Aside from going on a rolling road, which from what I gather are sometimes inaccurate, and i'll never get round to it anyway, can someone geusstimate the BHP for my car:
Cav Gsi with Coscast head.
Janspeed 4-2-1 manifold and full Janspeed system inc decat traight thru pipe, and backbox.
Drilled airbox and extra hole in engine side which is filled with a fat pipe running straight to the grill, plus resonator thing removed.
K&N panel filter.
Throttle body wedge removed.
cam breather mod carried out.
Engine is in excellent condition, with oil always changed throughout its 114k around every 3-4k - checked all history/receipts etc.
New NGK triple prong plugs, dizzy and rotor also new, Beru leads from old Gsi which had 75k - so running damn near perfect.
Was rolling roaded by previous owner, before any of above mods at all done (i.e. dead standard), and showed 128 Bhp at wheels, estimated at 151 BHP.
Just interested to know how accurate my guess is - it does seem very quick for a heavy Cav when comparing to the old astra Gsi, which was very quick.