I saw a few ads on Ebay.co.uk for TD/TDI/HDi dumpvalves kits which were basically a very expensive sliver box (housing a change over solinoid I believe) a micro switch, some wires a bit of tube a few fittings and a dumpvalve with T for around £300>. I decided to see if one could be done on the cheap using parts easily found in a scrap yard. A mate of mine had a bailey motorsport piston dumpvalve with a t-piece lying around his shed off a petrol turbo project so that was the start of the project. Firstly you need a source of vacume as a diesel doesent hve a throttle plate (well except on a ford transit diesel with EGR) simplest way is to use the vacume pump for the brake servo so using a check valve with two take off of an old 88 Golf 1.6 auto im braking I then had my vacume source. Now I needed a way of turning this vacume on and off when the throttle comes to rest. I found an EGR switch that fits on the LDA off a Passat TDI, and I also used an EGR solinoid off the same Passat. I fitted the LDA mounted EGR switch rigged it to a continuity meter and tested it by pressing and letting go of the accelerator and found it did the opposite of what I wanted, it closed the circuit when the throttle was pressed and opened it when the throttle was at rest. So I started wiring and plumbing in the dump valve using a change over relay as a "not gate" by using the normally closed (57a) terminal of the relay I once fitted I took it down the road to test it and found although when the the throttle returned to rest the dump valve would open as there was no boost in the pipe operating the dump valve it would be forced open by boost from the turbo resulting in a leak of boost. To rectify this I added a second EGR solinoid valve off a VW TDI that was tapped in to the manafold to LDA pipe and connected this to the normally open (57) terminal of the relay the used a T connector to connect the "Vacume" solinoid and the "Boost" solinoid to the dump valve. Once again I took it out on the road to test and found it worked, and cost me a few pounds in parts.
but we all know it'd be cool to be able to show off with a kapoosh kapoosh to keep everyone wondering,
Quote from: Trev0rbrbut we all know it'd be cool to be able to show off with a kapoosh kapoosh to keep everyone wondering, Actually, it wouldn't. It sounds really terrible and out of place on a diesel that does not need one.