Thread: Replacing turbo boost regulator hoses results TD5 Discovery 2

Last night I changed the hoses on the turbo boost regulator. I changed them from what appeared to be 1/4" vacuum hoses to 5/16 high pressure fuel line (I assume high pressure SAE30 rated and 5 Bar), I used hose clamps to hole them in place but they were not what I would describe as too loose (except for maybe the bottom connection on the boost regulator). I also squirted degreaser through the regulator to clean it. (Do this when the hoses are not connected to avoid filling your intercooler with degreaser, the engine doesn't like degreaser mixed with its air)

The result is amazing. I've cleaned the regulator before and noticed a small difference, but changing the hoses has made a huge difference to how fast and smooth it comes on boost and how smooth the gear changes are at full engine load, no hesitation or boost blip for lack of a better way of describing it.

Just thought I'd mention it in case others might want to try it, it's not an expensive or difficult thing to try. If your car just doesn't seem quite right or lacks the smoothness it once had this may be your fix. I'd also suggest cleaning the MAP sensor located on top of the intake manifold too.

Originally Posted by twr7cx

When I used to play with turbo charged petrol cars it was always recommended to use large hoses for boost lines (e.g. boost gauge, waste gate, controller, etc.) as they claimed the reaction was more responsive and accurate. Perhaps this is what you have experiences with the slight size increase? Or perhaps the stronger side walls are the cause of the improvement.

I think it's partly the sidewall strength.

I had similar improvements in responsiveness when I switched from vacuum hose to a LR replacement part.
The stock part is a high temp rated pressure hose.

Vacuum hose is designed to deal with relatively low temperatures and suction forces.
It stands to reason that the high heat will soften the vacuum tube and the boost pressure will cause it expand.