I was just wondering if people are dynoing there engines through the rev range (well over where boost is up) on both sets of lobes...

I was just thinking that an early engagement under pressure might yield BIG gains over keeping it at the stock crossover.

If I'm going over something basic sorry... flame me.

 

thats what hondata tells you to do when you dyno. run the low cam , then the high cam, and when the low stops makin power and the high starts , make that your crossover point.
-jonathan

 

It all depends on your tuning set-up.
My tuner has delt with a few v-afc hacks, and his experience (and mine) has been that if you move the switch-over up in the rpm band it created a smooter transition.
Example....with the cross over set at 5,200 (about stock) there is a dip in power when it switches over. Sometimes a dip as much as 20hp.
I had lost about 14 hp at my cross-over (stock setting) until i moved it up to about 6k rpm. I lost no power at the cross-over and it created a smoot tranistion.
If you can run it on low cams and high cams only then make the switch where the two intersect (low stops making power and high starts making goos power) then thats probably your best bet.
But it seems that most people who run the v-afc hack beinfit from moving the cross-over up about 400-600rpm instead of lowering it.

 

Your NA though right... *edit* OHH I just read your sig.... your LOOSING hp by making it earlier... How much boost are you running and when does it spootl up?? */edit*

I meant for turbo... the turbo should be PUSHING the same if not more air at say 3-4k then the engine would be PULLING in at 6k NA.

The first guy answered my Q though... I figured it was realatively standard.

 

I'm runing .65 bar.
My crossover is set at 6k rpm.
By moving it up i mean later not up as in lower rpm.
I'm at full boost by about 5k rpm..
And yes making it earlier (setting it at say 4k rpm) will cause a loss in hp

 

Just try to make sure your engagement point is not the same as the RPM at which you make full boost. That info is from MatT3T4. Not sure where he is these days, but hope he is doing ok.