Hiya matey,

MBC, is that a manual boost controller? When i first got my car it had a manual type boost 'controller' and it did similar things to yours, peaked at 21 and dropped to 16-17.

With an electronic boost controller like a gizzmo IBC it will hold 20 with a peak of 22ish. At the moment my gain is too high to i peak at 25 and drop to 20, but tbh i think its partly because i've reached the limits of my turbo.

I'll PM you a later on mate about things.

Rob,