This GT-R really was quite the “low” power build. It’s always fun when you get a call from a super smart guy that has built and tuned his own cars for years, requesting you to take on his own R35 project start to finish. I love helping people of all experience levels, but it certainly makes me feel accomplished when someone I feel really has a grasp on what it takes to build a high HP GT-R chooses us from start to finish with their project.
The goal was an animal of a dual purpose car that he could run on the circuit track and then turn up to make well over 1000hp at the drag strip and on the street. I wanted to build him something with super smooth power applications, quick but not too quick transient boost, and great reliability. High HP road race cars are tricky to get right. You want something that is going to spool quickly AND have quick transient boost response. Lots of people think those are the same thing but they really aren’t. At the same time you can’t build something that comes up so quickly that it shocks the tire in the middle of a corner while the power is coming in. Some of this is for sure in the tune, but the combination of the right engine, cam, turbo, and AR housing is equally as important as a very proper road race tune.
So for this build we spec’ed out a 4.1 stroker. We specifically built it with oiling modifications for the high lateral Gs the car is going to see. Then we did a fully custom spec port job combined with a smaller cam than we would usually use on an all out “drag” version of this build. As I said above, working out the combination to make it WORK for the client.
Let me branch off on this subject and add a little. Lots of people underestimate the importance of not only a shop with racing pedigree and history, but also experience with all kinds of different setups. What the community sometimes overlooks is that we fix, tune, diagnose, and help customers with every setup under the sun you can imagine… literally on a weekly basis. From different engine combos, to cams, head porting, turbo kits, transmissions, tuning platforms… we see it all! We are blessed with continually accumulating a knowledge base with an incredibly diverse range. What that does for us is gives us what I feel is the widest range of experience of any GT-R shop worldwide.
Onward with the setup. With the 4.1 we wanted a turbo kit that would meet the balance of needs. This was honestly a no brainer! The Extreme Turbo System (ETS) Pro1400 was the way to go. The Pro1400 packs a LOT of punch and is a very, very efficient package. There are turbo kits out there that you can push to make power, then there are the turbo kits that do it efficiently. We can see that in things like drive pressure, boost pressure, and timing how hard we are leaning on this particular kit/combo to make the goal HP. The Pro1400 includes not only what I feel is the best manifold on the market, but also smoothly designed 3.5” intakes and 3.5” downpipes which make a great deal of difference. Combine that with the external WG dumps so that the downpipes don’t have to be over worked at lower boost and the combination is simply awesome!
We combined the mechanical portion with a pretty unique Motec M1 setup. The Motec gives us all kinds of control over not only the ECU strategy but also of course the ABS side of the traction control and now the output to the FWD clutch. The tuning that went into this road race build was for sure something I’m proud of. We installed a user selectable traction control switch so that based on the tire and track the customer could control his “intrusion” amount of the motorsports style closed loop traction control. We also provided him with two maps to load up to the Motec. One of them being a street map and the other being an all in one circuit map. The two tunes completely change the way the power comes in and how progressive it is. They also change how the traction control works and how the FWD clutch implements its effect on traction mid corner. Needless to say we had fun with this one!
Below you will find some pictures and the dyno graph information. The customer has had his car back for a couple months and is enjoying the crap out of it!
Feel free to ask any questions that you may have! Thanks for taking the time to read.