this is a gt3076r


http://www.youtube.com/watch?v=F1KRwD0kdEQ

 

meh, i pick my turbo based on peformance matched to meet my goals, not how they sound.

 

As should everybody

 

i have fitted a fake dump valve to sound like I am turbocharged because I can't afford a real turbo setup...

Does that make me a loser?

 

the ball bearing turbos I've had in my Audi both have the sucking/screetching sound, not the traditional whistle sound of the journal bearing turbos. I had a GT28R, now a GT28RS. So my assumption is that the ball bearing turbos sound different than the journal bearing variety in the way that yo describe. I notice at low boost (13 psi) the sound is more like sucking while at 22 psi it gets a higher pitch to it.

 

when i had a stock exhaust, i could hear the turbo slowly start to spool, and as it really spooled it sounded very nice, kind of like a internally wastegated turbo, but then the dumptube would open up.

Now the turbo spools much faster and the i hear the exhaust alot more! Since upping the boost, the turbo has completely changed its sound... much more visceral and manic. I will post some vids!

 

hahahaha, I knew someone was going to chime in and say that comment. How about this. You call me when you want to size a turbo and I will help you through some of the theory newbie! :-) Nah, I'm just being a ass....but really if you paid attention to my orriginal post weir you would see that I am asking for the theory behind the sound more then which turbo makes what sound. Gather information first, then I can start to deduct reason out of it. Unless you already know the theory and priciples behind why certain turbo's whistle and others don't........

IN THAT CASE EDUCATE ME ALREADY INSTEAD OF JUST SAYING DUMB COMMENTS!!!
I expected more from you Aaron.

But now your wondering why I know you name.


Did you ever get that flange for a SR20DET made?

J. R.

 

Ray K. I agree with you. I have also noticed that the non-ball bearing turbo's do wistle more......

Hmm...I wonder what that has to do with it.

While someone mentioned above its as easy as the rpm of wheels, but I think there is WAY more to it then that. I will explain my reasoning more once this thread matures a little more and we have some more info to work with.

I don't want to throw my theories out there just yet until I am sure about all the information out there.

J. R.

 

Then explain your reasoning. Everyone else is throwing ideas out, some more eductated than others. What makes your ideas so special that you feel they don't deserve to be shared until this thread "matures"? You started the thread, why do YOU think there are differences in turbo sounds with different turbo designs?

The pitch of the sound coming from a turbocharger is just about completely dictated by the rotational speed. The faster it spins, the higher the pitch. Period.

A large turbocharger operating at low pressure will be spinning relatively slowly. The sound of fast moving air/wastegate noise, exhaust may far outweigh sound generated by the spinning turbo. A small turbocharger operating at high pressure will be spinning relatively quickly. This may come through as a very high pitched whistling.

Here's a wrench in the gears...

The upper limit of the audible range of human hearing is about 20,000 Hz or 20K cycles per second. If a turbocharger compressor wheel is comprised of 20 vanes, and the wheel is spinning at 120,000 RPM (which is 2,000 rotations per second), a blade will pass the compressor housing cut-water at a frequency of 40,000 Hz. That is, one single blade will pass the most restrictive part of the housing (the location of a massive pressure stagnation point and more than likely, a few shock waves) at a frequency of 40,000 times per second. Thats two times higher than our ears can distingish, therefore...we can't even hear it.