Modified -9 Turbo, What Would This Behave Like?

[No Crust Racing]

Been offered some turbos, very close to -9 specs. This will be a on a 34.

-9 are as below and this reads comp to turbine.

Garrett 707160-9 44.46 - 59.41 56T 0.42 42.4 - 53.85 62T 0.64

But what I was offered has 60mm comp wheel and a 53mm turbine wheel.

Bigger comp wheel would normally mean more power, but in the same size housing will that mean more response and more power or more response and less top end as it will choke out.

Likewise, the slightly smaller turbine wheel tells me a little less response, but flow better top end in the same housing.

Any guesses on what the characteristics will be?

Edited November 12, 2015 by ActionDan

[No Crust Racing]

Was suggested to use my R34 .53 front housing instead to avoid working the turbo as hard up top.

Any input?

[GTSBoy]

My guess is that unless the blade design of both is identical then the aerodynamic differences of each wheel could be more significant than those tiny diameter differences. Also, no mention made of the minor diameters of the other wheels.....mileage may vary there too.

If aero design was otherwise the same, then I'd say that your impressions are pretty close to correct and it might take a very sensitive bum dyno to feel the difference.

[No Crust Racing]

That I can't comment on.

All I know is it will essentially be a 2560R core (and turbine wheel) with a .64 rear housing and a -5 comp wheel in my .53 Comp housing.

To me that all equates to a more responsive -5 but will less top end?

[Dose Pipe Sutututu]

my input and thoughts, feel free to ignore

Get those turbos, sell them.. then convert to a single GTX3576 or even GTX3582 on a proper twin scroll manifold and a proper divided housing with either twin gates or merge both pulses all the way to a single 50mm gate or larger. Eventually all response and power hungry GT-R owners convert to a modern single turbo.

[No Crust Racing]

Get pulled over, get defected into oblivion.

I will have the only R34 in town and it will look like a Z tune kinda, I am gonna get pulled over...

Thanks but no

[Roy]

Sounds like a winner...worth a try as on paper seems an interesting combo. Who does it? Its your street car so doesnt really matter if its out by 100-200rpm and 10-20rwkws...still be ball achingly fast for a street car

[R31Nismoid]

Did you talk to Chris like I told ya Dan?

He'd be able to let you know if it was a good idea or not.

[No Crust Racing]

Getting onto Chris is next to impossible given his workload and how often they answer the phones.

I found a good value -9 kit so bought that.

[R31Nismoid]

Hence I use email lol.

[No Crust Racing]

Same result, hence I was trying the phone.

I also tried FB messenger for Chris personally as we're still connected from DECA days.

All sorted now, turbos will be here today or tomorrow, tuner will supply the Haltech.