Forum » General Tuning Discussion » RB - fitting 26 ITB's Link G4 retune

RB - fitting 26 ITB's Link G4 retune

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Hi team

I'm about to fit an RB26 ITB intake to my RB25. I currently run a Link G4 which is tuned with the base table of MAP/RPM.

What is the best way for me to fit the hardware, and adjust what I need to on the G4 so that I can drive the car to the dyno.

Once on the dyno I will get the tuner to tune with base fuel table as TPS/RPM and use 4D for MAP.

Thanks in advance

the bolt pattern of the 25 and 26 is different so you'll need some kind of adapter fabricated up, this would likely cost more than buying a Greddy copy manifold.

Do you run a wide band sensor already?

There's no quick and easy way to convert between a MAP based load input and a 4D system using TPS and MAP. Depending how far you need to drive and exactly how bad the low end AFR ends up being, I'd be inclined to leave the existing map in the ECU and retain the MAP load axis until it can be tuned. Don't expect great results and you may still need to make some broad adjustments to get the cruise mixtures acceptable but this should be adequate to nurse the car to a dyno provided you don't need to travel 500 km.

Great. It is about 50km I need to drive.

My rb25 is the early one from an r32 which doesn't have vct, so an greddy one doesn't fit.

I have an adapter plate to make the Rb26 intake fit to my head.