Turbos

GT PRO S Turbine

The HKS GPROS is a great turbo upgrade for the nissan skyline R33 GTS25-T (RB25DET) and the R34 GT-T (RB25DET neo). This turbo gives a great compromise between response and outright power, 270rwkw to 300rwkw can be expected with this turbo, some have seen 300+rwkw. This turbo produces more power than the GT-RS but sacrifices a little bit of responce This is probably as big a turbo as you would want to go with a standard internal RB25DET.

MODEL	Attachment control equipment	Correspondence output (PS)
GT2835Pro	Stronger Actuator	420
	Compressor wheel
Trim	Entrance diameter (mm)	Major diameter (mm)
56	53.1	71.1
	Compressor housing
Entrance diameter (mm)	Exit diameter (mm)	A/R
Exclusive use	Exclusive use	0.50
	Turbine wheel
Trim	Major diameter (mm)	Exit diameter (mm)
84	56.5	51.8
	Exhaust housing
Entrance flange	Exit flange	A/R
GT25 S/V	GT25 exclusive use	0.68

Garrett equivilents for GTR twin turbo upgrade

Garrett turbos are usually a cheaper option than HKS but keep in mind the cost of bolts, gaskets, and lines when comparing the costs.

HKS GTSS -GT2860-9
HKS 2530 - GT2860-5
HKS GT-RS - GT2860-10
R34 GTR N1 - GT2860-7

GCG Highflow Turbine

A company in Australian named GCG can upgrade you standard nissan skyline RB20/RB25 turbo.The upgrade includes, replacement of the ball bearing pack, larger steel turbine and Compressor wheels. The compressor and turbine hosing are hiflowed to fit the larger wheels. This turbocharger bolts directly back on the manifold with no modifications required, and uses the factory oil and water lines. GCG rate there Turbocharger at 450hp which seems about right. On a RB25DET you can expect power levels upto 265rwkw with cams. It is posible to replace the exhaust housing with a larger exhaust one from either a VL turbo or an old single turboed 300zx up to 290kw has been acheived with this setup.