does anyone know where to get a gm ebv from as heard they are really good

I am sure you could get one from a Vauxhall dealership. However I am not sure what Vauxhall/Opel cars it would have been fitted to, and the part number.

I am sure someone else will come along and answer that.

hopefully, want to try and get one before the rolling road in a couple of weeks

There was another one that is often used called a perrin.

http://www.perrinperformance.com/products/show/64/Boost-Control-Solenoid?category=37

I would have said the Perrin is the one to go for

Search for "RockAuto"

cheers guys, had a search through the forum and found the part numbers, is the gm one just as good as the perrin, it seems to cost about half as much as the perrin, i am only looking to put a gtec 1 in so would want it hold up to 1.2 bar, anyone any experience in using either

People have posted up comparison graphs of all 3 EBVs before (standard, GM, and Perrin), a bit of searching should dig them up...

had a look through seem to be good reports on both, couldnt find any graphs for the perrin, but lot of folk seem to like them, the gm ebv is about half the price but has to be shipped over from the states and the rolling road is a week on sat so might be pushing it to get it delivered in time

RockAuto is really fast. I ordered one GM EBV and got it within a week

Here you can see the difference between Pierburg EBV, GM EBV and Armval PRV:
Boost comparison

All parts have been tested on my car.
The Pierburg is tested with a Gtec 1.
GM EBV and Armval PRV is tested with Gtec2.

cheers freddan, how does it run on yours, it certainly looks a lot more stable than the stock ebv

Sometime I can see small fluctuation, but we are talking about 0.1 bar here and that is nothing compared to Pierburg´s 0.5 bar.