Nissan 370Z Forum - 2010 370Z NISMO Twin Turbo build courtesy of GTM

Some of you may know me; some of you may not. Some of you may agree with what I have posted on this forum; some of you may not. But, I will wager that we all have one thing in common – the desire to modify our beloved imports.

This being the fifth ‘project’ car that I have modified in the past 3.5 years, I wanted to balance cost with performance; a task that has, so far, been very elusive and has taken me a while to figure out. I admit that over the past few years I have bought into a lot of the hype and spent a lot of unnecessary money in the process. Some monies spent were good ‘insurance’ while others were an utter waste. But, this time, I vowed to have the safest build possible while being the most fiscally conservative. Luckily, advances in technology of the VQ platform and some well thought out planning will allow me to reach my goal.

In the past I have turned to tuner shops and the forums to give me the answers that I seek. While these resources have been good, I have found that there is a lot of misinformation floating around and that the almighty dollar is what the modification game is mostly about. These days I tend to build off of my own past experiences as well as (and most importantly) the experiences of others.

So where to start? How does one come to decide on what type of Forced Induction to purchase? Should I go turbo? Supercharger? Which kit? What support mods do I need? Who should do the install/tune? (if not myself as a DIY project) As usual, these are the top tier questions that I struggled with. For me, due to my past experiences, some of the questions were easily answered. Twin turbo is the only way for me. I have purchased two supercharger kits in the past and have been disappointed with both. The linear torque of the supercharger is just too mild for my tastes. I have tried both centrifugal and roots types. Neither produced the torque or power I desired.

Ok, so twin turbo it is. Now, which kit? There are currently three competing kits. One has been out on the market for a short period of time and is only sold in-house (AAM), one has been out for a bit longer and has a bit more press (GTM) and one has just recently been released (GReddy). All of these kits look very promising and are from reputable manufacturers. All seem to be scalable and perform the same when simply bolted on. Comparing apples to apples, I chose the GTM kit over the AAM and GReddy. Why? Here are my reasons:

1. GOALS - I set my power goals at a maximum of 450-475 to the wheel. Though the GTM kit is scalable from 400 to over 1000whp with the Stage 2 through Stage 6 kits, I have found that anything over 450-500whp is a pure waste on the street. Traction issues keep the car slower out of the hole and cause drivability issues that I no longer want. As the street is where I do 100% of my driving, I have no need for anything more than a Stage 2 setup and 475whp. The GTM kit easily met my power goals.

2. QUALITY – There is no doubt that all three kits are of great quality. Some more so than others, of course, but nonetheless, they will all get the job done. The GTM and GReddy kits are both spectacularly designed with what surely looks to be a lot of thought and engineering behind them. The only concern I had with the GTM kit was the spacing of the power train that has to happen. But, I have researched and put my concerns to rest over this issue as it is a moot point and does not affect drivability or functionality of the car in any form or fashion. The down-side to the GReddy kit is the known issue of manifolds cracking which can be a great headache to repair. That and the lesser quality turbos. (IHI vs. Garrett)

3. OPTIONS – As trivial as this might be, for me, I prefer having options for detail items when purchasing a kit. Over the past few years I have learned that unless a manufacturer can cater to my anal-retentiveness and provide a “one stop shop” for all that I need, I will look elsewhere. The fact that I have options with the GTM kit such as black couplers, choice of polished or powder coated piping, choice of polished or thermo-coated intercooler, and optional ceramicoated manifolds and turbo exhaust housings, all at a reasonable cost, was just one more small detail that led me to choose the GTM kit.

4. ENGINEERING – One key factor for me is longevity of the kit that I purchase. A lot of parts are static and do not wear, so with every kit I have researched, these items are seemingly equal when it comes to predicted life-span. But, the major components – the turbos – are what interested me the most and certainly, in this regard, not all are created equal. The GTM kit uses Garrett ball-bearing, water-cooled turbos while the GReddy kit uses journal bearing, oil-cooled turbos. Given that the 370Z is plagued by oil temperature issues, one would think that the oil-cooled turbos would not be a considerable option. GReddy seemingly addresses this with a larger capacity oil pan and optional oil cooler, but I was (am) not convinced this would alleviate the faster degradation of the turbos that will certainly happen without these items.

So now that I had decided what type and which kit, I needed to decide what support mods to purchase. In the past I went all out and bought the best of everything because A) I was told it was what I needed and B) I fell for the hype over particular brands and parts. This time, I decided to approach things a bit differently. I wanted to see what I could actually achieve safely while being cost conscious. So, I spoke with quite a number of tuners/shop owners/vendors/manufacturers and came to the general consensus that for my goals I didn’t need to get fancy. An oil-cooler for the hot GA days, a nice open exhaust including test pipes, larger injectors, an upgraded fuel pump and some colder plugs were all that I needed. I opted to add an AFR gauge, boost gauge, powder-coated piping, thermo-coated intercooler and ceramicoated exhaust manifolds and hot side turbine housings/flanges.

This leads me to the ‘who’ and ‘where’ portion of my decision. In the past I have relied on one company to do all of my work. Over the years I have trusted the shop owner’s advice implicitly. But after a few conversations with him and feeling that I was being steered towards an option that I didn’t feel comfortable with (GReddy kit), I decided to venture out and directly to the source of the kit I had chosen.

After speaking with Sam I came away with the impression that he really knows his stuff and that my car would be in excellent hands. All of my questions, concerns and thoughts were addressed in a thorough and detailed manner. I could tell that he is a busy guy as we were constantly interrupted by his workers asking him questions or clients walking in the door, but never once did he lose train of thought or overlook any of my inquiries. This made me very comfortable as I am an extreme stickler for detail and I could see the same in Sam, even while under duress. He was also very open and took no offense to my probing questions. His level of transparency satisfied my need to know exactly what I was getting myself into and who I would be spending my hard-earned money with.

So this will be my official “build thread”. Any and all questions are welcome. Here are a few pictures to start as well as a video of the first tuning session. For those of you who want to see more of GTM and the shop, click on the second video link. Enjoy!

Notice 479whp on 7psi springs! 8.6psi yielded 518whp which is well over my goal of 450-475whp!