Turbo cross section pics/idiots guide to turbos

[mintyfresh]

I'm doing a unit in work at the moment which includes aircraft pneumatic air systems and one of the methods they use for cooling bleed air from the engines is a turbo compressor. It's basically a turbo that the hot air turns and the energy that is transferred into the turning motion of the turbo results in the air becoming colder which they then feed off to various different pneumatic systems. Anyway, we got to look at a cross-section of a turbo from a DAF truck (my college is also a DAF training college) and it was pretty cool to see the inner workings (these turbos spin at 100,000rpm!) so i thought i'd take some pics to share here with a very basic explanation of how they work (PLEASE correct me if im wrong on anything!)

http://www.flickr.com/photos/47034206@N07/5576906747/

http://www.flickr.com/photos/47034206@N07/5576907385/

Pic from the net which is pretty good for showing the turbo setup on a Civic engine..

http://www.flickr.com/photos/47034206@N07/5577525186/

The turbine in the turbo (on the right in the top pics) gets rotated by exhaust gases off the manifold, which in turn drives a shaft connected to a compressor. The compressor side (left in the top pics) sucks air in and compresses it, then sends it out of the tubo, through an intercooler - in which the charged air gets cooled by cold ram air (air flow generated through the forward motion of the car) and then into the air intake of the engine. I'm sure somone here can explain blow-off valves as i dont know anything about these other than they make that trademark turbo PSSSHHT sound and are something to do with regulating the air pressure.

Feel free to correct me/go into more detail/explain more complex components i havent as im still learning!

 

[Stani1029]

Blow off valves just release the pressure from the pipes when the butterfly closes correct me if im wrong lol alot of pressure if you put your head over it :laugh:

 

[Baz]

Blow off valves just release the pressure from the pipes when the butterfly closes correct me if im wrong lol alot of pressure if you put your head over it :laugh:

Yeah thats right, basically a relief valve, nothing to do with regulating air pressure

 

[Ian]

A turbo is a simple device really. I've learned a lot about turbo's and engines over the past 4 years with various turbo cars that I have owned.

 

[joshbl]

I've done a lot on turbos at college. Dismantled a few too :grinning:

 

[Alexx117]

Blow off valves just release the pressure from the pipes when the butterfly closes correct me if im wrong lol alot of pressure if you put your head over it :laugh:

And to stop the pressure build up slowing the turbo down by pushing the opposite way which if I'm correct should reduce lag?

 

[Ian]

Indeed Alexx, since the pressure isnt bouncing off the butterfly and trying to stall the compressor wheel.

 

[NeX]

thats what a recirculation valve does, it takes air from in front of the turbo and puts it in the back so the turbo can freewheel without resistance, its supposed to keep the turbo up to speed while you change gear,

 

[mckenziecz]

thats what a recirculation valve does, it takes air from in front of the turbo and puts it in the back so the turbo can freewheel without resistance, its supposed to keep the turbo up to speed while you change gear,

same thing but the recirculation setup is million times better for the engine

 

[Baz]

thats what a recirculation valve does, it takes air from in front of the turbo and puts it in the back so the turbo can freewheel without resistance, its supposed to keep the turbo up to speed while you change gear,

In the back of what? Also I find a blow off worse for quick gear charges in the mach so it doesnt work on all cars

a recirculating valve is the same as a atmosheric Blow off valve only it recirculates it back into the turbo intake ,so the pressure built up in the boost pipes is released when you lift off the throttle