The R34 GTT standard intercooler arrived yesterday, as you can see from the pictures it is in almost brand new condition;



The comparisons with the standard Stagea intercooler follow, note the extra thickness and the 3 extra rows (height)




Time to measure it up, the core is 80 mm thick, compared to the standard Stagea's 65 mm. The core is 210mm wide and 225mm high (18 rows) while the standard Stagea intercooler is 210mmmm by 185mm (15 rows). This would indicate an improvement in flow of 23%, R34GTT is 206kw and Stagea is 170kw, that's a 21% improvement in power. Seems logical that Nissan would have some mathematical basis for upsizing the intercooler

The first job is the to clean out the inside, there is always some oil film in there, regardless of how new the engine is. I will be using the usual 50/50 kero and metho mix, slosh it around and empty out. Keep doing that until it comes out clean. Then flush with hot water and leave in the sun to dry out. This is what the first flush of kero/metho looked like;



And remember that's out of an R34GTT with ~30K's on it. What do you reckon the inside of your intercooler looks like?

The standard Stage mounting brackets bolt straight up to the R34GTT intercooler, as per the following picture. As do the intercooler pipes, absolutely no modifications were required;



To further improve the cooling, I want to have most of the air that goes through the LHS bumper vent go though the intercooler. Standard, around 30% of the air that goes though the vent, is ducted through the intercooler. This is the standard Stagea plastic ducting bolted onto the R34GTT intercooler. As you can see I had to redrill 1 of the three holes (RHS) and make up a spacer (strip of aluminium) for the third (top LHS).



If you look at the above picture you can see where bugs have come in through the vent in the bumper and hit the plastic above the standard duct. This was a good hint on how to configure a larger vent. Notice how the standard Stagea plastic ducting is a bit short for the extra height of the R34GTT intercooler. The new piece of ducting also has to fix that.

So the next job is to take the standard Stagea plastic intercooler ducting and add some aluminium to it to expand its dimensions to those closure to the vent. I cut a piece of alumium sheet to the right dimensions and bolted (3 X 6 mm bolts and nuts) it to the top of the ducting. Then I cut a triangular hole in the standard plastic ducting to enable the airflow trapped by the additional ducting to flow though the core.



Then it is time to fit the R34GTT intercooler and ducting into the Stagea. Since the pipework is the same as the standard cooler this is a pretty simple job, no cutting or modification required. I did the install from underneath, with the front bumper in place, this made it easier for me to measure up the ducting.

The next step is to give it a run up on the 4wd dyno and see what sort of results we get. I am anticipating a 25 to 30 rwkw increase from the intercooler and the exhaust upgrade. This is a bit more than you would expect from the parts alone, as I believe I can increase the boost with the IEBC by 0.1 bar and lean of the mixtures with the DFA to a more power friendly 12 to 1. Neither of which I can do at the moment because the standard Stagea ECU is a bit too smart. Removing the restrictions, particularly the exhaust, should mean I don't have to wind in as much correction.

Hope you will enjoy reading about this as much as I will actually doing it.


PS; this is a live post and will be updated as we go along, pictures and all.