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Well, as expected, the headwork did not do much with out bigger cams.
Pre headwork the car Dyno'ed at 207 whp with 138 torque...
We where using that as our main estimate base run.
The first base run after the headwork actually had the car at 200 whp 135 torque
Obviously with the faster flow a small loss in torque was expected...
So after messing with the V-AFC for about 45min run #7 gave us a peak of 210 whp and 133 torque.
We continued to mess with the fuel for about another 45 mins or so and kept fluctuation between 207 to 210...
At this point the car was pretty hot, so we stopped at pass #15 with 209 whp and 135 torque.
Nice and cold it should be at about 213-214 with about the same for torque.
I guess I know now that my next investment will be a set of cams to match up with the ported head and worked valvetrain.
anyhoo, here is the dyno sheet for pass #7 and #15
gotta give much thankx to Stephan at CarTech Tuning for letting us waste his Sat.
Wow, more compression and no power gain? Was it tuned with the VAFC for the pre-head numbers?
Go back and ask for the flow numbers on the head. More flow doesn't = more power for a given combination, but at a minimum it tells you that your porter knows something about what they are doing.
Originally posted by Leo Gets Basically what is happening is that the tighter springs are shutting the valves faster than OE, and since I don't have a bigger lobe on the cam to hold the duration that it is not doing much benefit.
Stiffer valve springs won't close the valves any faster than OEM springs, unless you are running at a higher RPM where OEM valve springs would allow the valves to float.
looks like you gained power across almost the entire RPM range 3500-9000. I think that is definitely a gain to be proud of. Who cares about peak, your peak now last longer and is over a broader RPM range. I give it a thumbs up!