BTCC, WRC, WTC, World RX, these are some of the series Mountune and their team’s engines have conquered, let’s get an insight into how.
While 600HP might not seem like a large output these days, like WRC engines World RX (Rallycross) builds are limited by a 45mm air restrictor leaving the teams to focus on getting as much power and torque as possible on tap at lower RPMs. David Mountain of Mountune runs us through some of the considerations and figures that go into this, including ensuring the engine stays sealed with up to 250 Bar (3626 Psi) of cylinder pressure which helps produce 850N-m low in the rev range.
Interestingly after trying many different sealing techniques including Coopers, Wills and BreyuimmrRings Mountune has found MLS cylinder-head gaskets to be best for the task, These MLS gaskets are not from your local parts supplier and instead are produced by ElringKlinger to Mountunes specifications.
The turbochargers used are also motorsport specific Garrett TR30R units which do not need to fit OEM rules and regulations enabling the use of lighter and thinner materials. Again these units are built to the specifications required for the application/engine to give the best performance. While such options are not cheap, David notes that during the Group A rally days where regulations dictated the use of OEM turbochargers, it was not uncommon to carry replacements in the car to use at the end of each day.
Also discussed is the anti-lag system employed on engines for Rally and Rallycross applications including some of the evolution to where things are at today, the oiling systems which can be regulation driven and how staged injection is utilised.