Why are some turbo's louder than others? (not talking about BOV)
 

This is something that I've been wondering about for a while, but never really got a good explanation anywhere else...

Why is it that some turbo's are louder than others?

Is it simply the size? The bigger it is, the louder it is?

I've heard it has something to do with the style of the wastegate...
Any truth behind this?

I want to make it a point to mention that I am NOT talking about the BOV.
I know most people always want to know how to make thier BOV sound louder, but this isn't what I'm talking about at all.

Here is a video clip of a single turbo Supra which has one of the nicest sounding turbo's I've ever heard.
What would make the spool so loud like that?

http://supra.sysadmin-racing.com/videos/temp/cruise.wmv

I've done quite a bit of research and have read Maximum Boost numerous times and own a Subaru Sti, so I know a little bit about how turbo's work, but I just have never understood why some are so much louder than others.

I am talking about the sound of the turbo spooling to be exact.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

BB (ball bearing) turbo's are unique in sound, and louder.

A lot has to do with the shape of the compressor blades.

14b/t25/lots of t3's have straight finned, identical blades. They are boring and not very loud.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

also the turbos are probably the size of ur head! :-*

Re: Why are some turbo's louder than others? (not talking about BOV)
 

hahaha ;D

I wouldn't doubt it.

It's wierd because even some small ones are just really loud.
I've noticed with my Sti that you can't even really hear it at all with the windows even down a little ???

Re: Why are some turbo's louder than others? (not talking about BOV)
 

a lot of it has to do with the exhaust and filter set up. i have straight 3" exhaust with no cat/resonator/muffler and no filter on my turbo at all and the turbo whistles louder than a damn mack truck.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

You would figure the exhaust would drown it out, that's strange...

Maybe it has something to do with the filter then, because most of the time a wide open exhaust would make it harder to hear the turbo (or anything else for that matter)

Re: Why are some turbo's louder than others? (not talking about BOV)
 

i have a dinky t25 with an open dp, but you can hear this little fucker whistle from almost a block away at wot!!! (no joke)

Re: Why are some turbo's louder than others? (not talking about BOV)
 

There are about 3 things you can do to make the turbo you have louder.

- hard metal intake

- open inlet on teh turbo (no intake pipe or filter)

- straight through exhaust (no cat/straight through muffler)

Re: Why are some turbo's louder than others? (not talking about BOV)
 

So it must be because of the plastic intake (stock).
It probably makes it real quiet.

What do you guys use to put over the turbo inlet?
I've seen some people use something that almost looks like a regular screen door material...

Re: Why are some turbo's louder than others? (not talking about BOV)
 

the open exhaust makes it louder b/c the turbine wheel is right at the beginning of the dp, so if there are no restrictions, the exhaust acts as a megaphone sort of and amplifies the sound of the turbine wheel spinning, that paired up with as little as possible restriction on the intake allows the comp. wheel to be heard more also. you'll hear the turbo whistling even when it's not spooling in vacuum because the wheels are still spinning even when you're not building boost.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

Stock plastic turbo inlets have baffles and what not that quiets it down a lot. My T3 with an open pipe is wicked loud. I also have an open 2.5 inch exhaust.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

What do you mean by open pipe?
On the intake side or exhaust side?

Re: Why are some turbo's louder than others? (not talking about BOV)
 

my friend bought an srt-4...had the stock intake on it and he put an injen intake on it...now u can hear that thing a block away...try doing an intake

Re: Why are some turbo's louder than others? (not talking about BOV)
 

I have plastic intake arm and one of those cheap ebay HKS style filter with 2.5" exhaust and no cat. Sucker spools like a one of those damn semi trucks... maybe not that loud but you can hear me quite a distance away.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

The K&N Typhoon is extremely popular with the Sti's and it will make the BOV much louder, but everyone says that the sound of the turbo is no louder.
I can't figure out what would be making it so quiet ???

