What is GIR and why is it important for Nissan GT-R?
Hydraulic intelligent controller (GIR) is a critical component of the engine lubrication system VR38DETT, which controls oil pressure depending on the load. In stock configuration GT-R R35 Oil pressure often drops at high speeds or under extreme loads (track days, drag racing), which leads to oil starvation and accelerated wear of turbines, crankshaft bearings and camshafts.
Installing a high-quality GIR solves this problem by ensuring stable oil pressure in the range 4.5–7.0 bar even with 7000+ rpm and lateral overloads. This is especially true for tuned GT-R with increased power (550+ hp), where the standard oil pump and pressure relief valve are not up to the task. A correctly selected GIR not only extends the engine’s life, but also allows you to get the most out of the turbo system without the risk of scuffing.
In this article we will look at top 5 GIR for Nissan GT-R, compare their technical characteristics, tell you about the nuances of installation and configuration, and also answer frequently asked questions from owners. The information is relevant for all modifications R35 (2007–2026), including Nismo And Track Edition.
Top 5 GIR for Nissan GT-R R35: comparison of models
The market offers dozens of GIR options, but not all are suitable for VR38DETT in terms of reliability and compatibility. We have selected 5 best models, tested on the track and in everyday use. The selection criteria were: pressure stability, body material (aluminum vs. steel), compatibility with tuning and owner reviews.
- 🏆 N1 Racing Oil Pressure Regulator — the best choice for the track, pressure up to
7.5 bar, aerospace aluminum body. - 💎 Tomei Oil Pressure Control Valve - premium solution with titanium coating, optimized for high speeds.
- 🔧 GReddy Oil Pressure Regulator — universal version with an adjustable response threshold (3.5–6.0 bar).
- ⚡ HKS Super Oil Pressure Regulator — increased throughput, recommended for engines with a power of 600+ hp.
- 🛠️ Cosworth Oil Pressure Kit — complete set with sensors and oil lines, used in racing series.
Below is a comparison table of key parameters. Pay attention to the column "Recommended power" is the maximum output of the engine at which the GIR is guaranteed to cope with the load.
| Model | Housing material | Pressure range (bar) | Recommended power (hp) | Features |
|---|---|---|---|---|
| N1 Racing | Aluminum 6061-T6 | 4.0–7.5 | 700+ | Built-in oil temperature sensor, compatible with VR38DETT And RB26DETT |
| Tomei | Titanium coated steel | 3.8–6.8 | 650+ | Adjustable without removal from the engine, supplied with Viton O-ring |
| GReddy | Aluminum | 3.5–6.0 | 600 | Easy installation, compatible with stock oil filter |
| HKS | Steel | 4.2–7.0 | 750+ | Increased throughput, recommended for drag racing |
| Cosworth | Aluminum 7075-T6 | 4.5–8.0 | 800+ | Complete kit with oil lines and sensors, used in GT3 |
Important: GIR from N1 Racing And Cosworth require mandatory calibration after installation - without this, the pressure may exceed safe values, which will lead to damage to the seals and gaskets.
- N1 Racing
- Tomei
- GReddy
- HKS
- Cosworth
- I haven't decided yet
Which GIR is suitable for your driving style?
The choice of GIR depends not only on engine power, but also on how you operate the car. For example, for everyday driving Suitable for occasional trips to the track GReddy or Tomei with moderate pressure settings. But for racing disciplines (time attack, drift, drag) a more “tough” regulator is needed — N1 Racing or HKS.
- 🚗 City/Road: GReddy or Tomei (pressure 4.0–5.5 bar). Sufficient to protect the engine without putting undue stress on the system.
- 🏁 Track day (1–2 times a month): N1 Racing (5.5–6.5 bar). Optimal balance of reliability and resource.
- 🏎️ Racing/Time Attack: Cosworth or HKS (6.5–8.0 bar). Maximum protection under extreme loads.
- 🔧 Tuning 700+ hp: Only Cosworth or N1 Racing with a modified lubrication system (additional nozzles, oil accumulator).
Warning: if your GT-R used exclusively in the city, GIR installation with a pressure higher 5.5 bar may lead to oil leaks through seals and gaskets not designed for such loads. In this case, it is better to limit yourself to replacing the oil pump with N1 or JUN.
⚠️ Attention: On engines with a mileage of more than 80,000 km, before installing the GIR, be sure to check the condition of the oil pump and pressure relief valve. A worn-out pump will not be able to provide the required pressure even with a new regulator.
Step-by-step instructions for installing GIR on Nissan GT-R R35
Installing a GIR is a procedure of medium complexity that requires accuracy and consistency. If you have experience working with a car, you can do it yourself, but for racing trims (For example, Cosworth) we recommend contacting a specialized service.
Before starting work, prepare:
- 🔧 A set of sockets and keys (required)
10 mm,12 mm,14 mm). - 🛠️ Torque wrench (tightening torque
25–30 Nm). - 🧴 New motor oil (Motul 300V or Red Line) and filter.
- 📋 Connection diagram (included with GIR).
Sequence of actions:
- Drain the oil and remove the pan (if necessary, the oil pump).
- Remove the stock pressure relief valve (located on the pump body).
- Install the new GIR according to the diagram using new o-rings.
- Connect oil lines (if required) and pressure sensor.
- Fill with new oil, start the engine and check the idle pressure (
2.0–2.5 bar). - Test at high speeds (from
5000 rpm) and under lateral loads (turning).
