have anyone have this set up ? with what result?

 

On a YB that sounds like it would surge its tits off, but ive never tried one personally.

 

sorry don't undestand surge....

 

turbo surge

technical article here about it

https://passionford.com/forum/showth...ighlight=surge

 

Brief explanation:
Surge is caused by stall, which is worsened by surge, its a vicious circle...

Imagine the way our turbocharger's compressor is driven, right back to basics: The turbine wheel is spun by exhaust gas, utilising also the energy stored in the exhaust gas as latent heat.

This force on the turbine shaft generates torque at the compressor end as they are physically connected. Remember that part as its the key element, Torque

Ok,
Now lets imagine our turbocharger compressing air, forcing it into the engine, the engine is utilising it.. what happens then? Ok, The engine expells it, and our turbine housing pressure goes up accordingly, the torque applied at the turbine wheel increases, increasing the spin speed and compressor efficiency at the other end. Great chain of events!
End Result? boost is climbing nicely.

Ok,
Now imagine this scenario:
The turbo begins to spin, as above, but the compressor wheel is generating more air than we can move and the torque required to spin that huge compressor is not being met? Remember that unless the air is processed by the engine, and expelled as hot, rapidly moving air into the turbine housing, our turbine shaft torque will not increase to spin the compressor faster, and it may well diminish.. our compressor is slowing, braked massively by the compressed air its trying to overcome and increase.....

Result? Compressor starts to slow a little.. (beginings of a compressor stall)

Ok,
So now what?
The engine is still rotating and consuming air, but the turbo has stopped producing an excess, so our engine has now had chance to consume what excess was available and the inlet pressure is now diminishing, the turbine torque is now increasing again...

VERY IMPORTANT:
Remember also that at same time, compressor resistance to spin has also dropped due to housing no longer being as pressurised and as a result, the torque required to spin it has dropped massively..

Boom.. Suddenly the Turbine wheels torque massively exceeds the compressors resistance and the turbo spins to speed in an instant!! Sounds great, rapid boost climb!! The compressors acceerating at over 2G

BUT:
We just hit the same problem again, our huge compressor has made so much boost, so fast, and is trying so hard to push the massive volume or air, that our YB cant use it.... so we start to slow again........

So we went: Fast, slow, fast, slow, or in other words: The turbo is Surging.
As you can imagine, it continues this cycle until it hits the revs your engine consumes all the air.. then your away!!

Downsides to this surge are pretty obvious:
We can have serious bearing wear, due to the excessive loads imparted on the shaft supports.

Compressors have been known to simply explode!!

Worst case scenario, the compressor being slowed rapidly with a turbine still trying to accelerate it can simply do as expected, part company.

Hope this helps to explain in as simple terms as i can put it, the phenomena known as "Turbo Surge."

 

the above is Stu's explanation, not mine

 

thanks! what can be done to eliminate surge on the YB ? but i thought gt turbo ia a popular turbo to use on the YB.

 

"A gt turbo" is kind of like saying "a car" its a very broad description.