit? What are the benefits of doing so, and is that why 4pot EB motors sound the way they do compared to “traditional” turbo 4pots?

And for that matter, what exactly is that difference in noise? Take a GTI and EB for example:

Opposite Locksmith > K-Roll-PorscheTamer 02/05/2016 at 18:34

1

Boooooost

Aaron M - MasoFiST > K-Roll-PorscheTamer 02/05/2016 at 18:37

4

A “headifold” reduces costs. You just went from two cast pieces where one or both need finishing machining to one cast piece where you only need to do finishing on one port, the turbo inlet. Honda went to integrated manifolds also for the same reason.

As for difference in noise...sorry, can’t hear it. Yeah, a GTI and the Ford sound a bit different, but there’s nothing I can hear that sounds unique in any way. Do keep in mind I’m coming from a Subaru, the only 4-pot that sounds good. :-p

K-Roll-PorscheTamer > Opposite Locksmith 02/05/2016 at 18:38

0

That doesn’t answer anything. -_-

JawzX2, Boost Addict. 1.6t, 2.7tt, 4.2t > K-Roll-PorscheTamer 02/05/2016 at 18:39

4

the main advantages of the “headifold” are reduced weight, more compact packaging, reduced part count, simplified assembly, shorter exhaust run to the turbo, making for better transient response and less turbo lag, and finally, by having the turbo closer to the top of the engine all charge piping length is reduced.

Other possibly valid points are better heat transfer both ways (the turbo stays cooler and the head heats up to operating temperature quicker), reduced 1st catalyst heating time (goes into closed loop quicker for reduced emissions).

I have no idea if this directly effects the sound of the engine, or if this is a result of other factors like valve timing and overall exhaust tuning.

K-Roll-PorscheTamer > Aaron M - MasoFiST 02/05/2016 at 18:40

0

That’s all it does? Reduce costs?? I thought there was some sorta engineering performance reason....That’s kinda bumming.

And of course boxer 4s are the best sounding 4s; they’ll never sound like god damn fart cans.

Opposite Locksmith > K-Roll-PorscheTamer 02/05/2016 at 18:41

0

But does it?

K-Roll-PorscheTamer > Opposite Locksmith 02/05/2016 at 18:43

0

Doesn’t it?

Aaron M - MasoFiST > K-Roll-PorscheTamer 02/05/2016 at 18:43

3

There’s two engineering benefits: size and to a lesser extent heat transfer. When Ford designed the head, cost came first and turbo packaging second...the heat transfer benefit is more of a bonus.

bob and john > K-Roll-PorscheTamer 02/05/2016 at 19:04

1

what JawsX2 said. better packaging, reduced part, easier to assemble. and one less gasket to worry about.

dis-advantages: well, cant easier swap headers, turbo changes will be harder, and if it fucks up, its a MUCH more expensive part to replace.

noise? i’d doubt that. there are a LOT more differences from the mustang engine to the 2.0L in the GTI.

Jayhawk Jake > K-Roll-PorscheTamer 02/05/2016 at 19:14

1

It does if we say that the added stress of boost is better handled by a combined header/manifold

DoYouEvenShift > K-Roll-PorscheTamer 02/05/2016 at 19:22

0

The headifold is pretty common now it seems. For reasons stated already. I really havent noticed the difference in sounds.

Big Bubba Ray > Aaron M - MasoFiST 02/05/2016 at 19:46

1

“the only 4-pot that sounds good”

You haven’t heard a 500 Abarth exhaust then!

bryan40oop > K-Roll-PorscheTamer 02/06/2016 at 08:50

0

Less turbo lag. That’s the main reason.

TheNeonDriver - Now with More BMW! > Opposite Locksmith 02/06/2016 at 11:23

1

More to the point, lack of lag

Opposite Locksmith > TheNeonDriver - Now with More BMW! 02/06/2016 at 11:49

0

Isn't that what I said?

TheNeonDriver - Now with More BMW! > Opposite Locksmith 02/06/2016 at 13:20

0

Ostensibly

uofime-2 > K-Roll-PorscheTamer 02/08/2016 at 12:07

0

one reason they sound different which is caused by the integrated manifold is the different exhaust primary lenghts. since the turbo mounts in the center, the center two exhaust runners are shorter than the outer two.

The firing order plays a role too, I assume both are pretty conventional for a 4 stroke 4 cylinder (combustion event every 180 deg). Depending on how it fires wrt the short and long runners it will end up with a sort of uneven “beating” sound because the phase shift the the different lengths causes on the frequencies of the firing events.