Go to Megasquirt


Supply, support and installation of MS2, Microsquirt, MS3, MS3-Pro (1st gen, EVO & Ultimate) and Gold-Box ECU’s. UK Based 24/7 support available.

Go to Diagnostics


Diagnostics with dealer level and advanced equipment such as oscilloscopes and signal generators. Also canbus, profibus, modbus and KWP logging and decoding.

Go to Tuning


Mapping and tuning of OEM & aftermarket engine and transmission control systems in both automotive and industrial sectors.

Go to Products


Specialising in the Lexus UZ Series. Standard and aftermarket parts from Mahle, Cometic, ARP, Carrillo, Spool and ACL. Various kits in stock, knock sensor, IAT, COP conversions.

Underground Performance

About Us

Specialising in aftermarket performance modifications on Japanese vehicles - Underground Performance was founded in 2012. With 10 years of experience with Megasquirt ECU's, we now offer UK based assistance for all MS products. All aspects of custom wiring are covered, from standalone fitment to complete replacement looms for classic to track vehicles.