High pitched exhaust note

[WILSPEED]

Hey guys. A bit of a noob question. I have an SC with a NA 3.6 open exhaust which revs pretty fast but how the heck do some of these guys on the track have such high pitched exhaust notes, almost "F1" sounding???

For reference, one car in particular was a 911 track car with a NA 3.2 motor. I didn't get a chance to look underneath to check what it had specifically.

Is it just higher compression, exhaust piping, a combination?

Cannot find any info elsewhere. Any info appreciated,

Wil

[MBruns]

More than likely a 6 into 1 header system, a well developed engine has a different exhaust note vs. stock engines too
Mike Bruns

[stownsen914]

What Mike said. I've noticed that some of the dual center exhaust outlets achieve a similar sound to the 6 into 1. I guess having the two outlets together in the center of the muffler is essentially like a single outlet.

I ran a 6 to 2 to 1 single outlet open exhaust for a while on my 914/6 track car. Sounded pretty wicked. Definitely a higher pitch shriek kinda sound.

[WILSPEED]

I also have a 6 into 1 centered open exhaust definitely louder than stock but those other guys have a much higher pitched shrieking sound. Is it a high compression thing??

[stownsen914]

Originally Posted by WILSPEED

I also have a 6 into 1 centered open exhaust definitely louder than stock but those other guys have a much higher pitched shrieking sound. Is it a high compression thing??

Any other details you can share about the engine or exhaust on that car?

[WILSPEED]

The one in particular I remember , the car was GT4 class in POC I think, 3.2 carrera motor. He was very tight lipped even though it was only a DE (what the heck?). I just saw he had open exhaust 6 into 1 but I have that too? He did mention he had a remapped ECU though.

[WILSPEED]

It was a full blown track car, wide body, bi-wing , fiberglass bumpers and maybe quarters, lexan windows etc etc.

[pemz0r]

here is my 2.7 and it gets really high pitched after 5k

https://www.instagram.com/p/BK3VEi7AJif/

[WILSPEED]

Lol your laugh in the video! You have a great sounding car. Sounds wicked in the tunnel.

This other guy’s car sounded more F1 like, almost like a 991 RSR from GTLM or GTE class pro racing.

[smokintr6]

It seems like the small displacement engines that were really getting rapped out always sounded nicer than the 3.2 or 3.6 engines. The big engines seem to transmit those low tones and sound kind of tractor ish to my ears. My current exhaust on my 3.6 swapped Carrera is definitely a higher pitch... probably not F1 like you’re referencing, but it’s my favorite try so far. It’s B&B headers going straight into a flomaster chambered muffler.

https://m.youtube.com/watch?v=ezbE24oswZI

Sorry the sound quality isn’t stellar

[trond]

valve timing/cam type, ignition timing and mixture also affect exhaust note. More so with an open muffler. My engine sounds very different from my friends similar spec engine.

[Tippy]

High RPM allows for a higher pitch.

You might be hearing 8k+ RPM motors?

['76 911S 3.0]

Having a 6-1 with the primaries on the collector in sequential firing order should give you a high pitched sound like that, just listen to Tanner Foust's Passat drift taxi...this thing has 8-1 merge with the primaries in sequential firing order. Sounds like no other LS I've heard before

https://youtu.be/5Ot1qjHcruA?t=1096

[Neil Harvey]

Go to church, listen, then look.

Seriously, I did.

I was invited by the curator of the Walt Disney Concert Hall in LA to listen and look.

Get it?????

[BartdeBruijn]

Hi Will,

I remembered once looking (listening) for a new 6in1 exhaust and run into this....
It sounds not only on a RS high pitched ;-)

cheers,
Bart

https://www.youtube.com/watch?v=O6wuOUvDnzs

[stownsen914]

Ran across a video showing what looks to be a vintage 911 race engine running a 6-2-1 exhaust. It's just revving in the garage, but to me it sounds distinctly different than the twin megaphones setup. Revs it at :35.

[stownsen914]

Here's another one from a distance. Can't see the exhaust clearly, but it sure doesn't sound like megaphones.

[WILSPEED]

Yes the sounds in those videos are what I was talking about!

Ok, sounds like a 6 in 1 open exhaust and high rpm is how it’s done. Most 3.6’s I’ve seen don’t run as “hot.” Usually it’s the 3.4 or 2.7 hot rod motors I’ve seen.

(Another newbie question) Can you and HOW do you get a 993 3.6 non-vario to rev 8k and sound like those guys in the video ?

[KTL]

https://vimeo.com/14950324#t=1080s

Watch the 911 go by on the inside. It’s cstreit’s former racecar with a 3.3L non turbo engine with a 6-2-1 exhaust he cooked up with a resonator (think of the original 911 Euro premuffler shape) at the end of the system. It’s similar to a muffler that exits at the center of the car similar to what Scott posted

Here’s that same race from inside my car (nice camera position, right? ) at a different turn on the track. He comes by me on the inside after I wave

https://vimeo.com/15080050#t=1020s

Lastly, independent exhaust paths like megaphones isn’t necessarily going to get you that highpitch. Watch the start of that first video I posted. The dark blue 911 ahead of the camera car is mine (rookie noob and driving like it) and my exhaust setup sounds downright awful on decel/overrun. People behind me (well it wasn’t many people and they weren’t back there for long.....) often commented how loud it was and I think they were being nice. It sounded nasty back there. Inside the car it sounded fine

Here’s another listen to it from track side and you can also hear the difference in tone between mine and cstreit’s in this Gingerman video

https://www.youtube.com/watch?v=_a8pdgpaWec

[stownsen914]

Wilspeed - Getting a 3.6 (or any 911 motor) to safely rev to 8000 requires substantial internal mods and can be an expensive endeavor. You should be able to safely rev to 7000 though. If you are running open exhaust now, you probably have headers, right? I'd think that bolting on a single outlet open exhaust would achieve the sound you are seeking even if you don't rev quite as high - definitely a different exhaust note than the dual megaphones.

Scott