DBS 6 steel bypass plate, bolts to square thermostat housing on 'front of engine side', hose outlet connects to water pump bypass, this plate has no part number shown in the parts book but shown. Not for Later DBS that has the plate without the hose outlet or a blanked off bypass on the pump & plate. Finished in Gloss Black, choice of 3 thermostats, square & diamond gaskets included

Made for modern bypass style thermostats that we sell which is what AM designed it for - Not the later & incorrect thermostat from the later car without the bypass hose.

Exclusive to Four Ashes

Rough Description of how the bypass system works

A thermostat is placed between the engine and the radiator to make sure that the coolant stays above a certain preset temperature.  As the engine warms up the coolant will be below the thermostat temperature or if the coolant temperature falls below this temperature, the thermostat blocks the coolant flow to the radiator, forcing the coolant instead through a bypass directly back to the engine (normally sucked into the water pump) , this has the effect of quickly raising the temperature to or back to the thermostat temperature.  The coolant will continue to circulate like this until it reaches the design temperature, at which point, the thermostat will open a valve and allow the coolant back through the radiator.

So in effect it makes the cooling system more efficient.