Quote:
Originally Posted by mydreamcar
So how much to do the heads and what kind of power would we see, low side
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That can range ALOT! You have a company such as CFM that will port our head with angle valve job starting at $1000. I heard matt D, the one who ported and did the valve job for bmwdon and now installed on gretchen's car charge $1000 for the head and intake manifold for a complete job. So you are looking at around $3300, maybe a little less or a little more for install/head/cams.
Gain on the low side probably will be around 30-40 to the rear for the combo
but if I had to guess I would say around 60 and maybe more depending on the grind for the combo. We just won't know for sure though until someone actually dyno the head but according to the flow report on matt d's worked head it could be possible that we could see 40+ with just head alone.
This is all from when bmwdon was doing the heads back in 2010. Maybe he can chime in and give us more info.
This is stock head's flow
"Intake
.200 135
.300 152
.400 160
.450 162
.500 160
Exhaust
.200 135
.300 152
.400 160
.450 162
.500 164
After the work
"Intake. Gain over stock
.200 195 +7
.300 262 +7
.400 304 +29
.450 324 +43
.500 327 +43
.550 334
.600 339
exhaust
.200 147 +10
.300 175 +23
.400 194 +34
.450 200 +38
.500 203 +39
.550 205
.600 206