Low to Hi Cam Angle @ VTEC (From 30 to 50 degrees @ 3000rpm)

[joejoe3]

I got a question to ask...

Well for those who are fimilar with cam angle tuning, it takes 0.1 second to rotate 10 degrees physically. My VTEC point is set at 3000rpm, which was dyno tested to be the most suitable for my supercharging setup.

At the dyno, we tested 30 degrees in low cam made best power, while 50 degrees in high cam made the best power. After my tuner has completed the tune, I took a look at the dyno graph and the calibration when I got home.

I noticed that my tuner, instead of starting to change the cam angle at the low cam map from 30 to 50, he did that on the high cam map instead... so that may explain a significant dip in the dyno graph from 3000rpm to 5500rpm.

Becuase of where the VTEC crossover set at 3000rpm, I can only start rotating the cam angles from 30 to 50 degrees in the low cam map starting at 2000, 2250, 2500, 2750 to 3000rpm.

The question is, I'm not quite sure if there's enough time for the cams to rotate 20 degrees in 1000rpm worth of time (*I know gearing will play a factor, but let's assume 3rd gear pull which is about 2 seconds or so)...

Should I make the change and have it start rotating at the low cam instead or the high cam?

Example:
LOW CAM MAP (Wide open throttle):
2000 and below - 30 degrees
2000rpm - 30 degrees
2250rpm - 35 degrees
2500rpm - 40 degrees
2750rpm - 45 degrees
3000rpm - 50 degrees

HIGH CAM MAP
3000+ rpm - 50 degrees

thanks!

[joejoe3]

I posted the current one in my kpro now, and one that i moved the cam changes to the low cam table instead.

Please check to see if it's within reason for cam adjustment from 30 degrees to 50 degrees from 2000 rpm to 3000 rpm

[joejoe3]

Dyno break down...



As you can see, the transition at high cam from 30 to 50 created a power loss... it's noticable when you look at the power curve once the cam angle got to 50 degrees on the high cam.

[joejoe3]

hondata?

[El Verdugo]

On the Low cam I see that its a bit choppy on the HP/TQ lines, is this a bit of misfire or what? How does the car feel when it actually revs up from the low cams to the high?

Thanks in advance,
Alberto

[bubble_brain]

wouldn't it be better to set cam advance a little less in lower rpm's?
for example.

low cam map
2000 & below- 20 degrees
2500- 30 degrees
3000- 40 degrees


high cam map
3500- 50 degrees

this way cam angle would be fully at 50 degrees at a little after the low cam to high cam map change.

hmm... or maybe not. im just learning myself.