Re: Why are some turbo's louder than others? (not talking about BOV)
 

it has to do with the turbo size and exhaust setup. a smallet turbo likea vj-11 will make more sound sooner than a t3.. simply because its spinning faster.. most turbos operate in acess of 150,000 rpm.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

I believe you that it does have to do with the size and exhaust(as well as intake) setup, but the second half of your statement is kind of pointless to be frank...

Re: Why are some turbo's louder than others? (not talking about BOV)
 

if he wants to feel smart and tell all the turbo guys how fast turbo's really spin..then let him lol

Re: Why are some turbo's louder than others? (not talking about BOV)
 

ive been wondering the same thing, my friends t3 .48/.42 with a open downpipe is ------ loud, nice wistle to it.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

mine is pretty loud. 3 inch dp with 2.5 exhaust thru a magnaflow muffler. its almost annoying. i have a U shaped intake on it with filter as well, tapped with a fitting for my PCV setup

Re: Why are some turbo's louder than others? (not talking about BOV)
 

my little greddy is loud as a f'n mack truck!

Re: Why are some turbo's louder than others? (not talking about BOV)
 

Any chance you guys could post some little clips of those puppies in action?

What did you guys think of the Supra clip?
Sounds pretty sick, huh?

Re: Why are some turbo's louder than others? (not talking about BOV)
 

i've noticed that non-bb turbos sound more like a high pitched whistle and BB turbos sound more woooshhhhieee.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

http://www.we-todd-did-racing.com/we...ZmQzMXk1NDE%3D

My piecer. 14b, 2.5" exhaust.

I recently made a cold air intake that goes into the fender well.
https://www.homemadeturbo.com/forum/...3335#msg473335
It whistles alot louder now, then when I had a HKS style filter directly on the turbo. I don't know how much that has to do with the metal pipe, and how much it has to do with the filter being in the fender, which is alot less insulated than the engine bay. But the spooling noise is alot louder now.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

im running a 14b with no filter and a 2.5" exhaust. pretty audible.

just about anything on open downpipe is pretty loud.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

SC61's boosting in the teens sounds like a god damn 747 =)

Re: Why are some turbo's louder than others? (not talking about BOV)
 

By "open downpipe" are you talking about just a downpipe with no exhaust (no muffler or anything)?

Re: Why are some turbo's louder than others? (not talking about BOV)
 

Re: Why are some turbo's louder than others? (not talking about BOV)
 

my exhaust is completely open 3". not cat, no resonator, no exhaust, and yes, it makes the turbo MUCH more audible...

http://www.draglab.com/hmt/projektegdizzle/dp4.jpg

Re: Why are some turbo's louder than others? (not talking about BOV)
 

Yup, most people use whatever kind of screen they can find. Screen door material works well.

But, the only downside is, you don't get any filtration and you can suck in dust, sand, dirt, or whatever... and that's not really a good thing.

Re: Why are some turbo's louder than others? (not talking about BOV)
 

I really don't understand why people don't put proper filters on their turbos, yet when they run N/A they do?

Boost or not, the motor is sucking in a bunch of CRAP

Re: Why are some turbo's louder than others? (not talking about BOV)
 

Wow, I can imagine it would.
What do u use on the intake side?

Re: Why are some turbo's louder than others? (not talking about BOV)
 

unfortunately nothing right now :-[ not by choice though, my turbo has a 4" inlet and i can't find a filter big enough to fit it. it's a brand new turbo and only has about 1k miles on it, so i don't think it's done any harm *yet*, but i'm ripping my ps and cc out so i can get a 4"-3" reducer on there and have room to make a nice little intake. i prefer not to run anything, but i don't want to ruin or shorten the life of my brand new little monster :P

Re: Why are some turbo's louder than others? (not talking about BOV)
 

I had a problem with finding a specific filter size on my older car which had a diy intake and someone showed me a page from K&N's site where they actually offer pretty much any size cone filter you can imagine ;)