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. :confused:

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...

:confused:
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...... :rolleyes:

[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? :p

[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.

[ProECU]

My JDM B16A (2) ALWAYS switches over at 5800.. Low load or full load...

This cant be true. Hook up a test light in cabin and check it this way.
You'll see what i'm talking about.
Ive datalogged this many times also, so it is true. Low load & high load are in fact different.
There is also usually a discrepancy between actual activation & cluster rpm's!


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.

This sensation is because honda typically run the x-over point quite rich.
The Butt-dyno will sence power at this point becuase the transition between rich to lean will always generate HP.


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.

hehe, vtec rocks!

[pgclee]

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?

mine goes 10k++++++...hehe...so i got another 3000rpm+++++ to play with...hehehe..but the problem is...i don't know how to get more power...any suggestion? hmmm.....but it's irritating to know that you won't get over 140kw+++ atw if you are not using race fuel with race settings....why those Hi Rons does so much on the power?..haih...

[pgclee]

:confused:
Stock engine? More specifically cams?


yea..Stock engine...By Toda...hehehehe...it's still stock rite...hehehe...

[TODA AU]

mine goes 10k++++++...hehe...so i got another 3000rpm+++++ to play with...hehehe..but the problem is...i don't know how to get more power...any suggestion? hmmm.....but it's irritating to know that you won't get over 140kw+++ atw if you are not using race fuel with race settings....why those Hi Rons does so much on the power?..haih...

LOL... That's not really true at all.
Your power target isn't impossible, just not cheap where you're at.

Honestly, you need to have your car built & tuned by someone who actually knows what they're doing... Not some tool pretending to know.
Unfortunatly, that's going to cost you.
The most expensive thing is going to be finding then un-building the f#%k-ups already build into your car.

High RON fuel often makes more power for retarded tuners because it lets get away with the stupid timing figures they were already using.

[SPEEDCORE]

Thanks for the help guys..... discussions about 10k rpm and toda internals is really gonna help me out.

Be sure to tune in to a thread I will start specifically for you guys so you can pull your own cocks over and stroke your ego's some more.

Thanks to those that genuinely helped..... you know who you are.

Mods please close thread as I'll go else where to find technical help.

[wynode]

SPEEDCORE, i'm assuming you didn't get the answer you were looking for (I can't read your tone from your last post).

I'll leave this open incase someone has anything PRODUCTIVE to say. pgglee, thats great your car revs to 10K but its not helping us here so please make another thread if you want.

[pgclee]

thanx adrian...
but it seems like there is no one i can trust in melbourne to do that kinda things that i've wanted...and i am so lazy to go to your place cause is so far..hehe..if you ever come down to Melbourne, i think lots of honda's will come to you...all i can say is that...all those ignition timing + cam phasing can do alot more power but there is no one who knows what they are doing when i told them to "try different setting"...

It's hard to find a good builder yet is even harder to find a good tuner...

[KB]

OMG I Just Can't stop thinking about cheap tyres!

[pgclee]

OMG I Just Can't stop thinking about cheap tyres!


What tha....??

[BLKCRX]

thanx adrian...
but it seems like there is no one i can trust in melbourne to do that kinda things that i've wanted......

Keep looking were out there... ;-)

[pgclee]

keep looking? Haha...then how much will they charge me? 1.5k - 2k?...for that price i can give my friend a ticket to fly over from Singapore or malaysia and do it for me...

no offence, but seriously i have no idea who is good here....if they are good, yea, Good in TALKING...when come to technical, they don't know anything...

[BLKCRX]

keep looking? Haha...then how much will they charge me? 1.5k - 2k?...for that price i can give my friend a ticket to fly over from Singapore or malaysia and do it for me...

no offence, but seriously i have no idea who is good here....if they are good, yea, Good in TALKING...when come to technical, they don't know anything...

what kind of technical help ? thats where I specialize in, especially in Honda's and always stride to explain everything I do just ask anyone I deal with directly ;-)



2k to tune a car thats a bit rich .. but again depends what is being tuned, and how.



Regards James

[panda[cRx]]

knowing pgclee it means high rpm.... just like 2TEASE that died shortly after tuning:rolleyes:

[pgclee]

I've organise smth with Motec tuner, Daniel, let him have the say then see how things goes...

[wynode]

pgclee, I'll say it again.....this thread is not about tuning YOUR car. Read the first post and then look at your replies.

You have a warning PM.

[spardikis]

With stock internals....leave the factory x over point otherwise with B/C spec cams....Get it tuned properly on the dyno

[Non Vtec]

If you get it tuned on a dyno, set the vtec at 7000rpm and see what power it makes then set the vtec at 3000rpm and see where the 2 lines would cross and set your vtec there.