Why do they need a powerdome hood?

[artar]

The engine doesn't sit high. The 8 individual throttle bodies connect to the plenum which has vertical velocity stacks within it. This requires some height to perform as designed. I'm sure they could have made the plenum shorter but perhaps doing so would sacrifice high-rpm performance.

[MSPORTWORLD]

I don't know the BMW "Official" Engineering reason why the Powerdome is more than a cosmetic feature and actually provides a performance advantage. I will do my best to take a Berkeley Engineering wag at the answer.

When BMW designed the M3, systems engineering processes were in effect throughout the entire design, however, when it came to the powerplant design they had to make sure the engine performance was optimized. In order to squeeze the most power out of a NA V8 they had to make sure such minute details such as the length of the individual throttle bodies provided the best performance and would not be a compromise based on how the motor needs to fit in the car.

When the motor was fit into the chassis it was integrated in a way so that the center of mass of the motor was as low as possible in order to keep the center of mass of the overall vehicle low as well. After determining the placement of the motor in the vehicle they then continued to integrate such aspects such as the hood and what resulted was a functional powerdome.

The E46 M3 although it had a powerdome it was not functional because the ITBs run perpendicular to the block as opposed to extending vertically upward.

I apologize if my automotive rambling makes no sense. It makes sense in my head as I am writing it and I would rather not go back and proofread to make sure it actually makes any sense at all.

[ctown113]

Originally Posted by 5erman

I am not understanding why bmw could not contain their "massive" (jk) 4 litre V8 in the engine compartment without it sticking up so high as to require a domed hood. I like the dome cosmetically but functionally its sad that the engine sits up so high, especially for such a compact lightweight engine.

Much smaller cars stuff MUCH bigger engines in without the need for a special hood.

I guess I am wondering why did they not put the engine lower?

So would you rather the hood be flat and plain like a 335 or 328? Who cares? It looks cool as sh*t and separates the ///M3 from the other 3 series models amongst other things. If it bothers you so much, why dont you get a 335i or apply for an engineering job at BMW and redesign it the way you like it? LOL.. this is a useless thread but I had to
respond. You obviously don't own an ///M3 and if u do, you're an idiot for posting this question~

[BMWBoss]

Who cares?...it looks sexy

[Chowster]

[EIS 9]

Well I'm thinking it has the powerdome for the same reason that I wear my jock strap on the outside. I also bought a diesel lawnmower with a powerdome. That way, when I'm mowing my lawn with my car parked out front, all the neighbors know we're part of the same collection.

snik.........

[Definitive]

I like my bulge and wish it was even bigger!!! ROFL



D

[UNNATRAL]

Originally Posted by Poleposition

really?

[mdosu]

Originally Posted by sensi09

Even if it's necessary, I think the size of the bulge is a bit exaggerated. I do believe they could have made it smaller if they wanted to.

I like the powerdome, but at the same time, I don't think it completely flows from some angles.

I'm going to proceed and take it to this level...
My powerdome in my pants follow the same concept.

[ihyln]

The car would look pretty stupid with one vent on the hood, no?

[EIS 9]

only if they put it on the wrong side.........

[bunnn]

I think a lot of you guys aren't reading this properly. OP obviously doesn't mind the bulge. He was really only asking on why BMW decided to put the engine at that height thus creating the bulge, when maybe they could have lowered it a bit more and avoided it. I haven't gone under the car yet but I suspect any lower may be dangerous due to road debree

[jeff@autocouture]

It must be that time of the month

[chd2]

The engine mass sits low, but as others have said, the throttle body assemblies coming off the intake side of the heads sit higher than the head covers. Add the intake plenum, and there's your dome. If you look under the car, the motor sits pretty low, so I don't think it was out of laziness in engineering.

[Brosef]

Originally Posted by 5erman

I am not arguing asthetics. It is clearly needed for clearence on this car, not the e46 where it was just cosmetic.

I actually have researched the engine and the engine is not the problem, it is why bmw could not have packaged it more neatly.

Now stop acting like you are an engineer and clearly you do not know the answer so dont fill the thread with garbage posts. thanks

Wow, what an insecure douche you are. Unlike all the posts above mine that were basically just laughing at your ignorence, I actually took the time to write the correct resoponse (as was confirmed by other subsequent posts), so there's no reason to be a hardass. Don't throw stones if you live in a glass house (the figurative glass house being your inability to use the search function in this case).

[Dengel]

Because it looks fcking badass. Need i say more?

[3XTR3M3]

Originally Posted by Dengel

Because it looks fcking badass. Need i say more?

Apparently, yes.

[E46 Dave]

Because women always look for the biggest "bulge"

[JCtx]

Summarizing:
-Engine does not sit low; it's the individual TBs that make the height unusually high.
-Only way to make engine sit lower would be a dry sump ($$$$), and not by much.
-There's hardly any clearance between hood and plenum, to the point you can't even fit a hood insulator, so bulge is the minimum size possible.

[bmwm4f82]

The power dome is there for one reason only - to leave enough space between the hood and engine to provide enough deformation zone area to meet governments pedestrian collision protection laws.

[mrad01]

...also, the amount of air which the "small" M3 V8 spinning at 8400rpm is probably a bit more than your average yank tank V8 which might be 6.2 litres, but only spins up to 4000rpm. Not as much air required I'm guessing.

[Ken37.73]

Apparently they tried to lower the engine but something got in the way. What was this they called it, oh yeah, it was the ground.