Infiniti first released their G37 model back in 2008 to replace the outgoing G35. The G37 lasted from 2008-2013, earning itself a formidable reputation as a fun luxury car with solid performance. Under the hood, Infiniti put a stroked version of the engine from the G35, the VQ37VHR. The naturally aspirated engine makes 330 hp and 270 ft-lb inside the G37, and is the same engine Nissan put in their high-performance 370z and 370z Nismo.
This guide is going to cover the 6 best Infiniti G37 upgrades available. We will look at everything it takes to turn your run-of-the-mill G37 into a high-performance machine. There are a lot of different paths for upgrades, and we are going to cover the ones that will give you the most bang for your buck. Let’s see what it takes to build out everything from 300whp to 1,000whp.
Engine Power Limits
As you might expect coming from a Nissan performance engine, the VQ37VHR has some serious power potential. A completely stock version will typically dyno at 270-280 whp and 230-240 wtq, and that doesn’t even come close to touching what it can handle. These engines can take a serious beating with some real power before having issues.
Generally, the limit for the stock internals is about 600-650 whp, or more than double what the stock tune makes. The block is thought to be good for another 150 whp more, up to about 800 whp before it starts to fail. This means that you can max out bolt-on Infiniti G37 upgrades without having to worry about running into issues. You can also run a considerable amount of boost through forced induction before needing to worry about failures due to power, too.
Infiniti G37 Performance Upgrades
- Intake
- High Flow Cats/Test Pipes
- ECU Tuning
- Cat-Back Exhaust
- Suspension Upgrades
- Forced Induction
1) Upgraded Cold Air Intakes Intakes
One of the easiest Infiniti G37 upgrades is adding an intake. Intakes are one of the most popular mods for any car, and they perform quite well on the VQ37VHR platform. For most builds, an intake is the first upgrade to be done. Keep in mind, the VQ37VHR engine design has dual intakes, one for each the left and right side.
Upgraded Cold Air Intake Benefits
- +5-10 whp/wtq
- Increased airflow
- Increased filter surface area
- Reduced intake temps
- Louder engine noises
There are a ton of benefits to putting a cold air intake on your G37. The most basic thing is going to be an increase in power, and intake adds about 5-10 whp when tuned. This is due to the larger diameter intake tubing and increased air filter size, which allows more air to be sucked in at an increased flow rate. However, the big improvement from cold air intakes is going to come when underhood temperatures start to rise and/or when you add more mods to your build.
When the engine bay starts to become heat-soaked, cold air intakes allow the engine to receive cooler air from the bottom of the front bumper area. In addition, when you start to add exhausts, headers, or forced induction, the improved flow from aftermarket intakes helps them make more total power. CAIs also show a small improvement in fuel economy and a slight increase in engine noises from under the hood.
Long Tube vs Short Ram
There are two main types of intakes for the G37: long tubes and short ram. The long tube intakes are also cold air intakes. They route the intake filters very far away from the throttle bodies and down below the front bumper. Short ram intakes on the other hand do the opposite, they shorten the length of the intakes to make them as small as possible. The idea is that less piping means the least restriction possible to get air directly into the engine.
On the G37, we definitely recommend going with long tube/cold air intakes over the short ram style. The short ram intakes leave the filters sitting right in the middle of the hot engine bay. This means that as soon as the engine bay starts to heat up or ambient temperatures rise, the short ram quickly turns into a hot air intake. On the other hand, the long tube intakes add a lot of extra piping to put the filter way down in the bay just behind the front bumper. This allows them to constantly grab the coolest air possible.
2) Upgraded High Flow Cats/Test Pipes
After an intake, changing out the stock catalytic converters is one of the best Infiniti G37 upgrades possible. Especially for older G37s that are now approaching a decade and a half of ownership, where the stock cats are beginning to fail anyway. High flow cats (HFC) are a pretty inexpensive modification that is relatively easy to install by yourself.
Benefits
- +10-20 whp/wtq (High flow cats)
- +10-25 whp/wtq (Test pipes)
- Increased exhaust sound
- Reduced exhaust backpressure
The main benefit of changing to Infiniti G37 HFC or test pipes is the power increase. Depending on which you go with, you will see at least 10 whp with a max of 25 whp. Pretty substantial increases for just a small piece of pipe! G37 HFC and test pipes offer very significant improvements to both acceleration and top-end power. Whereas intakes usually only deliver more towards the top end, HFC and test pipes will bring you increased low-end torque and responsiveness, too.
