VTEC crossover.....

[SPEEDCORE]

Wanting people's feedback on Vtec crossover specific to B16A.

Personally I am not in favour at all for adjusting the crossover point with an internally stock engine.

In the case of a B16A2 (EK4) with I/H/E and PFC to tune.... would those of you that tune actually change the VTEC crossover at all... and if you did would it be so dramatic that you would set it at 6k rpm?

I am at a loss to understand why it was set so flippin high....

[ProECU]

hmm, 6K might not be too far.
Did you know the stock x-over point is 5800 for low load and 5300 for high load?

Depending on the setup & tune, the low cam configuration may make power this high.

It does seem a bit strange though, ive never set x-over this high on any of the B16's ive tuned

[SPEEDCORE]

So would you say that it would be wiser to just set it to the average of 5.5k?

I'm used to high cam comming in at 5.5 and just find it strange that just simple I/H/E would warrant the x-over to be set at 6k.

Another thing I am thinking is that the PFC is B16B specific..... so I'm thinking could it be that the tuner accidently just left it at the x-over of 6krpm (CTR is 6k x-over yer?)


Just out of curiosity... how would you go about doing a low cam run then a high cam run so you could see where the two crossover to determine an optimum crossover point.

[pgclee]

6k rpm is not high...i had mind at 7200rpm...hehe...

[SPEEDCORE]

6k rpm is not high...i had mind at 7200rpm...hehe...

Stock engine? More specifically cams?

[weezer]

6k rpm is not high...i had mind at 7200rpm...hehe...

Mine is set that high also

[spoondc2]

6k rpm is not high...i had mind at 7200rpm...hehe...

You must having a crazy camshaft......

[spoondc2]

Wanting people's feedback on Vtec crossover specific to B16A.

Personally I am not in favour at all for adjusting the crossover point with an internally stock engine.

In the case of a B16A2 (EK4) with I/H/E and PFC to tune.... would those of you that tune actually change the VTEC crossover at all... and if you did would it be so dramatic that you would set it at 6k rpm?

I am at a loss to understand why it was set so flippin high....

I just heard about how ppl set their crossover point, they do 2 runs with 3000rpm vtec and 7xxxrpm vtec and try to find out the crossover point when the torque curve drops. Normally it's around 5000-5500rpm for stock cam.

[ProECU]

OK
the story is the vehicle is tuned on both low cam only and again repeated for Vtec cam only.
Where the two torque curves intersect is the theoretical vtec x-over point.

All you guys who have 7k+ x-over are losing power.
I guarantee you the vtec lobe is making more power than the low lobe at that rpm.

Think about it, you only have an extra 1000rpm before redline, so whats the point of a 7200 rpm x-over?

[ProECU]

Mine is set that high also

hehe, yeah, well when you rev to 10k, with C cams, its a different story, LOL

Good one Vinh!

[panda[cRx]]

Mine is set that high also

who asked u toda boy?

[VT3C]

hmm, 6K might not be too far.
Did you know the stock x-over point is 5800 for low load and 5300 for high load?

Depending on the setup & tune, the low cam configuration may make power this high.

It does seem a bit strange though, ive never set x-over this high on any of the B16's ive tuned

My JDM B16A (2) ALWAYS switches over at 5800.. Low load or full load..
I find that the non-VTEC cam profile is still pulling hard when it hits 5799 however there is a good kick and noticable power spike on the RSM dyno graph thinghy when VTEC does engage. I think that whilst it FEELS like the non-VTEC cam is still gaining power, it is truely at it's peak power right as it switches profiles into VTEC.

co-incidentally, my VTEC switch point at 5800 is VERY, VERY pronounced in relation to the change in audible engine note (the VTEC 'noise').. VTEC set lower on other B16A's i've seen is not as audible.. but that means absolutely nothing.. but it sounds nice and makes non-VTEC'ers look accross with the WTF look hahah.