Can I use a VAFC to change CVTC??

04SerSpecV · Aug 30th, 2004, 09:32 PM

Hi all
My question is is there anyway to have that kick in before 5000rpm. Like does anyone make a controler for that ex: the A'PEXi V-TEC AFC II. If so please let me know also if not will there ever be one in the future?

Thanks
Preston

**chimmike** · Aug 30th, 2004, 09:52 PM

before I give you an answer, I want you to tell me what you think CVTC is and then tell me what VTEC is and tell me the differences............this way you'll answer your own question.

**chimmike** · Aug 30th, 2004, 09:56 PM

hint: if you don't know what CVTC stands for...check out www.nissandriven.com and find the Spec V there and read up on it..... or search for CVTC on the board here

pherschel · Aug 30th, 2004, 10:16 PM

Maybe he's refering to the secondary air pathway opening. I believe you mentioned that it makes no difference to open it early.

I have an 04 and i've listened for it opening. Maybe I was expecting a clunk or something, but I didn't really notice it. I expect its because of the increased engine noise and need to shift real soon that occupy me.

I do think the CVTC technology along with the variable intake, plus a lighter aluminum block make for an excellent combination. Just not to modder friendly.

And for those balance shafts, well my ford focus buddy (one for the wife, one for him) was impressed by how smooth the car ran.

Just my 2 cents

**chimmike** · Aug 30th, 2004, 10:23 PM

I just want him to understand exactly what CVTC is....I mean it tells you what it is on the tag on the side of the car when you buy it........that should answer his question before asking

Dwntyme · Aug 30th, 2004, 10:31 PM

I know, I know.....

**chimmike** · Aug 30th, 2004, 10:33 PM

well let's hear it.....please explain what CVTC is and why you could/couldn't use a VAFC!

04SerSpecV · Aug 30th, 2004, 10:34 PM

Continuously Variable Valve Timing Control System (CVTCS) Spec V
Variable Valve Timing and Lift Electronic Control (VTEC) Weedwacker

**chimmike** · Aug 30th, 2004, 10:39 PM

awesome

Do you know what VTEC does?

VTEC is a hydraulically actuated change of cam profiles from a lesser aggressive street grind to a highly aggressive cam grind. That's what the VTEC changeover point is.

CVTC is simply continuous variation of cam timing....from idle to redline. There's no different cam profile like on VTEC cars, so there's no changeover point. That loudness at 5400rpm is the secondary intake manifold runners opening up............and opening those earlier has shown power losses.

basically, if you were to use a VTEC controller (which you couldn't) you'd be robbing power from somewhere in the band to put somewhere else (lose low end to gain high end or vice-versa) The stock CVTC setup is great just how it is

Dwntyme · Aug 30th, 2004, 10:45 PM

dangit he beat me to it.... see what happens when your don't pay attention

tryptych · Sep 28th, 2004, 07:46 PM

the second det of butterfly valves in the short runners open at 5000 rpm, not 5400 rpm. But you can use the Apex AFC on the SER. Keep in mind that it will not control the variable intake or CVTC, of course, but it does modify the air/fuel ratio at different rpm's. The QR25DE tends to run quite rich at moderate to full throttle, and it has been shown that lightly leaning out the mixture made power gains as common with newer engines from almost all manufacturers. With several engine modifications done, one SER owner showed a gain of 22 hp on a dyno after tuning with the AFC from Apex. It's cheap too, only about $350 to $380.

**chimmike** · Sep 28th, 2004, 08:42 PM

nobody has seen 22hp from an SAFC....and the butterfly valves have been proven to open up at 5400rpm.

Beardog · Sep 29th, 2004, 02:37 PM

Quote:

Originally Posted by chimmike

nobody has seen 22hp from an SAFC....and the butterfly valves have been proven to open up at 5400rpm.

....22hp??? NOT!

Dont argue with the master ( aka chimmike )

**chimmike** · Sep 29th, 2004, 02:40 PM

12hp I can fathom. but 22? no way in hell, unless you failed to mention he was running 400cc injectors untuned, LOL

BlackoutSpecV · Sep 29th, 2004, 02:51 PM

Quote:

Originally Posted by tryptych

one SER owner showed a gain of 22 hp on a dyno after tuning with the AFC from Apex.

with a turbo, maybe.