You will also definitely notice an increase in exhaust volume after replacing the stock cats on the G37. Resonated HFC and test pipes will mitigate some of the volume increase and add more depth to the tone, but regardless it will be louder, so be prepared.
High Flow Cats vs Test Pipes
Test pipes and HFC pipes are identical with only one difference: test pipes are catless. They both connect the exhaust headers to the y-pipe part of the exhaust, but HFC (obviously) have catalytic converters in them.
The difference between catted and catless pipes has implications for both power and legality. Test pipes will make more power than HFC because they are catless. However, the difference is honestly pretty minimal, with maybe 5 whp at the very most. They are also illegal because of the lack of cats. This means they can only be used on track or competition vehicles and not on street-driven G37s. HFC retains the catalytic converters, making them emissions-compliant for most places.
We recommend going with HFC over test pipes. They still offer basically the same performance but still retain legality. It is important to note there are some jurisdictions where even HFC are illegal though, so make sure to check up on all local and state laws before any purchases.
3) Upgraded ECU Tuning
Now that we have looked at intakes and HFC/test pipes it’s time to look at one of the most fundamentally important Infiniti G37 performance upgrades possible, ECU tuning.
Benefits
- +15-25 whp/wtq
- Ability to switch between multiple maps
- Maximize gains from other mods
- Safely tune for other mods
There are so many advantages to tuning the VQ37VHR it’s hard to fathom. Not only will you be able to squeeze more power out of your G37, but you will be able to do so as safely as possible. Just tuning a bone stock G37 will add 15-25 whp/wtq, and that’s just the tip of the iceberg.
When you add other mods, like the aforementioned intakes or HFC/test pipes, they change the airflow and air-to-fuel ratio inside the combustion chamber. While the stock ECU can handle these changes, they don’t take complete advantage of everything the new mods have to offer. In comes ECU tuning. ECU tuning allows tuners to modify things like ignition timing, VVT timing, and air-to-fuel ratios. By modifying these parameters, tuners can get more horsepower and torque from the VQ37VHR.
This means that while your intake and exhaust may have netted a combined 30 whp, with a tune that can increase to 45 whp or even 50 whp. The more mods the more a tuner can take advantage of increased air flow and fueling to make more power. There are some mods, like forced induction, that absolutely require tuning to be safely run on the G37. Without a tune, you can risk severe engine damage from it not operating under the best parameters for your mods.
ECU Tuning Recommendations
- EcuTek Tuner for G37
- UpRev Tuner for G37
There are two basic options for ECU tuning on the G37: chip tuners and custom tuners. Chip tuners are very rudimentary devices that offer minimal horsepower and torque gains. They are sold as one size fits all per vehicle and are not customized for specific setups. On the other hand, custom tuners allow for the individualized tweaking of various parameters for specific setups.
We don’t really recommend chip tuning for the G37 platform because of the availability of custom tuners. We do highly recommend custom tuners. For custom tuning on the G37, the process is to buy a custom tuner device and either make the parameter changes yourself or have a reputable tuning professional (also known as a tuner) make them – either in person or via email.
There are a few custom tuning options out there, but the best for the VQ37VHR-equipped G37 are EcuTek and UpRev. Both of these are handheld devices that plug into your car and computer. After purchasing either, users can make their own adjustments or contact a reputable tuning professional who is familiar with the G37 to do them.
4) Upgraded Cat-Back Exhaust
An upgraded cat-back exhaust system is a great way to improve the sound of your G27 while also picking up a bit of power and torque. Cat-backs connect directly to the cat/HFC/test pipe section of the exhaust and extend all the way back. They consist of the y-pipe, mid-pipes, and axel-back portions.
Benefits
- +5-10 whp
- +5-10 wtq
- Louder exhaust volume
- Customizable exhaust tone
While Infiniti G37 cat-back exhausts will deliver a small bump in power (5-10 whp/wtq), the main reason most people install them is the large increase in exhaust sound. Cat-backs offer larger diameter piping than stock at 2.5”-3”, which drastically increases the volume. It makes the tone deeper, more raspy, and more aggressive sounding. They are also typically made of 304 stainless steel, making them 10-25 lbs lighter than the stock exhaust on average.
5) Suspension Upgrades for G37
Now that we have added some power to the VQ37VHR, it’s time to talk about how to match the suspension to properly handle it. The two main suspension upgrades for the G37 are coilovers and sway bars. They each help with body roll and stabilization, allowing you to be more in control of the vehicle at all times.
