Car Noise - Why not Induction?

[aeropilot]

Alex_225 said:

I've wondered this for some time but why do manufacturers not enhance their induction noise rather than exhausts?

Noise regs......plus pretty much all petrol ICE cars are now turbo'd, and thus there is no straight to atmosphere induction run to have much in the way of induction noise, which is really a forte of n/a ICE engines.

[Leins]

The M3 CSL had a bit of induction noise going on

[havoc]

philrs03 said:

There is not a single engine note (in my opinion) better than a screaming 2.something with hot cams and a set of ITB’s. Epic. Especially in a convertible!!! Now my MX5 is functioning properly, nothing makes me happier than an 8000rpm rev limit, tall hedges either side of the road, and the roof down. Driving pleasure at its finest.

Ahem...this:-

Leins said:

The M3 CSL had a bit of induction noise going on

Best out-of-the-box* road-car 6-pot sound anywhere, possibly ever (although like-for-like fuel-injection doesn't sound as good as carbs). Followed by (for me) a Mezger GT3 and the NSX. Would very happily listen to any of those 3 engines being properly exercised all day long.

I'd also venture that a V12 with emphasis on induction (Mclaren F1 is exhibit A) can be even better.

V8s for some reason seem to major on exhaust - not sure if that's only implementation or if there's something in the cross-plane crank design.
V10s...too few to call, and too exotic. Need someone to lend me a few for testing...



* i.e. without mods - you're spot-on with ITBs, but they're slightly cheating!

[Pebbles167]

dvs_dave said:

Many many cars have induction noise enhancement systems fitted. A pipe connected to the induction hose leading to a diaphragm in the bulkhead under the dash is exactly that. An induction noise enhancer.

Any examples? This is the kind of thing that'll seay me in a purchase. I've not come accross it or even heard of it on anything other than the E85 Z4.

Some quick research suggests the Toyota GT86 has one also

Edited by Pebbles167 on Friday 17th May 00:35

[Alex_225]

Leins said:

The M3 CSL had a bit of induction noise going on

Funnily enough this model always sticks in my mind as I recall Clarkson driving one in a DVD I've got and him referencing the the induction noise of the CSL.

Pebbles167 said:

Any examples? This is the kind of thing that'll seay me in a purchase. I've not come accross it or even heard of it on anything other than the E85 Z4.

Some quick research suggests the Toyota GT86 has one also

Edited by Pebbles167 on Friday 17th May 00:35

The Focus ST had similar as it sounded far sportier inside the car than out. Thing is people like others to hear their exhausts, hence the popularity of the pops and bangs you hear. I just can't help think that a really purposeful induction note, when you're actually putting your foot down is preferable to a car popping and banging from accelerating from 5-25mph in first gear.

[Dannbodge]

Chris harris nailed this in one of his V10 M5 videos.

Exhaust noise is for everyone else, Induction sound is for you.

Exhaust noise is OTT and a nuisance, induction noise isn't.

I drive with my windows up 99% of the time so would rather induction noise, as I can actually hear it.

[padrc66]

Pebbles167 said:

Any examples? This is the kind of thing that'll seay me in a purchase. I've not come accross it or even heard of it on anything other than the E85 Z4.

Some quick research suggests the Toyota GT86 has one also

Edited by Pebbles167 on Friday 17th May 00:35

Definitely Mini Cooper S R56 (2006-2013) as i worked on it. Do a search for Symposer and you'll find loads - Fiesta/Focus ST, Land Rovers, Astons, etc

[Alex_225]

Dannbodge said:

Chris harris nailed this in one of his V10 M5 videos.

Exhaust noise is for everyone else, Induction sound is for you.

Exhaust noise is OTT and a nuisance, induction noise isn't.

I drive with my windows up 99% of the time so would rather induction noise, as I can actually hear it.

That's a good point, I mean lets face it the exhaust tips are as far aware from the driver as they can be but everyone else gets the noise shot at them haha.

That said, I recall putting an induction kit on my Clio 172 and pulling into the car park at work (circa 2004) and my mate who was also a car guy commented on how good it sounded under a bit of acceleration. So it can be heard outside. But I don't think it's anywhere near as lairy as exhausts can be.

[Hoofy]

Dannbodge said:

Chris harris nailed this in one of his V10 M5 videos.

Exhaust noise is for everyone else, Induction sound is for you.

Exhaust noise is OTT and a nuisance, induction noise isn't.

I drive with my windows up 99% of the time so would rather induction noise, as I can actually hear it.

I'm a bit confused here. I thought everyone would be able to hear the induction noise, too. When I go through tunnels, it drowns out my exhaust when I accelerate hard so the only way I can hear my exhaust mod is by slowly accelerating from say 28 to 30mph to reduce any induction noise.

[Llandudno]

New Yamaha MT09 has outlets on the tank especially for this reason!

https://www.motorcyclenews.com/news/new-tech/2023/...

[Hoofy]

As an aside, this is the thread I've been waiting for since I'd been exploring induction cones a few months ago! Never thought to post on PH.

aeropilot said:

Alex_225 said:

I've wondered this for some time but why do manufacturers not enhance their induction noise rather than exhausts?

