R35 GTR Speed Density Conversion Kit

The factory MAF sensors max out around 700whp, at which point they can no longer meter the increased air volume. Speed Density is the answer for higher power levels, and a must for anyone who wants to run vent-to-atmosphere blow off valves.

When calibrated properly there is no sacrifice in drivability; your car will drive just like stock. In fact, Speed Density tuned cars are often referred to as the smoothest driving cars, especially on the R35 platform. But to properly calculate SD based fueling, the air intake temperature sensor must move from its pre-intercooler location to a post-intercooler location. This means moving the temp sensor from the intake to the charge pipe.

This kit does exactly that: it relocates the intake air temperature reading from the factory Mass Air Flow housing to the upper intercooler pipe using a replacement charge pipe pressure sensor with an integrated air intake temp sensor.

• 100% Plug and Play, no cutting or splicing
• Harnesses proudly handmade in the USA with automotive-grade TXL XLPE insulated wire and assembled in an ISO 9001 Certified Facility
• We are a Hitachi Japan authorized dealer and use only genuine OEM Nissan/Hitachi sensors
• Custom tuning required
• Optional 4 BAR charge pipe upgrade
• Optional 4 BAR manifold upgrade

Speed Density (Kit A)

Designed for cars that no longer run MAF sensors. Aftermarket intakes from companies like AMS and Boost Logic delete the MAF slots entirely for big power builds and a cleaner engine bay, and Kit A is built for exactly those setups.

Speed Density (Kit B)

Our most popular kit. Kit B allows you to plug the original MAF sensors back in, keeping the factory intake hardware in place for a more OEM look.

How to choose your options:

The first option is your CHARGE PIPE sensor (stock or 4 BAR). The second option is your INTAKE MANIFOLD sensor (stock or 4 BAR).

Stock turbo cars do not need the 4 BAR upgrade. Only cars with upgraded turbos need a 4 BAR sensor in the intake manifold. A 4 BAR sensor in the charge pipe is not required but is great for checking bank to bank boost pressures.

Planning to run a Fuel Pressure Sensor? We highly recommend it. Our most cost effective option is the charge pipe sensor harness, but our most popular is the MAF Bank 1 + SD kit, which combines Speed Density and fuel pressure monitoring in one kit, so you should consider that before purchasing this.