hi folks im running a BAM engine on emerald ecu so dont use the vvt now having to rebuild my engine as think the rings have gone.. I'm running a standard recon K04 with uprated bearings and seals! and that was enough pull in my mk2 track car.. i was getting 270 bhp and 298 lb ft of torque.. so do i now change the head and get some gains but would what they be if there is any? wont be putting a big turbo on dont have much if any lag with K04 and as its my track car i want acceleration not to worried about top end!! also will have to run the small port inlet manifold as the way my boost pipes run i know i will have to port match it thats ok but will i lose any of the benefits of the bigger head this way? many thanks in advance for any help in this matter ! cheers Leigh
With the power you have the small head will flow enough, higher port velocity better for torque and spool in theory But in the real world I doubt you could notice any difference Although mismatched ports/manifolds could be something that does more damage than good
The AGU intake ports are actually worse for port velocity, so with a small eager little 5404 turbo, you would be doing yourself more harm than good for engine response on a track car. The "270" number you got at WOT would be the same on the so called 'big port' head. However this would happen at higher RPM than before and with loss in torque generally. So called BAM heads are only so because of the head stamping and the extra shims placed under the exhaust valve springs. They are the same as AMK, BFV, APX and APX engines.