Coilovers
Coilovers mainly improve handling by lowering the ride height and stiffening the spring rates. They can be adjusted for track, competition and daily driver use. Previously, we took an in-depth look at them in our G37 coilovers guide.
Sway Bars
- Stiffer than stock
- Lighter than stock
- More durable than stock
- Adjustable for different drive styles (track, daily driving, competition, etc)
Sway Bars (front and rear) are one of the most important suspension upgrades that can be made to the G37. While they might seem like they are not very useful, they actually have a huge effect on drivability. Aftermarket G37 sway bars improve handling by controlling how the car transfers weight during cornering. The stiffer design stops the sway bar from flexing and twisting, which keeps the car more planted and balanced. This reduces unwanted problems like too much body roll and understeer, and allows the driver to more easily control acceleration while cornering.
6) Infiniti G37 Forced Induction
Now for the ultimate Infiniti G37 upgrade: forced induction. In layman’s terms, forced induction increases the amount of air flowing in and out of the engine. It does this by artificially flooding more air into the combustion chamber through either a turbocharger or supercharger. The more air that is flowing into the combustion chamber the more fuel can be added, which increases power output.
Additionally, turbochargers and superchargers (non-roots style) compress the air before pushing it into the engine (roots style it compresses post-supercharger). Compressed air is denser than atmospheric, which means it has more oxygen. With more oxygen even more fuel can be burned, which equates to more total power. This is why turbochargers and superchargers increase power so much, by forcing more air and fuel into the engine.
Forced induction kits are not cheap and usually range in the $6,000+ range. Unfortunately, there just aren’t any other ways to add big power to the VQ37VHR. Bolt-ons will give you an additional 40-60 whp over stock, but besides that forced induction is really the only way to increase power.
Benefits
- +100-1,200 hp/tq
- Massively increased response
- Improved power throughout entire RPM range
Turbochargers vs Superchargers
Superchargers and turbos work differently as Infiniti G37 upgrades but achieve the same goals. Turbos are connected to an engine exhaust manifold. They use exhaust gasses exiting the manifold to operate an air compressor. This air compressor takes ambient air, compresses it to a specific PSI, and pushes it into the engine. All turbos work this way, except electric turbos, which use electricity instead of exhaust gasses to power the compressor.
Superchargers work almost the same way, but they are usually belt driven rather than exhaust gas driven. There are three types of superchargers: roots, twin-screw, and centrifugal – with centrifugal being options for the G37. Centrifugal superchargers are almost identical to turbochargers except for being belt driven.
Forced Induction Supporting Mods
If you plan on upgrading your build to include forced induction as an Infiniti G37 upgrade you will need to add some supporting mods, too. You will generally want to have full bolt-ons done first, but this is somewhat dependent on your specific kit. You will also have to beef up your fueling system to keep up with the addition of boost. Also, after enough power gets added, the internals and block start to need reinforcement.
To improve your fueling system, at a minimum you will need a larger fuel pump and fuel injectors. For builds keeping peak power under 600-650 whp the internals are okay. However, anything bigger will need stronger pistons, connecting rods, and head studs – at the minimum. The block is generally thought to be good until around 800 whp, so that will only need to be upgraded on the biggest of builds.
The manual transmission holds up to power very well and is exceptionally stout. The automatic on the other hand has a propensity to crater after 500 whp. It needs to be “built” with stronger internal components to take more power.
Most kits come with everything needed, including all oil and coolant lines, and some include optional items like intercoolers. Intercoolers are great for cooling down the charge air (compressed air) on its way into the engine. Colder air, like denser air, has more oxygen which means more ultimate power.
Summary
The Infiniti G37 is already a fun car to drive in its stock form, but it is just begging to be modded. You can quickly turn your G37 from a 270 whp economy sedan into a fire-breathing 1,000 whp dragon with just a few mods. You can also keep your build much more mild and focus on smaller amounts of power for a daily driver. Whatever your goals, this guide can help you reach them.
Intakes, exhausts, and tuning are the best bolt-ons to increase power on the G37. They each add about 10-20 whp alone, and can combine to make an additional 40-60 whp over stock (310-340 whp total). For anyone looking for more power, the answer is forced induction. The Stillen supercharger system offers a moderate increase in power to 400 whp. Either the Soho or AAM will take anywhere from 450 whp to 1,000+ whp, depending on the specific kit.
Suspension upgrades are also important, and adding coilovers and/or sway bars really help with handling and drivability. If you’re even thinking about adding forced induction you can’t neglect the suspension upgrades. Your car might be powerful, but it’s all about how you can control it and drive it to really make it fast.
