Im gonna ditch the non-seq twins and go single and I also love the sound of loud turbo spools.
heres a vid for example:
http://www.youtube.com/watch?hl=en-GB&v=qzNdJ3LPu4Y

I know the size matters but is there anything else that contributes to the noise? like BB vs. GB, if the turbo has a shroud on it, etc. do any of you guys have personal experience or considerations on a loud single turbo? I know it'll make more power than the twins but having that whine would be awesome.

 

The size of the slit in the Anti-surge cover.

 

That and running no filter. Filters dampen the noise. Ball bearing turbos also tend to have more of a whistling noise or w/e.

 

I would suggest selecting your turbo based on performance, not the noise it makes

 

Unless the turbo sounds like a supercharger then you should be a little worried

 

anti surge housing or ported shroud it is called. that is what makes the loud whine on turbos.

 

i see. thanks guise

 

Thats also the HKS T51R SPL... one of the only turbos in the world that sounds like that.

 

hey u can always record the sound of the spooling of this video, install a big *** soundsystem and playback it.. lol

 

Borg Warner's extended tip is loud too. Mine starts whistlin even before i get into boost.

 

To note that turbo is compressor surging when they let off. Not good for the turbo.

thewird

 

I believe to an extent that

more boost pressure = louder, more audible spooling sound

 

I would concure on the above statement.

seams like g16s running 25psi on an eclipse is louder than my to4b running 8psi.

but maybe I just cant hear it over the exhaust.

 

Can't you just run your car to be vented to atmosphere too? As well as just having dumps for your exhaust?

My daily driver is a 400awhp Stage 3 S4 and the K04 turbos are not big turbos but I have cutouts right before my cats and you can hear the whistling/spooling of the turbos before you're even in boost. I can't really hear them when I got WOT though, my exhaust overpowers it.

 

what you are hearing on the audi, is the turbine side. they are all talking about the anti-surge housings.

and yes, more boost will be louder because the turbo is spinning faster and sucking in more air, kinda a no brainer...

 

I had a customer do a back to back dyno and the anti-surge housing picked up 21rwhp. The only thing that was changed was the housing, pulls were back to back. Dyno operator was not surprised, he expected it..

 

Power increase would only occur if the engine was unable to consume all the air that the turbo was trying to push into it. In that case the engine would gain power from eliminating the constant fluctuations in boost as the turbo was surging. Running a ported cover on an engine that does consume all the air the turbo feeds it, would have a small loss in power, due to reduced compressor efficiency. This is assuming all things equal, and does not include a ported housing with better aerodynamics.

Bottom line: If you pick a turbo that's too large for your engine, you may benefit from an anti surge housing. Or, if you like the sound it makes, then the impact on performance would be small. If your turbo is sized correctly, then a ported housing would hurt performance by a small amount.

Information from Garret:

"A Ported Shroud compressor (see Fig. 2) is a feature that is incorporated into the compressor housing. It functions to move the surge line further to the left (see Fig. 3) by allowing some airflow to exit the wheel through the port to keep surge from occurring. This provides additional useable range and allows a larger compressor to be used for higher flow requirements without risking running the compressor into a dangerous surge condition. The presence of the ported shroud usually has a minor negative impact on compressor efficiency."

And a good video showing compressor surge (not the kind when running without a BOV) http://videos.streetfire.net/video/T...sor_163406.htm

 

I miss my old T51r