Check the compatibility of the GIR model with your model year GT-R|
Buy replacement O-rings (Viton or Teflon)|
Prepare a container for draining the oil (minimum 8 liters)|
Have a pressure gauge handy to check your pressure|
Take a photo of the stock valve wiring diagram -->
⚠️ Attention: If, after installing the GIR, the pressure at idle speed exceeds 3.0 bar, stop the engine immediately and check the governor settings. This may indicate spring failure or incorrect assembly.
Setting oil pressure: optimal values for different modes
Correct adjustment of the GIR is the key to engine longevity. Oil pressure must correspond to the load, but not exceed safe limits. Below are recommended values for different scenarios:
| Operating mode | Pressure at idle (bar) | Pressure at 5000 rpm (bar) | Max. pressure (bar) |
|---|---|---|---|
| City/highway | 2.0–2.5 | 4.0–4.5 | 5.0 |
| Track day (moderate) | 2.2–2.7 | 4.5–5.5 | 6.0 |
| Racing/time attack | 2.5–3.0 | 5.5–6.5 | 7.0 |
| Drag racing (700+ hp) | 2.8–3.2 | 6.0–7.0 | 7.5 |
To adjust the pressure use adjusting screw on the GIR body. Turning clockwise increases the pressure, turning it counterclockwise decreases it. N1 Racing And Cosworth equipped two springs (main and auxiliary), which allows more precise control of the pressure curve.
After setting the GIR, perform a test drive with oil pressure logging (via ECU or external sensor). If the pressure drops below 3.5 bar at 6000 rpm, the oil pump needs to be adjusted or checked.
For engines with forced turbines (For example, Garrett GTX or BorgWarner EFR) it is recommended to install additional oil accumulator volume 1–2 liters. This will help avoid oil starvation during sudden maneuvers.
What happens if you configure the GIR incorrectly?
Too high a pressure (>7.5 bar) can lead to extrusion of the crankshaft and camshaft seals, as well as damage to the oil cooler. Too low (<3.5 bar at high speeds) is fraught with scoring on the cylinder walls and destruction of turbine bearings. In both cases, a major overhaul of the engine will be required, costing from 500,000 rubles.
Frequent mistakes when choosing and installing GIR
Even experienced owners GT-R sometimes they make mistakes that negate all the advantages of GIR. Here are the most common ones:
- 🔄 Ignoring engine mileage. On engines with mileage >100,000 km, installing GIR without preliminary diagnostics of the oil pump and valves often leads to leaks.
- 🛑 Use of stock oil lines. Rubber hoses are not designed for pressures >5 bar. For GIR you need metal lines or reinforced hoses AN-10.
- ⚖️ Incorrect calibration. Many people forget that blood pressure needs to be checked. on a hot engine (oil temperature
90–100°C). - 🧴 Saving on oil. GIR requires oil with high viscosity at operating temperatures (for example, Motul 300V 15W-50 or Red Line 20W-60).
The most dangerous mistake — installation of GIR without replacing the oil pump on used engines. Stock pump GT-R wears out after 60,000 km, and even the most expensive regulator will not be able to compensate for its low performance.
⚠️ Attention: If after installing the GIR you notice metal shavings in oil or knocking in the engine, stop the vehicle immediately. These are signs that the pressure has not been adjusted correctly and the bearings have already begun to wear out.
Additional modifications for maximum engine protection
GIR is only part of the protection system VR38DETT. For complete reliability, we recommend considering the following modifications:
- 🛢️ Oil accumulator. Eliminates oil starvation under extreme overloads (for example, when cornering on a track).
- 🔥 Increased volume oil cooler. Maintains stable oil temperature (
90–105°C) even in hot weather. - 🌀 Additional oil pump. Relevant for drag racing, where a standard pump does not have time to pump oil.
- 📊 Pressure logging system. Allows you to monitor parameters in real time (for example, via Haltech or AEM).
For engines with power 700+ hp installation required dry sump (dry sump). This system completely eliminates oil starvation, but requires serious modifications and costs from 300,000 rubles.
The combination of GIR + oil accumulator + radiator increases engine life GT-R by 30–40% even with regular track days.
FAQ: answers to frequently asked questions about GIR for Nissan GT-R
🔧 Do I need to change the oil pump when installing the GIR?
If the engine mileage exceeds 80,000 km - necessarily. Stock pump GT-R Loses performance due to wear of gears and bearings. For tuned engines we recommend pumps N1 or JUN.
⚠️ What oil pressure is considered dangerous for VR38DETT?
At idle speed - above 3.0 bar (risk of squeezing out the seals). At high speeds - below 3.5 bar (oil starvation). Optimal range: 2.0–2.5 bar at idle and 4.5–6.5 bar at 6000 rpm.
🛠️ Is it possible to install GIR yourself?
Yes, if you have experience with GT-R and a special tool (torque wrench, oil pan puller). For models Cosworth And N1 Racing We recommend professional installation due to the complexity of setup.
💰 How much does it cost to install GIR in the service?
The cost of work varies from 15,000 to 40,000 rubles depending on the GIR model and the region. In Moscow and St. Petersburg the average price is - 25,000–30,000 rubles (including oil pump diagnostics).
🔄 How often should you check the oil pressure after installing the GIR?
The first 1000 km - every 200–300 km. Then - once every 5000 km or before each track day. Use an external pressure gauge (eg AEM), since the standard sensor GT-R inaccurate