turbos.....

[Ruan]

so basically if your driving a a constant steady speed (say 60-70) and a boost controller won't open because it isn't clever enough to open then surely the backpressure is going to push the heat back and engine will overheat and or overload the cooling system?
because if that's the case even driving long distance at steady speeds would provoke problems with the vnt?

Well, the biggest problem isn't so much the heat, it's the pumping losses that the engine endures, it'll be pumping all that gas at high pressure when it's not needed, high inlet temperatures due to the boost and yes, it can overheat the head as the gas can't get out fast enough...

Any steady speed will cause the problem, but it's very noticable on the motorway - or just cruising...