Dual wastegate, advantage and disadvantage

[MDK87]

Yeah that's the thing, it's a complete assembly.
I'm still not sure if I believe it lol
How could you print perfect spheres for the ball bearings? Not to mention that all of the little components (bearing cage, races, shaft, wheels) require different material properties so it can't be 100% stainless else it'd wear out in 50km's.
It must be made in a totally different way that I'm use to thinking of 3D printing.
Bloody hell, money gets shit done eh... I want money lol

 

[4piknup]

Na, they print the turbine housing as a assembly, With its adjustable nozzle in place. He is showing you the flapper as he says it (also at 2:39). It must have seals fitted after.
My understanding is the turbine housing is like a corkscrew inside a snailshell.

They should do the same on the compressor side.

Did you notice the 2stroke style exhaust? All big tapered expansion chanbers. Cool.
Also no wastegates.

 

[4piknup]

Sorry wastegate is under the turbo. You can see the spout for it.

 

[khubner1]

Here's that thing I was talking about

www.suprastore.com/spquspva.html surely we could work something similar into our cars would Likly work with a custom mani using an external gate as the valve

 

[GeoKez]

I reckon the way forward is electric 'turbo chargers', or electric powered compressors. I've been fucking around with some bits and peices and nearly got to a point where im ready to chuck a prototype together. An electric motor driving the exhaust side of a turbo works well, but trying to get an rewound brushless motor spinning @ 100,000 rpm for any amount of time is hit and miss (fucking dangerous when they let go too!), but using a big brushless motor driving a (belt driven style) supercharger at 10,000 rpm is proving a much more reliable setup. A TPS and a really simple closed loop feedback system to control motor RPM (thus boost) and the torque of the modern brushless motors can spin the compressors up supa quick. Things like anti-lag and launch spooling would be a thing of the past, an overide button on the steering wheel could give you 8psi at idle. Quick charging LiPo batteries on fly is a fuckache thou. When you Perth guys see a big mushroom cloud appearing over Ocean Reef, you know is all gone bad.

 

[MDK87]

Here's that thing I was talking about

www.suprastore.com/spquspva.html surely we could work something similar into our cars would Likly work with a custom mani using an external gate as the valve

I like that! It's a great idea. A bit exxy though.

I reckon the way forward is electric 'turbo chargers', or electric powered compressors. I've been fucking around with some bits and peices and nearly got to a point where im ready to chuck a prototype together. An electric motor driving the exhaust side of a turbo works well, but trying to get an rewound brushless motor spinning @ 100,000 rpm for any amount of time is hit and miss (fucking dangerous when they let go too!), but using a big brushless motor driving a (belt driven style) supercharger at 10,000 rpm is proving a much more reliable setup. A TPS and a really simple closed loop feedback system to control motor RPM (thus boost) and the torque of the modern brushless motors can spin the compressors up supa quick. Things like anti-lag and launch spooling would be a thing of the past, an overide button on the steering wheel could give you 8psi at idle. Quick charging LiPo batteries on fly is a fuckache thou. When you Perth guys see a big mushroom cloud appearing over Ocean Reef, you know is all gone bad.

Haha!
Idk, I don't think you'll ever reach the efficiency level of a waste gas turbine with a geared electric motor. For the the rotor to withstand large back-pressures as it would see during gear shifts, you'd need a decent inertial load, weighing down the whole assy and there goes your button touch spool up.
Sounds like a fun project but there's never a free lunch.. Or whatever the saying is lol
I think the future of petrol turbochargers will see more R&D in dynamic compressor and turbine housings to improve efficiency over a wide RPM range.
Dynamic variable vane compressor housings seems like a a big ask but after seeing that Koeningsegg video, I guess the sky really is the limit!

 

[khubner1]

it can easily be replicated in a number of different ways that one is just a bolt on adapter for i think it's t3 framed turbos. you could easily build yourself a steampipe manifold with a similar feature built into it using an external wastegate as the block off flange for one of the scrolls would cost no more to build than a conventional dual external gate setup

 

[GeoKez]

Come on Mo! We have logic controllers to run bypass/bov units to deal with back pressure, same as gas driven turbines. Multi pole motor controllers are amazingly capable now days, only imagination or lack there of prevents things getting done. Super charger compressor design suit electric conversion much better due to direct drive options given the lower rpm. Direct drive brushless motors are a cheaper lunch than gas restrictions in the exhaust, it's just the need to have F1 style re-gen to keep the batteries full that's the Moët lunch. Won't let that stop me, just might explode me shed trying

 

[Rockabilly]

Ad a clutch & bypass over to the large free exhaust gas turbine before the shed blows up ;-)
Cheers

 

[dakiller]

I reckon the way forward is electric 'turbo chargers', or electric powered compressors. I've been fucking around with some bits and peices and nearly got to a point where im ready to chuck a prototype together. An electric motor driving the exhaust side of a turbo works well, but trying to get an rewound brushless motor spinning @ 100,000 rpm for any amount of time is hit and miss (fucking dangerous when they let go too!), but using a big brushless motor driving a (belt driven style) supercharger at 10,000 rpm is proving a much more reliable setup. A TPS and a really simple closed loop feedback system to control motor RPM (thus boost) and the torque of the modern brushless motors can spin the compressors up supa quick. Things like anti-lag and launch spooling would be a thing of the past, an overide button on the steering wheel could give you 8psi at idle. Quick charging LiPo batteries on fly is a fuckache thou. When you Perth guys see a big mushroom cloud appearing over Ocean Reef, you know is all gone bad.

