I appreciate your feedback each to their own opinion but I was told I helps preserve the life of the turbo ans if im honest I like the sound. I dont have a normal lucida. It is kitted and tinted and all I was after was a bit of advise on tyres really. Just thought I would ask as I have seen them with dump valves on.

Even if you found a way to operate the dump valve, you'll just creaate unnecessary turbo lag-and look foolish!

If he drives a fully kitted out Toyota Estima Lucida I don't honestly think he will to be worried about looking foolish (or more foolish).

The air intake on a diesel is not throttled. Power is controlled by varying the fuel delivery rate. Hence there is no excess boost to dump.

The tyres you mention will significantly increase the rolling radius and thus you will end up with the speedo under reading wildly - which would be illegal and unwise given the presence of speed scameras. You need to find tyres with the same radius. 235/70/15s might do it, but the 15 inch rims may not fit over your brakes.

Hi I think the idea was fitting it to the wastegate. So yes probably ppretty pointless but like I said if im honest I like the sound. I know alot of people dont like them think they sound silly and people look silly driving them but thats their opinion and im not fussed.

On the other hand with the tyres I may just stick with what I haveif it might effect my insurance. Thankyou for the advice. I just aassumed all terrain tyres would give better grip and living on a bit of a muddy slope thought it would just make it less work for the van. Thanks again