Walkinshaw has unveiled its long-awaited supercharger kit for the Silverado 1500 range, boasting the ability to increase power by over 50 per cent.

The kit has been developed in conjunction with Harrop, which has been working with Walkinshaw for over 25 years on supercharged and performance packages.

This can add a maximum of 146kW and 215Nm to the existing power of any Australian-delivered Silverado 1500.

“Pricing hasn’t been completely finalised, but it’ll start at around AU$20,000,” said Ricciardo Pontonio from Walkinshaw Performance.

“There’s already been a lot of interest in the package, and it should be publicly available by Christmas,” he said.

The blower itself is an Eaton TVS2650 supercharger, with a closed circuit water-to-air intercooler system that has large radiator at the front of the car – as well as twin dual-pass intercooler cores within the supercharger manifold.

It also features an Active Bypass Controller, which controls the boost from the supercharger and also the timing of the Bosch water pump used for the water-to-air intercooler.

In standard form, the 1500 Silverado claims power figures of 313kW and 642Nm from the 6.2-litre EcoTec V8 at the engine.

Harrop ran a completely standard 1500 LTZ on their hub dyno as part of testing, revealing figures of 260kW and 525Nm at the hubs.

A second Silverado 1500 fitted with the supercharger kit and a standard exhaust boosted power to 385kW and 713Nm, running a maximum of 8psi of boost.

A third was also tested, this time fitted with both the supercharger kit and the optional Walkinshaw full exhaust package. The addition of the exhaust saw power jump even further to 406kW and 740Nm, with the same 8psi boost pressure.

The Walkinshaw exhaust kit fitted to that vehicle used the twin cat-back system already available from Walkinshaw (for $3200) and a header and catalytic converter kit, which is expected to be available by the end of the year.

The supercharger kit is suited to both the LTZ and Trail Boss 1500 Silverados current sold by GMSV, and can also be added to Walkinshaw’s existing Fury packs.

The V8 mills require no internal modifications to accommodate the supercharger, with only a recalibration of the ECU needed that still retains all the factory features – including stop-start.

As for performance, Walkinshaw states that a Silverado 1500 fitted with both the Supercharger kit and its optional exhaust recorded a best 0-100km/h time of 4.76 seconds, with a quarter-mile best of 12.66 @110mph (177km/h).

At the same test, Harrop clocked a standard 1500 LTZ with figures of 0-100km/h in 6.03-seconds and a quarter mile of 13.96 @99mph (159km/h).

For reference, when Wheels tested a standard Silverado 1500 LTZ at the same drag strip early last year, the best results recorded were 6.4-seconds from 0-100km/h, and 14.5 @98mph (158km/h) over the quarter mile.

Fuel economy is stated at 11.5L/100km from the supercharger kit, but our testing of naturally-aspirated Silverado 1500s has yet to yield a figure better than 12.4L/100km.

Pontonio from Walkinshaw Performance also confirmed that the firm will inherit any warranty period still left on a 1500 Silverado fitted with the kit. “The 1500 comes with a three year or 100,000 kilometre warranty from GMSV, so we will honour the remaining warranty period for owners who install the Walkinshaw kit.”

The package has been in development for the Silverado 1500 since 2019, but has been delayed due to the parts shortage currently affecting the industry due to COVID-19.

Current or potential Silverado 1500 owners who are interested in the supercharger package can register their interest early through Walkinshaw’s website or a brand distributor, and fitting of the kit can be arranged through GMSV dealers on pre-delivery Silverado 1500s.