Look into doing some some maths on what sort of power your electric motor will need to make to make the required boost and flow rate. Someone had the same idea on another forum and for shits and giggles I estimated that to get the equivalent of a 14b turbo running 1bar through a 4g63 would require around a 30hp motor.

 

[4piknup]

Look into doing some some maths on what sort of power your electric motor will need to make to make the required boost and flow rate. Someone had the same idea on another forum and for shits and giggles I estimated that to get the equivalent of a 14b turbo running 1bar through a 4g63 would require around a 30hp motor.

Doesnt suprise me, I can imagine that a vacuum cleaner in reverse wont cut it (1000w) nor a 1.5 hp squirrel cage evap aircon fan either.
But you suggest 20 vacuum cleaners might be enough...

30hp... thats like a industrial diesel trailer mounted compressor... thats a lot of air

 

[GeoKez]

30hp is up there, I'm working on needing about half of that. I have 7.5kW to play with at this stage, can get a 11.5kW needing about 40v. Hang glider pilots are leading the way with big electric setups, they use them as sustainer motors. I'm more curious how much difference 10psi in an effectively NA engine setup will go.

 

[MDK87]

Although my opinion may seem negative on this subject, I think it's great that you're out there giving it a crack.
Some of us are a little more innovative than others and I'm definitely not one of those so I'll criticise your design all day long but I wouldn't be able to come up with anything better myself :lol:

 

[dakiller]

Doesnt suprise me, I can imagine that a vacuum cleaner in reverse wont cut it (1000w) nor a 1.5 hp squirrel cage evap aircon fan either.
But you suggest 20 vacuum cleaners might be enough...

30hp... thats like a industrial diesel trailer mounted compressor... thats a lot of air

Engines are essentially air pumps that have a bit of gas squirted in them. It is around 1.5CFM per HP out of a motor. So even just a 200HP engine needs 130CFM of air, I know my good shop air compressor is only 13CFM, what can a big diesel compressor do?

Turbos are absolutely awesome at compressing air, there is a good reason that nothing has replaced them in nearly 100 years

 

[4piknup]

http://www.kennards.com.au/index.php?fuseaction=product.view&productid=34

This is 130cfm at 100psi. So its overkill.

I dunno what the shop compressor cfm/pressure rating is. If they are 13cfm at 100psi, then maybe it will do 130cfm at 10psi. (They wouldnt be 100psi rating, must be 40psi or something like that. Or more likely 13cfm at 0psi)

 

[4piknup]

Very interesting geo. Give it a go.

 

[khubner1]

i wouldn't suspect you need alot of torque in one of these low pressure compressor setups. i'd me more inclined to try and drive a centrifugal supercharger with a electric motor they're desgned to start making 5 or so psi at 3k rpm and increase cfm as revs rise boost is only a measure of restriction so driving a centrifugal supercharger at say 10k rpm electric motor speed should provide enough cfm to maintain boost up to 10k rpm engine speed no? assuming the supercharger is cfm rated to make the hp the engine will make.

 

[Rockabilly]

DC instant up to 5000 max. AC works later, but revs to 10,000+
Needs a Curtis controller etc as the variable potentiometer.
Maybe 2x bovs to stop the TB shaft from bending.

But if it's elec clutched off boost, the N/A can suck past the free
spinning blades better than the slowing down shaft fixed to the motor.

Cheers

 

[GeoKez]

Centrif is really the only option K, for all the reasons you said, 100k+rpm is too much for electric. Depending on the spool time with the electric, I would hope that you could have 8psi at 1500 rpm.

@ Rockabilly - It will have its own brain, arduino controller reading tps and map amongst other stuff, have a young fella doing his fancy programming shit and this will compute a pwm signal to send to a brushless motor controller, and not sure on clutching. BOV should operate as per a normal system (read 'should'). The speed controllers don't have to wind down, they can go instant 'free wheel' which is effectively a clutch, or you can electronically brake them but I figure back pressure will take care of that. Most likely will aim to 'idle' the compressor when it's not pumping, just enough to maintain a good vacuum for brake booster (or bend throttle butterflies), but doesn't have to start from dead when needed. Amongst many hurdles, the motor to compressor coupling is a ball ache. Will most likely have a separate w2a cooling system for the electric motor too, bitch will get hot.

I did say it was 'the way forward', I never said it was the best way forward! May work, may not. You only live once, so fuck it, you may as well blown shit up and break a lot of things on you're way through!

 

[GeoKez]

God dammit! F1 beat me too it again.

Found this while browsing. It's a MGU-H from F1, but it shows that electric driven turbos are coming, it's just that F1 still want the hot side to for regen.