Neverlift

Petrol; but power train is almost immaterial when building a race car.

Much more severe than that; have built many race cars, lots with rose jointed suspension, you get more noise and feel, but not really vibration. this feels like a broken drive shaft together with broken gearbox mount (it’s not; have checked and double checked them). if you get out of the throttle it goes; even part throttle there is no vibration… somehow feel it’s engine/turbo related but can’t see any signs of boost dropping off etc., a puzzle….

Help needed; Having lifted the engine and gearbox out of my PD130 VRS (to rebuild the box primarily), took the opportunity to fit PD150 Head Bolts (as recommended here) and new timing belt + water pump. Also deleted the EGR (it had obviously been deleted once before in its life, but previous owner had put it back?), added Poly bushes all round, BC Coli overs, Whiteline rear Anti Roll bar and a pair of Audi TT front callipers and Tarox disks. Popped the drive train back in and was behaving very strangely; loads of boost (and Power) then no power or boost and then back again, all intermittently and a horrible vibration seemingly through the rear engine mount area on Wide Open Throttle? Eventually with the help of Bill at 'the diesel specialist' in Southampton they have found the issue to be 'sludge' in the fuel pump pick up. This has been cleaned out and apparently she pulls hard (I’ve not got her back yet), but still has the violent vibration, which is puzzling everyone. Spent many hours looking so far but not got any closer to finding the issue. Has anyone on here encountered this on their car? Or, have any suggestions as to what might be causing it?