The Toyota Landcruiser Owners Club

[nick j]

Never really driven with the windows down until this warm weather so never noticed the whistle sound on start off before! any idea what it is??

[Google]

[uk_vette]

Turbo spooling up.

[nick j]

Is it a problem?

[uk_vette]

Don't think so,
Mine does it, as well as a few others.
Not just a LC thing, my TDCi Mondeo did it much louder than the LC.
Actually, I don't hear it any more, it just fades into the back ground.
I only hear it if I am listening for it.

'vette

[leon]

yeh the turbo should whistle it dose on all turbo's some louder then other's
A turbocharger consists of a turbine and a compressor linked by a shared axis. The turbine inlet receives exhaust gases from the engine exhaust manifold causing the turbine wheel to rotate. This rotation drives the compressor, compressing ambient air and delivering it to the air intake of the engine.



exess air is vented through the " dump vaule back in to the air intake when you change gear  ( closed circuit vaule ) the other kind is a open value witch dumps the air out side the air ways  witch gives the boy racer's the "wooooosh " sound you get on sport's cars with turbo's
without a dump vaule the tubo stall's with back presher and has to "spool up again" (boost) Older turbo cars can benefit from having a "dump vaule" added prelongs turbo life and cut's down on "turbo lag "

wastegate : once the engine hit's a pre set PSI the extra pressure is passed through the wastegate
Many diesel engines dont have any wastegate because the amount of exhaust energy is controlled directly by the amount of fuel injected into the engine and slight variations in boost pressure dont make a difference for the engine.

diesel engines  run a low pressure turbo say 0.6-0.8 bar were a high pressure turbo can run at 3.0 bar+ ...a impreza turbo run's at about 1.1 bar if i remeber  



thats it in short  

I could go on and on ...bilt a 400+ bhp 2.0 4x4 Impreza WRX hand made cosworth pistons etc etc  in the late 90's before every one had one   0-60 under 4sec's melted/blow it up 3 times before i got it wright  

With all that going on your going to hear noise from the turbo ...if you dont then your in trouble  
_________________
Should I have these bit's left over ?
1998 V8 LC Amazon VX work in progress
2008 pug boy
2009 pug boy
2010 pug girl
         ^ dogs

[leon]

just had a look and the older 80,s have a wastegate but the 120 dosnt    the 120 dosnt have a "dump  vaule " must be sutch a low pressure turbo its not needed ...my vito merc van has one   i'll look in to it see if it would be of any use on a LC  

It would fit between the turbo and the  intercooler
_________________
Should I have these bit's left over ?
1998 V8 LC Amazon VX work in progress
2008 pug boy
2009 pug boy
2010 pug girl
         ^ dogs

[leon]

got a reply on the dump vaule from one of the big turbo company's

[nick j]

Leon,
Thanks for the comprehensive response
Nick

[leon]