Gcg Highflow On Rb25, How Much Boost?

[Rolls]

I've got a gcg highflow on a series 1 rb25det (rebuilt with forged pistons etc) how much boost should I be trying to pump out of this turbo? I've heard they are good for 18psi on a 25, will it make more power if I go higher? or is this the limit with the internal wastegate? Just going to be using a cheap bleed valve.

Also with stock cams where will the power start to drop off, I've had a look at the dyno thread but it is a bit hard to tell, I get the feeling around 7k though?

Cheers.

Edited September 30, 2009 by Rolls

[R31Nismoid]

Will it make more power? It's anyone's guess

just screw boost in until it stops making power/intake temps get too high etc.

Stock cams - never. I ran factory cams with a 600hp GT30, power held till redline (8000rpm) everytime

[andymoocow]

i have a GCG high flow on My series 2 R33, with all supporting mods injectors, PFC, Profec B Spec 2 boost controller etc etc and it runs 20psi and tapers off to 18psi higher in the rev range. Tuned by UNIGROUP engineering in Sydney, who did an amazing job, and the car drives with almost stock like response down low.

still stock CAMS as well. If that helps.

[Rolls]

Nice I had a look in the dyno thread and looks like people are pulling about 250rkw with that kind of boost starting to taper off at 7k. What power does yours make and where does it start to drop off ?

I agree it is a lovely turbo to be able to make that sort of power but still drive around like a stock rb25 in the low revs, soon as you get any boost it is much quicker.

Edited September 30, 2009 by Rolls

[andymoocow]

Pm sent dude.

[geraus]

yeh im running a hypergear highflow 17.5 psi to 233kws with leaks.. and supporting mods pfc,injectors ect...

[Rolls]

Is a hyper gear high flow anything at all like a gcg highflow though?

Pm sent dude.

Very nice dyno curve, I'm excited : D

Edited October 1, 2009 by Rolls

[R31Nismoid]

Is a hyper gear high flow anything at all like a gcg highflow though?

In most cases no

They are the bush bearing version, so half the price. Wheels could be different too, without specs of each hard to say

[shotter]

I asked gcg a few months ago what the max boost of the highflow is and they said 20psi. Currently im running 17psi.