No reason in the world it WONT work or CANT be done but as Anton suggests, unlikely with just a balance tube on the outlet of each turbo. Cmon guys, it isnt hard to bring the exhaust gas fome one side to the other on a V motor: Like this: To this: Now, where you get to mount your 2 turbos is anybodies guess but its perectly doable and technically sound. Whether its worth the hassle or not, well thats going to be a result of a lot of a shiteload work. L8r E
There was only a few hundred real 959's made to get around the racing homologation rules. Apparently for group B rally :drool:
I did a rough drawning for the VG30dett setup: I'm not sure if this setup would make any sense. Or any reasons why this should not work? I believe the only difference between the Supra and the Porches engine is that Turbo B come on action from 0 RPM and producing 0 boost. So you are going to get a flat spot at where Turbo B spool to 1psi. where in my setup. Turbo B is launched at 15000RPM with 3psi loaded. So I guess it should not have plate spot.
I reckon this could work, but I think everyone is remaining focussed on the twin throttle body set up. I see no reason a custom manifold couldn't be used, with both turbos feeding a single large throttle body, that way balance pipes become a non issue. Some sort od valve or pressuer system would probably be needed to cut out the smaller turbo as the larger turbo kicks in to eliminate boost leak back through the smaller turbo.
It unbalances the Workings of the Engine spinning two different spooling Turbos. It will work for sure but it is not EVER going to be balanced unless all of the Exhaust gasses go into one Manifold and then the two turbos hang off of the same manifold. Yes it will work but very inefficiently.
tuning nightmare, you would really have to run it as 2 3cyl engines because the exhuast gases are not common to both turbo's so one will have huge backpressure and EGT's compared to the other side, but by the same token the balance tube is forcing the same amount of air into both engines. I think it could be easier and more cost effective to twincharge it, assuming theres enough room, using a butterfly valve to divert the intake charge between the S/C and turbo. A clutch would be used on the S/C to turn it on/off. Huge amount of work just to avoid lag though. With that much torque down low traction could become an issue, sometimes a bit of lag and boost threshold isn't a bad thing
How do the factory sequential turbo set ups get around the different back pressure on different size turbo's? I imagine that this would be an issue even on a straigt six (eg, cyl 1-3 on 1 turbo, cyl 4-6 on another turbo). Maybe he could hang both turbos off a common "log" style exhaust manifold running across the front of the engine, into a common intercooler, and back through a single throttle body. A lot of plumbing, but could probably be done with a bit of mucking around.
by sharing the exhaust gases the factory systems see roughly the same backpressure on all cyls, the exhaust gases that pump into the smaller turbo at lower revs are switched to the bigger turbo at higher loads
So maybe the "log style common manifold could work, utilising valves or whatever to change the "working" turbo over at the appropraite rev range. A lot of work, but I say give it a try if you have the time/money and are curious. I guess a simpler option would be to plumb up one big turbo to both cylinder banks. Same sort of result, low down boost as all cylinders pushing the turbo, with more high up boost due to turbo size.
Balancing the exhaust back pressure (created by the different turbos) would be difficult with that set up.
I am not sure if I am reading your picture properly but is turbo A providing the air for the whole 3.0L displacement until turbo B makes 3psi? If so would turbo A be able to flow enough air to give you good low down response while you are waiting for the valve to open and let the air from turbo B come in?
