Throttle plates and compressor surge

[monsterer]

I don't get what the issue is, you press the throttle, turbo spools up till it reaches max pressure (decided by the wastegate) you back off the throttle, engine speed decreases, turbo slows down. You can keep the turbo spinning a little longer to avoid lag by fitting a BOV, but it doesn't make a lot of difference on a diesel engine.

Its just physics. What are you trying to achieve?

Ok, here is a decent definition of compressor surge:

COMPRESSOR SURGE - Compressor surge occurs when the throttle is slammed shut and air is caught between a pumping turbo and the throttle plate. This air blasts its way backward out the front of the turbo. When this happens, there is suddenly room for more air in the manifold, and air is pumped back in by the still-spinning turbo. The throttle is still closed, so the air again blasts back out through the turbo. This continues until the turbo loses enough speed for leak back around the compressor to dampen the air oscillations. Compressor surge can also occur under boost if too much boost pressure is present with low airflow through the system. The chirping sound heard from the turbo when lifting off the throttle while operating under boost results from this oscillating air volume. This noise is suppressed by the bypass valve.

You should hear this noise on any turbocharged car with no dump-valve and a thottle, so i don't understand why i don't hear it on my surf...

I'm just curious, is all.

Ta, Paul.

[monsterer]

Reading this thread and your previous posts, it seems to me that you're unhappy with the way your 3.0 turbo diesel engine performs, be it sound, power output or engine aesthetics. As long as it's running O.K. and no leaks or smoke, looks good parked on your driveway and gets admiring glances from inferior 4x4 owners, then whats the problem? If you want M.A.F. sensors and M.A.P, sensors and dump valves and wastegate chatter, then you should have bought a W.R.C. Evo or Scooby!

You've obviously done your research on all things diesel and petrol turbos, and know what they should and shouldn't 'do', but the Toyota 3.0 4Runner is what it is, a handsome looking 4X4 with a turbo diesel engine and a throttle body, which, for some reason you think doesn't need to be there. Take it off and see how the engine runs if you like.
Sheesh!!

Strange that you think i want to change anything about the engine i have. All i'm trying to do is learn as much about it as i can.

Ta, Paul.

[BUSHWHACKER]

Strange that you think i want to change anything about the engine i have. All i'm trying to do is learn as much about it as i can.

Ta, Paul.

K.

[TonyN]

Ok, here is a decent definition of compressor surge:



You should hear this noise on any turbocharged car with no dump-valve and a thottle, so i don't understand why i don't hear it on my surf...

I'm just curious, is all.

Ta, Paul.

I doubt the engine revs high enough, or produces enough boost for it to be an issue.

Compressor surge is a fault, you shouldn't really be hearing it on a well designed system.

[BUSHWHACKER]

I doubt the engine revs high enough, or produces enough boost for it to be an issue.

Compressor surge is a fault, you shouldn't really be hearing it on a well designed system.

Quite. Diesel rarely rev to more than 5000rpm so turbo stall is never an issue.

[Chillitt]

wheres nev.? he has ditched his butterfly...

[TonyN]

wheres nev.? he has ditched his butterfly...

That was only the shut down valve, not the the throttle flap!

[BUSHWHACKER]

Simon O.

[Chillitt]

ok wrong person, wrong bit... i'll get me coat.... did i mention i made some sloe gin this year?

[BUSHWHACKER]

ok wrong person, wrong bit... i'll get me coat.... did i mention i made some sloe gin this year?

Brilliant! got any left?

I had some sloe vodka a few years ago, could have drunk that all day.

[TonyN]

ok wrong person, wrong bit... i'll get me coat.... did i mention i made some sloe gin this year?

[Chillitt]

Brilliant! got any left?

I had some sloe vodka a few years ago, could have drunk that all day.

betcha couldn't.. its a bit ... rich....

[BUSHWHACKER]

betcha couldn't.. its a bit ... rich....

I know, t'was a bit like syrup at the bottom of the bottle.

[dirtydog]

Ok, here is a decent definition of compressor surge:



You should hear this noise on any turbocharged car with no dump-valve and a thottle, so i don't understand why i don't hear it on my surf...

I'm just curious, is all.

Ta, Paul.

i get it on my 2.4, well at least i get a TSHHHHH noise if i cane it then lift off. maybe ill record it one day.

[monsterer]

i get it on my 2.4, well at least i get a TSHHHHH noise if i cane it then lift off. maybe ill record it one day.

Do you have a dump-valve fitted or are you stock?