Black smoke?

[Budgie]

I always thought it was the exhaust gasses passing over the fins on the turbo's drive fan that drove it, hence the increase in boost pressure as the revs increase.  :?

[Xtremeteam]

Often oil in the turbo , a little normally get past the seal when its been stood. The reason why the turbo doesn' repond to the increase in fueling is that it isn' exhaust gas that makes it spin. THe turbo spins as a result of heat,thats why it lags more when the engine is clock cold.

NOPE:lol:

The turbo is driven by the exhaust gasses exiting the system,the reason you have lag is to get more go you need more in,to get more in you need more coming out to drive the turbo,thus thens spins it up & pushes more in,did a talk on this for a module at college but cant fiind anything that would be useful to abny 1 else

Basically the gasses coming out drive the turbo spinning it up & pushing more in

[Bulli]

:oops: Read below, perhaps they need a new module??Seems your colege stuff wasnt entirely accurate but then again neither was i. After speaking to a mate who has worked on F1 ans BSB he said as shown below that the spin up is a result of both gas volume and heat! heat being the Key ingredient.....as shown below from an american turbo theory site
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TURBO THEORY

 




The larger the compressor and the higher the pressure (boost) we want, the quicker the power from the exhaust turbine is used up. Put in a larger exhaust turbine and it will take the engine longer to develop enough hot expanding exhaust gas to spin it, slowing down the compressor and causing turbo lag. At this point I am going to repeat something stated earlier, do not think of a turbo charger as a bolt on piece of equipment, think of it as a system.

The turbine is powered by hot expanding exhaust gas, a lot of hot expanding exhaust gas, the more and the hotter the expanding exhaust gas the better. I am sure many of you have seen pictures of turbo charged engines with cherry red hot exhaust systems and turbo housings

[rollazuki]

Turbos spin due to gas expansion into manifold, and hence turbo!
Heat is the culprit which makes it spin, not any volume of gas.
A hot motor will suffer less turbo lag than a clock cold motor.
Heat expansion is the key!
to reduce turbo lag, use a turbo with a lower A/R ratio(clearance of rotor to housing it runs in)
or generally a smaller lighter turbo.
Top end performance will suffer then though.
Some form of dump valve(recirculating is even better) will keep turbine speed up, allowing the turbo to 'spool up' quicker.
Rollazuki :D

[muddyweb]

I think we are getting a little confused with our terminology here...

Yes... heat plays a big part in turbo operation because expanding gas creates gas flow, and gas flow turns the turbine.....


So... exhaust gas turns the turbine... by virtue of the fact that it is expanding and creating gas flow.... more heat creates faster gas flow and as such the lag effect is reduced.


Turbos don't operate on heat... they operate on gas flow.

[Bulli]

why then does the turbo spin up quicker when the engine is warm. The volume of exhast is the same if the engine has been running for 5 seconds or 3 days at the same rpm.
Anyone who had a td knows that they are sluggish as hell untill the engine is warm and it is nothing to do with oil viscosity before anyone throws that in.... :?:

[muddyweb]

So... exhaust gas turns the turbine... by virtue of the fact that it is expanding and creating gas flow.... more heat creates faster gas flow and as such the lag effect is reduced.

[muddyweb]

Not sure what the argument here is really...   the turbocharger uses a gas turbine to make it work.    All we seem to be discussing is how the heat build up affects the speed at which the turbine is propelled.

Boyle's Law, amongst other things, will explain why a hot gas through a fixed aperture creates more gas flow.

[rollazuki]

[-X

[Bulli]

I thought Boyles law was simply a way of calculating the volume of gas at a particular pressure - at a fixed temperature.
eg; p1v1=p2v2.
got nothing to do with expansion of gas as a result of heat.
Charles law deal with heat in gases , you mught be able to use the ideal gas law - PV = nRT
but i have no idea how..

[rollazuki]

Time out, If youre gonna start talking physics, Im on my way........ :?

[muddyweb]

You are absolutely right, and it was a bit of an abstract example... what I was getting at is that there is a relationship between the temperature of the gas and it's volume.. and hence its rate of flow through a given aperture.

Bear with me... it's been a few years since I did thermodynamics and I'm a bit rusty !    <potters off to brush up on adiabatic and isothermal theory>

[rollazuki]

Diabetic what.......
Its insulin you need..........
 :shock:

Lets just put turbocharger operation down to the black magic that makes the rest of the engine work, (bit like the smoke that is contained within wires)

As far as the widget goes that stops black smoke(isnt that where we began)  If it affects the EGR valve, all its doin is allowing the engine to breath 100% fresh air(not tainted with Re-burnt exh gasses) This will make the engine run cleaner and with more power, but allow the exhaust gas to build up NOX(oxides of nitrogen). Why bother, just put a blank over the egr and have done!!!!!!!!!!!!!!!!!!!!!!!
Rollazuki(seeking power in the face of emissions regulations!)

[gords]

This link will come in handy for explaining things if you want to play with the injector pump.  

Does this relate directly to a 300TDi, or is it for info/guidance only?

Is it worth doing these adjustments without upgrading the intercooler?

[Budgie]

Gords,
Although the site is for the Dodge Ram, the 200 & 300 TDi's use the same injection pump as the Ram so the alterations relate directly to them and they will work with the standard intercooler, although the amount of alteration required will be less. :D

Do a little adjustment at a time and test the results is the best way to go, and make a note of what you've done so you can put it back to standard if it doesn't work!! I would work on one thing at a time, start with the diaphram, then the smoke screw, then the star wheel. I've only played with these 3 as that was enough for me, it started smoking too much when I had a go with the screw on the back of the pump so I put it back to normal.

The one that's easiest to do is the diaphram, if you have the standard intercooler then turn the diaphram no more than 90 degrees and see what a difference it makes. If it smokes too much then turn it back a little.