Noise regs......plus pretty much all petrol ICE cars are now turbo'd, and thus there is no straight to atmosphere induction run to have much in the way of induction noise, which is really a forte of n/a ICE engines.

I'm not sure what you mean - you can definitely hear the induction roar on my Mk1 TT with its single turbo.

[swisstoni]

I love a good exhaust sound.
But I have the opposite opinion about anything from the other end.

[Haltamer]

Because it's far easier to subject everyone to a deafeningly loud exhaust

A £50 chop & weld job can make you the loudest Corsa 1.2 in the town centre - An actual intake costs far more and tends to throw more MAF codes / have greater impact on running. And it's just.. popular? to pop and bang.

I've always been a fan of intake before exhaust in terms of making more noise - On my first car, I had an Injen CAI that made a surprising difference:-
https://www.youtube.com/watch?v=kwMih7Pckb4

Not too bad a sound (To me at least?? ) for a 1339cc I4 Jazz Engine - Fairly smooth, inoffensive most of the time - You could get from 0 - 30 without making everyone at the roadside wince.

Never needed or wanted to touch the exhuast.

Similarly, with my newer Civic, I went for an intake before touching the exhaust - You get some interesting turbo noises, and the satisfying slurp noises before coming on boost.

As others have said (I frequently reference the Chris Harris bit above) - Exhausts are like farts, left behind for others to hear, but not so much for you:-

I now have a 3" Remus Valved exhaust, which with the valve fully open, amounts to a straight pipe - Sometimes I think, or passengers say: "That's not as loud as I expected" - If you stand outside however, you will quickly realise it is more than adequately loud.

I usually only open the valve up for intentional showboating (Receptive crowds in the daytime) or performance (Full open does have a notable impact on flow!) - Often when I'm driving though, I'll prefer it closed so I can take in some intake sound instead.

It is nice being able to choose with an exhaust valve as others say - I'm sure you could accomplish similar with the intake, but the complexity and packaging required for a giant array of helmholtz resonators and the likes operating with valved control and not impacting intake performance / AFM measurements significantly would make it infeasible.

[Simon_GH]

padrc66 said:

Definitely Mini Cooper S R56 (2006-2013) as i worked on it. Do a search for Symposer and you'll find loads - Fiesta/Focus ST, Land Rovers, Astons, etc

I’m pretty sure there’s something on my 1.5 182 3 cylinder Focus ST Line - there’s more 3 cylinder bark on the sport setting compared to the other two driving modes.

[Jon_Bmw]

Under load, induction noise from individual throttle bodies with a traditional foam sausage filter is savagely loud!
I happen to love it on my old 4 cylinder track car, but it is probably a bit too much to live with every day.

I think the CSL hit the sweet spot, relatively high revving straight 6 with ITBS with a carbon airbox. Certainly my S54 (same base engine as CSL) doesn't sound anywhere near as good with the same ITBS but with a conventional plenum, MAF and air filter housing.

[HazzaT]

I'm surprised it's not more common with how most cars are turbo these days as well. A nice intake will get some really satisfying turbo wooshes

[Alex_225]

swisstoni said:

I love a good exhaust sound.
But I have the opposite opinion about anything from the other end.

Haha no I think liking a nice exhaust note it's great too. I'm just surprised manufacturers haven't made more of induction noise when it can sound so purposeful.

HazzaT said:

I'm surprised it's not more common with how most cars are turbo these days as well. A nice intake will get some really satisfying turbo wooshes

Exactly what surprised me with my filter on my Saab. Even on a cold start and with just a 2k rpm blip of the throttle the sound is fantastic. Perhaps louder than some may want but I'm sure a manufacturer would just tweak an airbox so it sounded how they wanted.

[Lexmaster]

I'm also a big fan of some nice intake noise I do have a K&N intake with cone Filter on my ISF and i love it.
My Z4 E85 is not equipped with the soundgenerator tube unfortunately, i'm not sure if it's a worthy upgrade as they are getting harder to get and a bit expensive.

[aeropilot]

Hoofy said:

aeropilot said:

Alex_225 said:

I've wondered this for some time but why do manufacturers not enhance their induction noise rather than exhausts?

Noise regs......plus pretty much all petrol ICE cars are now turbo'd, and thus there is no straight to atmosphere induction run to have much in the way of induction noise, which is really a forte of n/a ICE engines.

I'm not sure what you mean - you can definitely hear the induction roar on my Mk1 TT with its single turbo.

What you are hearing isn't induction roar, in its traditional sense, of air being sucked through the carbs or ITB's into the inlet tract and ports.
The turbo/intercooler etc is situated between the air filter and the inlet tract, so what you are hearing the turbo induction sounds, which is not quite the same thing (in the traditional sense of the meaning)

Yes, its induction noise in the simplest of terms, but its created by very different aspects of the two distinct types of induction system....which is also why they are very different types of sounds.

[MustangGT]

havoc said:

V8s for some reason seem to major on exhaust - not sure if that's only implementation or if there's something in the cross-plane crank design.

Not all V8s are flat plane crank, most US V8s (until recently) were standard crank, Rover V8 based engines are also standard. To me, a flat plane crank V8 sounds rubbish, just as 2 x 4 cylinder engines sound together. My F348 was FPC, sounds really poor compared to my TVR, Aston, Jeep V8, Corvette or Camaro.