I think i have a leak at the manifold , either in the gasket or manifold itself, sounds like its rasping? Not too sure if its inlet manifold or exhaust manifold but somethings blowing and main exhaust is intact. but i have looked at the supersprint design and its pretty much the same as a williams! apart from the exception that its stainless steel, so if i can get a williams manifold for £30 or so and get a few bhp (which is what renault did in the first place to get the valver to 150bhp) then id say sod blowing £400 on a supersprint one, get a williams manifold, and if you already have a williams manifold, get it ported and polished!