Turbo noises? BOV?

[MFNATIK]

I've test driven the M3/4 twice now and both times never could really pickup on any whooshing or spooling noises. Maybe it was being masked by the fake V8 sounds, but do you guys that own these S55 powered cars hear any of this?

Also, are there any aftermarket BOV systems to accentuate the noises? I don't want to sound like a fixed up EVO or STI, but just a hint of turbo induction/spooling should be evident with a TT powered car.

[Stage1]

I still have ASD on, but it does seem to mask the "natural" sounds of the engine/turbos. I flipped over to sport+ throttle and rolled the window down. Plenty of wooshing sounds

[CaryTheLabelGuy]

You can easily make out the twin turbos spooling-up, but you have to really build some boost. BMW has done just about everything they can to minimize this noise, for whatever reason. They've designed the intakes with very efficient silencers, for instance.

I think they should embrace the noises that come from a powerful twin-turbo set such as the S55. I prefer the spool of a turbo over the roar of a N/A V8 any day.

[dngo]

With the driver's window open, I can definitely hear the faint whistle of the turbos and the BOV. Not with the windows closed, though.

[Blksnowflake]

The turbos are pretty small, the car is well insulated, likely has a recirculating bov.....so you're not going to here anything really. After driving the car for 2k miles I can hear a hint of spooling, but if you want more you can replace the stock air filters or take out the charcoal liner which supposedly increases some intake and spooling sounds.

I owned an Evo X before this car and the spooling was minimal also but the single turbo was bigger and closer to the firewall so you could hear it better, it had a recirc bov so no blow off sounds either. I actually don't want to hear any whooshing sound from a bov, I think I've matured passed that, I focus more on the exhaust now, but hearing the turbos a bit louder would be cool, even my wife likes to hear it.

[Onewheeldrive]

Remove charcoal filters and upgrade to high flow drop in air filters and you hear plenty of gorgeous turbo noises.

[X2Board]

I do miss the spooling sound of my X5M's turbos. After my 1200 mile service on Monday, I'm going to code off active sound.

[MFNATIK]

Yeah, I'm not too much into hearing the BOV noises but getting some spooling/induction noises over the fake ASD would be nice. I had a GP Mini R53 that was SC and man, it would be really fun to get that thing going since the natural SC whine just let you know that it was boosting.

[Stage1]

I had a 14 STi with a cobb intake and box. That thing screamed as it sucked in air. Was almost as loud as the turbo spooling. As said above. BMW really did mute the sound (at least with windows up)

[DrtyJrze]

If you've really test driven an M and you can't clearly hear the turbo then either you were driving 10-20 MPH the whole time while engaging the throttle less than 15% or you have no idea what a turbo sounds like.

Even with the "fake V8" sound activated I can easily hear the turbos spool.

[MineralWhiteF80]

Solution:
Buy an HKS T51R turbo and your ears will thank you

or a single turbo with no blow off valve haha

[pikkagtr]

Fake v8 sounds? What have you guys been driving ? I can clearly hear the car as an inline 6 even with ASD on.
Maybe because I've owned a few inline 6 turbos in the past but this one sounds amazing.

[Pauly Walnuts]

Open windows and accelerate briskly from 1st to 2nd to 3rd. You'll hear them.

If you want your car have a loud ass blowoff valve to impress the kids at the local Cars and Coffee you may want to reconsider purchasing an M3/4.

[CaryTheLabelGuy]

The S55 is not equiped with a BOV (Blow Off Valve). It has what is called a Recirculated Diverter Valve. Instead of venting boost pressure to atmosphere (BOV) on throttle plate closing, it recirculates the boost pressure back into the system.

If you install a BOV on a MAF(Mass Airflow) based system, the release of already metered air will cause the ECU to freak out and possibly stall from an over-rich condition every time you lift the throttle.

You can sometimes get away with using a dual-vent BOV like a Go Fast Bits Stealth FX BOV and allow enough metered air to be recirculated, whilst still venting enough to atmosphere to give you that sound you're looking for.

As far as I know, nobody has figured out how to or if it is possibly to install and dual-vent BOV on the S55.

[MineralWhiteF80]

Can you install a blow off valve vented to atmosphere in a new M3? Absolutely.

Is it a good idea? No, no it is not.

You are forcing the car to run rich during shifts and lifting off the throttle, which creates poor throttle response. If a cool noise is worth making your car run poorly, then go for it.

Depending on the design of a recirculating valve, you can simply disconnect the return hose going into the intake pipe, plug the hole in the intake pipe, and make the valve vent to atmosphere instead. You will have your blow off valve sound then.

the vast majority of factory turbocharged vehicles use a MAF sensor. It is these same cars that everyone puts BOVs on, it just reduces the driveability/performance of the car.

Once you drive a MAF car with the valve vented to atmosphere, and then drive it again with it recirculated, you will want to keep it recirculated because the car drives so much smoother and better.

[Blksnowflake]

Originally Posted by DrtyJrze

If you've really test driven an M and you can't clearly hear the turbo then either you were driving 10-20 MPH the whole time while engaging the throttle less than 15% or you have no idea what a turbo sounds like.

Even with the "fake V8" sound activated I can easily hear the turbos spool.

What, have you driven an M3....whatever that sound is, it isn't a V8.
I prefer the tt I6 sound more than a V8 anyway, it sounds more euro and exotic.

[forza1976]

Originally Posted by Blksnowflake

What, have you driven an M3....whatever that sound is, it isn't a V8.
I prefer the tt I6 sound more than a V8 anyway, it sounds more euro and exotic.

What, you are saying the high revving S65 wasn't euro enough? Have you heard any high revving N/A euro cars lately. They all sound pretty damn good.

[3er]

Tune = More turbo-y noises!

[nicknaz]

My understanding of the articles about our s55 engine said the air that would go to a bov is used as part of the anti lag system to keep the turbo spinning when you lift or shift. Why mess with anti lag for sound?

As for hearing the turbo spool, i definitely heard them on the autobahn this week

Try flooring it in 4th on the freeway

[TheRealOrosie]

I could always hear them with the windows down. They have gotten MUCH louder since tuning the car, especially in Sport+

[fortressmaximus]

If you accelerate hard you can hear the turbo spool sound, but it's not a super loud whistling sound like some of the other turbos out there.

[MFNATIK]

Thanks for all the helpful responses guys! Will definitely not mess with a good thing. Was only curious to see what/why/how these cars were setup. Sounds like we have some real experts on the TT setup on here so its good to get some technical knowledge.