Why FA20 engine is noisy?
 

Is it because the way it is designed? Or its a characteristics of any Boxer Engines? Does WRX STI (ej20/24) also noisy like this one?

Dual injection, horizontal, over head cam, thinner exhaust manifold material, less sound deadening everywhere, etc.

small tractor engine

How about STI's engine?

Pretty sure it's the Twins which are noisy, not the engines. All engines are noisy, they are just sound-insulated better. But sound insulation adds weight and reduces the raw feeling of the car, so the Twins don't have much.
I'm sure if you up the sound insulation on a Twin to a similar level as a regular commuter you'd get similar noise levels. Alternately, compare a running engine with the hood open across different engines to see if the FA20 is really any louder.

Sound tube, minimal noise insulation to reduce weight.

Same thing. You just hear it more in the Twins because of the dual injection and lack of soundproofing.
Most cars are so soundproof now that they just hide the sound that they all make.
You want to hear noisy take a base model 60s Dodge Dart with steel door panels and dash with no factory carpeting for a spin! The Twins are like driving a Rolls in comparison.

Isn't port injection only added at low and high RPM? Wouldn't then the bulk of operation be direct injection only? I remember seeing a graph detailing the breakdown between direct and port injection, but can't find it now...

I recall seeing that one too. Can't find it either.

IIRC, the car starts on port (maybe because the DI pump needs a moment to ramp up fuel pressure? It's mechanical, right?), and then always uses DI as soon as it becomes available. Port is only active as a complement below roughly 4 500rpm. Past that, it's DI only.

Some Ford engines are the opposite, using a majority of port with DI as a performance complement. Which allows them to idle on the quieter port system.

But as others pointed out, the FA20D's a fairly agricultural engine with a rather high degree of complexity (4 cams & 8 injectors on only 4 cylinders), plus the car lacks deadening and is running on a platform that wasn't created for luxury.

I *think* the EU cars are a little quieter due to a more restrictive rear muffler and more hood sound deadening, though I guess it mutes them more than it refines them.

Yep. And you can really easily hear when they kick in and out.

I love mechanical noises and it gives me a feel of owning a sports car. But they are so loud and every single days I believe I can hear new types of noise. Due to lack of automotive mechanical knowledge, it just scare me and push me to believe something is wrong. On the other hand, many peoples told me the engine doesn't feel like pickup truck engine rather than sports car engine.

They have so much horsepower the sound slices through the engine bay

my 2015 Legacy at cold startup, is louder inside the cabin than when I had my BRZ stock under the same conditions.

sometimes you have to quantify what exactly is "noisy", because context matter.

I have excluded anything related to rattling including cabin. I have compared it to my friends 180SX, my 86 has 3 times louder noise than him.

The 86 is three times better.

I really hope the car is bone stock.

You meant that 180? Surprisingly, it is fully stock. The owner is female japanese and imported it from japan with only NZ$6000 around 17/18 years ago

No, your "loud" 86.

Yes it is. Total stock and only 9000 KM on it.

There are times this engine reminds me of my old Benz W123 turbo diesel. It makes similar tractor noises. It's endearing for me but i can see why it wouldn't be everyone's cup of tea. It certainly vibrates a lot at 7000 rpm lol.

The noise tells you it's running.

This is deep

my brother used to have a stick shift jeep patriot. it was in the way one day we were all at the parents house, so i offered to move it, curious to play with a different stickshift vehicle.

i started it, but never heard the engine running after the starter disengaged. but the RPM needle then hovered at 900, so i assumed it was running.

it was then that i learned that i drive and shift my car almost entirely by the exhaust note.

trying to move that patriot was like a car racing game, but muted. and i had to coordinate gas and clutch to make it move.

after 30 seconds of trying to gently rev it like i normally would, i gave up, spun the gauge to 3,000 rpm where the motor started sounding like a bath fan running at half power, stirred the stick of lukewarm butter in the center console to a position that vaguely felt like first gear, and then let the clutch out slowly until it moved where i wanted it.

i never offered to move his jeep again.

by contrast, my car in stock form might as well be a straight-piped v8.

I can actually hear the engine noises at night from at least 100m away.

I kid around but I know that struggle. So quiet it takes a while to get used to it.

First test drive I remember looking at my wife and saying "Man, this thing's a bucket of bolts."


I got over it.

I don't understand what you'll are talking about, my FR-S is quiet - :iono:

so is your wife if you forget to turn your hearing aid back up after driving!

Compared to most modern cars, you feel and hear more in the twins. It can be a little unsettling at first, and it makes you realize how isolated most cars are from the driving experience. The faster you drive the twins the better they get. I think of them as fixed roof S2000’s. Or like a modern FD RX7. Just enjoy driving your car and don’t sweat the noises, they are really well built and as reliable as a sports car can get.


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Yep!
If the car stops making the noises is when I would be worried.

The FA20DIT is easy to tune and mod, but that can start to push the rods towards their safe upper limits. That said, the FA20's are solid engines overall that provide a solid balance of reliability, performance, and efficiency. Maintain them well and you'll likely have a good experience for many years to come.. .

Where is the spam link? Not ready for it yet?

wasnt coded in time for its deployment

It's not noisy compared to other small sport coupes with NA 4 cylinder engines.

Yes it is, rev out an ND miata to redline, either gen, it is much smoother and quieter ( i know you said coupe but close enough). IMO the noise though is a big part of the charm of these cars.

poo car

Aaaand reported

https://i.imgur.com/R2kitjr.jpg

Clever girl.....