TURBO SWAPS

Some KKK turbos as fitted to various Vauxhalls are interchangeable, so you can fit a larger turbo, uprate the ancillaries, get a remap and produce more performance. The Vauxhall VXR’S KKK K04 turbo, for example, is a straight swap onto the standard exhaust manifold for the Z20LET engine. Just fitting this larger turbo without a remap or uprated ancillaries produces more torque, but for the best results, a larger air intake from a diesel Vectra C, larger VXR injectors, a VXR mass airflow (MAF) meter, a larger intercooler and a remap will get the most out of this upgrade, with power output increasing from 190bhp to around 280bhp.

The standard Garrett GT1549 turbo on the L-series diesel engine (as fitted to the Rover 200/400 and MG ZR/ZS) is capable of producing up to 155bhp and 240lb ft of torque with many of the modifications outlined here. Dark Ice Designs has run a GT1752 with 185bhp and 260lb ft of torque on an L-series engine for three years and haven’t encountered any problems. Expect to pay around £150 for a Chinese-made GT1752 turbo to use with Dark Ice Designs’ conversion kit (£74.99), budgeting another £100+ to modify the downpipe.

The later variable vane turbos (VNT or VGT) are becoming increasingly popular to fit on older engines with earlier turbos. Such a turbo often requires a controller to operate it, such as Digibooster-s from Dark Ice Designs at £129.99.