ISR Performance RS T25/28 Turbo Kit - 99-05 Mazda Miata NB 1.8L

The ISR Performance RS T25/28 turbo kit for the 1999 to 2005 Mazda Miata NB 1.8L is one of the more complete bolt-on turbo packages available for the BP engine, and it lets you keep your air conditioning. ISR built it around compact T25 and T28 GT style turbochargers and ships it with the proven ISR RS T25/28 turbo already in the box, so the hard parts are sorted before the car goes on the lift.

How the Miata turbo kit is built

• Full tubular schedule 40 turbo manifold, chosen over thin cast or tube designs to resist cracking
• 304 stainless steel exhaust components including the turbine O2 housing and downpipe
• Chassis specific intercooler with a mounting bracket for a rigid, rattle-free installation
• Fully polished aluminum intercooler piping
• AN oil feed and water lines, plus an AN turbo drain line with a 10AN aluminum weld bung for the factory oil pan
• Modular hotpipe that accepts ISR, HKS, GReddy and Tial blow-off valve flanges (flanges sold separately)

On a completely stock BP 1.8 engine this setup has produced 210 rwhp at 8 psi of boost, and ISR publishes the dyno graph from that 100 percent stock test.

Fitment

1999-2005 Mazda Miata NB with the 1.8L BP engine.

What comes in the kit

• ISR RS T25/28 turbocharger
• Schedule 40 bottom mount turbo manifold
• Intercooler and piping kit
• Turbine O2 housing and downpipe
• Full oil and water turbo lines with 10AN aluminum weld bung for the oil pan
• AFM delete intake with air filter

Before you install

This kit was designed with aftermarket ECUs in mind and is meant to run with a MAP sensor; the AFM delete intake removes the factory airflow meter. A 2.5 inch hole must be drilled for intercooler pipe routing. Plan on a proper tune before adding boost to the engine.

All ISR Performance products are designed for off-road use only.