View Full Version : How do turbo's work?
OK. I've found a site that shows a fairly good diagram.
http://www.turbotechnics.com/turbo/turbowork.htm
But what I am trying to work out is 'how to DIY'
Basically this is how I figure it works
Exhaust gasses spin up the turbo on the way out to poluting the world.
This spins a rotor that sucks air in from the airbox. then thru a cooler as the turbo is 'hot'.
this then goes into the inlet which adds the petrol.
Where does the DV fit into this (and the wastegate)
am I being dumb, but it seems pretty simple.
Mark
wanderer
04-11-2002, 18:57
Mark,
This link (http://www.howstuffworks.com/turbo.htm) might shed a little more light on things.
The Howstuffworks site is full of useful infro on loads of things.
wastegate is a valve which opens depending on the strength of a spring (actuator). this stops the turbo spining out of control and boosing your engine away. the DV reciculates the boost in the inlet system. this stops the boost going back through the turbo the opposite way and stops wastegate chatter
ibizacupra
04-11-2002, 22:47
Originally posted by vibrio
wastegate is a valve which opens depending on the strength of a spring (actuator). this stops the turbo spining out of control and boosing your engine away. the DV reciculates the boost in the inlet system. this stops the boost going back through the turbo the opposite way and stops wastegate chatter
How does a DV stop wastegate chatter? It vents to either atmo or recirc for the inlet system. Its purpose is to prevent compressor stall. Strange really as the K03 is small it might not worry about back surge on gear changing. (my old Renault turbo did'nt with its T2)
Bill
ibizacupra
04-11-2002, 22:49
Originally posted by MarkP
OK. I've found a site that shows a fairly good diagram.
http://www.turbotechnics.com/turbo/turbowork.htm
But what I am trying to work out is 'how to DIY'
Basically this is how I figure it works
Exhaust gasses spin up the turbo on the way out to poluting the world.
This spins a rotor that sucks air in from the airbox. then thru a cooler as the turbo is 'hot'.
this then goes into the inlet which adds the petrol.
Where does the DV fit into this (and the wastegate)
am I being dumb, but it seems pretty simple.
Mark
Mark.
A really good book on this is by Corky Bell, called Maximum Boost
I got mine form Amazon.
Very informative.
regards
Bill
hopkinsgm
04-11-2002, 22:54
Originally posted by MarkP
...am I being dumb, but it seems pretty simple...
As with so many things, the principles are simple, but making it work correctly and controlling the system is where it all starts getting a bit tricky. The article you posted makes a fairly major assumption - more air = more power. Not strictly true. More air only means more power because you can burn more fuel. But obviously, only if you can supply the fuel... And if the inlet charge (or exhaust gasses for that matter) are stalled by cr@ppy head castings and small valves, you have problems.
Not that it has much to do specifically with turbos but clearly there will always be a trade-off between volume and flowrate, and you can't make that one work out unless the size of the inlet varies with rpm. VTEC's (etc) address this to an extent by extending the valve durations at high rpm, although I still reckon that a far more elegant solution would be to build a hybrid 8v/16v motor which brought in the second bank of inlet and exhaust valves in at high rpm. If Porsche can experiment with hybrid 4cyl/V8 motors (this was years back btw), then why not...?
G
MARK - dont forget compression ratio is usually lower on a turbo motor to compensate
ahh sod it -weld it on and tape the pipes up til it goes like stink LOL
ooops sorry thats an LPG conversion :)
I must admit it's a tempting thought, I am just wondering if my ECU is stupid enough not to care - ie just pump more fuel in
M
hopkinsgm
05-11-2002, 00:05
Originally posted by flapper
...ahh sod it -weld it on and tape the pipes up til it goes like stink LOL...
Or just bung an extra cylinder head gasket in - it's a bit safer as you blow gaskets out before you really hurt anything, but it really is a bodge worthy only of S@xo's and Nov@'s...
G
hopkinsgm
05-11-2002, 00:06
Originally posted by MarkP
...I am just wondering if my ECU is stupid enough not to care...
Injectors up to it? How about your fuel pump? etc...
G
Originally posted by ibizacupra
How does a DV stop wastegate chatter? It vents to either atmo or recirc for the inlet system. Its purpose is to prevent compressor stall. Strange really as the K03 is small it might not worry about back surge on gear changing. (my old Renault turbo did'nt with its T2)
Bill
well with vacum hose inplace DV works no chatter. take off vacum hose DV don;t work chatter. does it on mine
Originally posted by vibrio
well with vacum hose inplace DV works no chatter.
....and the next question is......what is wastegate chatter?
Cheers
ibizacupra
05-11-2002, 17:08
Originally posted by djawol
....and the next question is......what is wastegate chatter?
Cheers Remember the Grp A Cossies in Touring cars? *(ahh those were the days :p)*
the flutter noise they made on gearchange?
thats the sound.
Better than the wooshy crap RS's and the like make IMHO
Bill
is that where we talk about it?
Dormouse
05-11-2002, 17:41
I though my jokes were bad (and they are)..but that....well...
LOL
Dor
Dormouse
05-11-2002, 17:41
BTW Glyn / Bill...what time is GTi on Wednesday?
Cheers
dor.
Originally posted by Dormouse
BTW Glyn / Bill...what time is GTi on Wednesday?
Cheers
dor.
8pm
I'll be there too :D
Dormouse
06-11-2002, 13:33
Cheers M8. See ya there.
Dor.
Originally posted by ibizacupra
Remember the Grp A Cossies in Touring cars? *(ahh those were the days :p)*
the flutter noise they made on gearchange? thats the sound. Better than the wooshy crap RS's and the like make IMHO
Bill
Ahh, I just love that sound. It's so addictive. It was similar on my Uno Turbo, just A LOT quieter. It's been too long since I last went out in a Cossie. That said, there's absolutely loads in Peterborough. Something to do with Specialist Car Services I guess. :D
Don't like release-to-atmosphere dump valves. If anyone reckons they're getting much power gains in reality, I think they ought to try it out on a dyno. Most of it is in yer head. In fact, I've seen RS Turbos and Cossies go much quicker when they're taken off. Too dangerous not to run an atmos-DV with big boost though, say over 1.5bar.
Anyways, what kind of sound do ya get with Leon Cupras? Only I'm thinking about getting one next year.