Gtr Boost Theories

[GENETIK]

ok i know theres topics on max boost on stock gtr turbos @ 1bar (14 psi) etc etc. and i havnt run any higher according to boost gauge in car.

but my theory is that the 2 turbos running COMBINED are making the boost thats read into engine @ 14psi.

So wouldnt this be split by the 2 turbos making half the boost each into the engine @ 14psi = 7psi each turbo?

if this is correct the rb26 engine could run on these turbos total into engine of 18-20 psi (technically) making the turbos run 9-10psi each if this theory is correct!

if anyone agrees of disagrees with this feedback appreciated.

(i am steel wheeling the gtr turbos anyway but was thinking on this theory anyways if its correct.)

feedback appreciated.

[blind_elk]

The inlet tract - from turbos to throttle body - is a single unit. Pressure created within the tract is distributed equally through the tract (as per standard laws of physics and fluid dynamics). So the boost created within the tract cannot exceed the boost created by the lowest boosting turbo.

[Moodles2]

In short, it doesn't work like that. If each turbo only made 7 psi, then the manifold would only see 7 psi. 7psi + 7psi = 7psi.

Flow is different from pressure, PSI is not a measure of how much air the engine is receiving.

Stock turbos make about 200kw as a pair at 1 bar (14.7psi), whereas the biggest twin turbo you can get GT2860R-10 as a pair at 1 bar probably makes 300-350kw (maybe more) only because it flows more air at the same pressure.

Picture this, what happens when your car's tyres are pumped to 15psi, and you want them pumped up to 30psi.. you set the air compressor to 15psi.. wait, what's going on my tyres aren't pumping up, they're still 15psi! Ever noticed as a kid when pumping up your bike tyres, when the tube is completely empty and it's real easy to get air in with the hand pump, but when it's inflated it starts getting harder and harder to put more air in.

[Galois]

Moodles is exactly right.

Each turbo is putting out 14psi, but having 2 turbos instead of 1 means that each turbo has to move half as much air to achieve the same pressure. That's the advantage of win turbo, you don't have to work the turbos as hard to get the same pressure, which means they can handle more pressure or they're more reliable. That's the theory anyways, not sure about the actual turbos used.

[snozzle]

i tried to explain this to a friend but failed, now i know how to word it for next time haha

[DVS JEZ]

has been tried and tested over and over and over and over,

people thinking the stock GTR turbo's can take more than 14psi, then boom shatter the ceramic turbo and kill a motor,

then people asking oh wait maybe if i run over 1 bar it wont happen to me

[R31Nismoid]

has been tried and tested over and over and over and over,

people thinking the stock GTR turbo's can take more than 14psi, then boom shatter the ceramic turbo and kill a motor,

then people asking oh wait maybe if i run over 1 bar it wont happen to me

Couldnt have said it better myself.

[GENETIK]

ok thanks for the responses guys!

i am upgrading the turbos to steel wheels n1 internals, then planning to up boost. any ideas on what max i could run into engine standard internals everything etc except air pods n exhaust etc.

?

[nuclear_skyline]

"i am upgrading the turbos to steel wheels n1 internals, then planning to up boost. any ideas on what max i could run into engine standard internals everything etc except air pods n exhaust etc."

Steel wheeled turbos are known to be good for 30 odd psi - give it a try and let me know how u go as I hear it sounds pretty good

[R31Nismoid]

ok thanks for the responses guys!

i am upgrading the turbos to steel wheels n1 internals, then planning to up boost. any ideas on what max i could run into engine standard internals everything etc except air pods n exhaust etc.

?

What upgrade turbos without ECU?

1bar is about the limit, same power as everyone else - 250rwkw give/take.

Cheap and nasty upgrade either way. Guess thats gonna happen more and more as GTR's come down in price.

[BoostdR]

There isn't anymore power to be made upping the boost beyond 1.1bar. The compressor is out of its efficiency zone after 16psi.. The extra boost and associated wheel speed doesn't make anymore flow.....just heat and the extra wheel speed is what takes your reliability away. At 120,000rpm the torque transfer from the ceramic turbine to the compressor becomes enough to break the ceramic/shaft fusion.

Matt

[R31Nismoid]

^ N1's are not ceramic

The N1's will make 280-300rwkw, more if they are the larger version (they are not being discussed here though).

You need a ECU (Eg. PowerFC) to make use of this however.

[MasterShake]

I always thought that since each turbo is only connected to 3 cylinders each that meant both were out putting 14 psi or what ever they are restricted to.

Edited September 30, 2010 by MasterShake

[blind_elk]

Both turbos are outputting to all 6 cylinders, because the inlet plenum spans all 6 inlet ports. They are each driven by 3 cylinders, which makes it easier to spool up to their maximum boost.

[DVS JEZ]

^ N1's are not ceramic

The N1's will make 280-300rwkw, more if they are the larger version (they are not being discussed here though).

You need a ECU (Eg. PowerFC) to make use of this however.

yep ^^^ I made 285KW on my GTR last week, steel wheels and power fc 18psi 600 tomei on a mainline

and last night i tuned a mates car and made 300.2kw on 19psi steel wheels power fc and poncams stock injectors on a mainline

[GENETIK]

Thanks for the feedback im yet to steel wheel the turbos but will need upgraded fuel pump/ bigger injectors/ upgraded ecu or remap n afm's etc, so more to do before the turbs!