Will you take the old manifolds in part/ex ?!! Probably not ! Any ideas on pricing and likely power gains - 10% ?
I'd like 10-15% gains, we shall see.... Much of my design work on these has been empirically based, because I really don't know how to tune/design exhaust lengths to a valvetronic (variable valve opening duration and lift) engine. So I've crunched the numbers I can and come up with something that should give good gains around peak torque and also breath far better than the standard (and frankly horrible) BMW manifolds.
They may not make production, they may not work, so no, I don't know real world prices currently, they are an awful lot of work, and there's a lot of material cost in them. Not to mention the cost/work in stripping out the old manifolds...
Simon @ SiFab.co.uk
