Savington

iTrader: (31)

Very bad idea. Instead of surge, you would get overspeed.

RattleTrap

I thought that was a wastegate?

tasty danish

iTrader: (9)

Wastegates do under normal circumstances. In this case we have significant load on the compressor causing airflow through it to slow, thus skyrocketing the AoA on the compressor blades causing a surge/stall. Sav is suggesting that venting the pressure in the line would cause the compressor blades to accelerate since they would have a decreasing load. Kind of like accelerating your car then pressing the clutch in with the accelerator still floored.

Sav, I know the applications are apples to oranges, but in aviation we have relief valves that allow the intake charge to speed up, it has little effect on the speed of N1 (the blades) as they are maintaining rpm because they are being driven, though they are wanting to slow down due to the reversion. Allowing the intake to pass evens it out.

I'm not convinced this would create an overspeed.

triple88a

iTrader: (2)

I'm not talking a 3" hole.. i'm talking a small hole that closes at x rpm.

Wastegate is on the exhaust side, we're talking about intake side.

tasty danish

iTrader: (9)

Bingo. You basically just described the system I'm talking about. Nice job.

18psi

iTrader: (76)

bottom line: on our poorly flowing low displacement motors there isn't much you'd be able to do with 25psi out of a 600whp turbo at 2500 rpm.

So no matter how much the kiddies have wet dreams about "OMG SPOOL AT 1500 AND BOOST EVERYWHERE, it simply defies physics.

You want spool at 1500 get a 10L+ diesel.
You want power at redline get a honda.

You want a watered down compromise of both, get a miata

/thread

Boost Joose

Ha, ok for some reason I was thinking the the VGT was on the compressor side.....my mistake. But, why dont they do the VGT on the intake and exhaust sides? I know that would make it even more complex but at the same time make it that much better if operating properly.


Hmmm....actually I dont even know if it would help much if any at all. Thoughts?

Faeflora

iTrader: (2)

Well sure it would help. Having a variable blade compressor AND turbine would be sweet.

Why not also have a variable A/R housing too? FU YEAH

Boost Joose

Approaching overkill....the variable vanes act like a variable housing

18psi

iTrader: (76)

why not just have variable everything

lol

Faeflora

iTrader: (2)

Yeah variable exhaust for variable backpressure too!!!!

And variable IC for variable charge cooling!!!

And variable tire size for efficiency vs speed!!!! OMGZZZZ

triple88a

iTrader: (2)

The vanes dont work this way... That's why the they are not on the compressor. They direct the air flow at an angle, that's all they do. The closer to a right angle they are, the more the turbine is pushed, the more rpm can be achieved (with the amount of exhaust gas). That wouldn't do ---- but block flow on the compressor side.