Foot to the floor. Dab the brakes. Exit the bend. Back on the gas. And bang – there’s the rev limiter again. The Fondeo was really flying – for a family wagon with a mere stage one package it’s remarkably fast – but it wasn’t making enough boost. Stupid turbo.
Indeed, when AET Motorsport added a superb Peron map a few weeks ago, the techie guys reckoned there was some kind of hardware fault with my car – maybe a tired turbo, perhaps a failed actuator or, most likely, a worn-out dump valve. Whereas the map would normally tell an ST250’s ECU to request 1.6bar of boost, mine was running at 1.4bar, in turn peaking at 258.7bhp at the hubs.
AET’s answer was a to bin the standard valve in favour of a Turbosmart Kompact Shortie, which is a mechanical valve with O-ring sealed brass piston and billet aluminium body rather than the OE part’s plastic case and flimsy diaphragm.
Standard dump valves tend to become brittle with heat cycles, and a tuned car with increased boost pressure naturally generates more heat; similarly a weak spring will stop staying open under boost. A particularly knackered valve could be whistling or make the car feel laggy (due to the turbo working harder to meet target boost pressure).
The Turbosmart solves any such worries, providing better boost response and potential to handle 2bar (30psi). Which means it’s an essential upgrade for any modified ST250 – and crucial for my forthcoming stage two conversion.
Originally I’d hoped to include a small Fast Ford fitting guide, but there were two problems: first, the Turbosmart is a direct replacement, so it’s just a case of dropping the underbody shield and undoing a few bolts; second, it’s hard to see the valve, never mind point a camera at it – AET’s Patrick tackled most of the job by feel rather than sight. If you’re doing the job on your back, you may find it preferable to remove the offside front wheel.
Visually, my old OE valve appeared to be okay but the Turbosmart said otherwise, immediately raising boost to 1.55bar and refreshing my admiration for the sublime Peron remap.
Did I really call it a stupid turbo? Not now there’s a Turbosmart on board.