Our last work on our project R35 GT-R was to do the suspension and brakes to bring them up to a high level and address some of the R35’s shortcomings in those departments. With our suspension and brakes now at supercar levels of performance, it was time to shift our focus to the engine. The VR38DETT engine found in the GT-R is an exceedingly easy engine to get power out of. However, the R35 is plagued by heat issues even in stock form. In our efforts to get balanced performance we will attack the issues of heat and work to get 620-630 whp using simple bolt-ons. At this point, we are close to the limit of the stock connecting rods and the driveline and we will have to go inside the engine and transmission to maintain reliability. Our end goal is 1000 whp which we feel is the GT-R’s sweet spot. At this power level, it is possible for the car to be bulletproof and have better than stock driveability. Our goal is to be able to drive to the track, run a high 9-second pass, then drive home in comfort in a car that can still lap a road course with a 200 mph top speed. Of course, this power level is chump change for the VR engine as some tuners are already more than doubling that power level but we want a fuss-free car that can give any exotic supercar grief. We think we can even get to supercar parity with bolt ons! Well, it’s on to step one, getting more bolt-on power with the folks at Greddy Performance Products, Cobb Tuning and Radium Engineering.
Having installed Greddy’s 94mm titanium exhaust in our last installment, we will be running Greddy’s 76.3mm dowpipes to really uncork our stock turbos on the track. For street use, we will run the stock downpipes. This will require two different tunes, one for racing on the track and one on the street and we will be taking advantage of the Cobb Acess Port to quickly switch between track and street tunes.
The Greddy downpipes have a bellmouth inlet that bolts up to the stock turbine housing. This is a nice and clean transition to the tubular part of the downpipe that will have minimal restriction. The Greddy downpipe has a nice thick cast flange for good fit and no warping. The bung for the front 02 sensor is also here where it can read accurately.
The Y-Pipe end of the downpipe has a thick cast flange as well. The downpipes are made of 304 stainless steel and are tig welded for strength and have tabs that bolt up to the OEM mounting points.
We will be replacing the twin stock intercoolers with this large Greddy front mount. The Greddy unit is huge and takes up as much room as possible for the available area in the nose of the car. The frontal area of the Greddy core is larger and the core thicker.