Late torque

[herald]

Easy access to Audi original diagnostics and a compressor that happily powers a 13 bay workshop! Sounds like I'll need to hand it to someone that knows what to do to check for boost leaks comprehensively.

I googled Hyperboost DV and the first picture that comes up looks exactly like the one in the car, so I suspect it is still there. Is that good or not?

[twoqu]

I would think its worthy of investigation as it fits with our "its on the car" hypothesis! It should be open on the over run and shut under boost. Unless you like bling, there is no reason to run anything other than the popular 710N version. Without seing its orientation its difficult to comment. These are often plumbed in backwards as some people claim advantages over the way it was designed to operate.
Not familar with this DV. If there are issues with it then I guess it would be common knowledge on the internet.

[twoqu]

Is it like this?

http://www.audiworld.com/tech/eng85.shtml

[herald]

Good thank you, I'll go down that route as well as the leaks route. The car is a daily use machine, underbonnet looks are irrelevant, it's how it drives that is important for me.

[twoqu]

Got to be worth checking its not getting stuck open. If it was that might explain things. So you can either clean/lubricate/check operation or subsitute. If it was open until a certain amount of boost pressure eventually closed it that could account for the behaviour. There is some discussion about the correct way to orientate it. Some say that the flow from the turbo should enter the side and come out the bottom whilst some say that the other way round is better even thought that is subjecting the bottom of the piston to boost pressure! The Audi fitment is side in bottom out.