majdi

Hi, is that true some car open vtec 2 time, i look at b18c last night, the sound look like vtec engage 2 time. It is possible using crome advance vtec switchover or Plugin - control - Control Advance Vtec setup P28,P30,P72 to make vtec open 2 time.

HRTuning

B18C has something called Intake Air Butterflies. It's not VTEC kicking in twice.

0mtber

iTrader: (2)

I have my vtec kick in 6 times each pass on my 8 second integra using crome :-)... Just kidding.

As JR stated, the b18c1 engine has ONE vtec lobe, hence vtec is at one activation point.
The intake air butterfly system (IAB) is on the stock b18c1 engine & h22 engines. This is an output which will open the runners in the stock manifold at a specified rpm.

majdi

How about b16b? it also got same sound, vtec engage about 5.2k and sec is around 6k. i cannot see what modification he do, since he don want show the engine for us..

majdi

Hm..maybe i heard wrong sound, anyway can b16 engine add IAB system, and chipped ecu that have IAB control?

bigD

you may want to do some more reading on how vtec and IAB work, I dont know why you would want to add them to a b16.

GhostAccord

May also what to do some more reading on how VTEC works. IIRC once VTEC is engaged it stays engaged until your drop back down below the engagement parameters.

majdi

Yeah i will , reading searching and looking in youtube bout vtec and IAB work. Thank for the hint. And I'm dont want to add IAB to b16, I just want to know why b16 sound like 2 vtec engagement, is there possible they put Iab system to b16 engine. I think maybe i got wrong hearing or that car vtec system is broken..hm * Start reading!!!

GhostAccord

That could also have to do with the design of the engine components. For example, my F22B2 non VTEC sounded like it had VTEC @ around 3800-4200 RPM. That was after I added 255cc injectors, headers, ported intake manifold and a short ram intake. I am going to assume that that was where everything clicked together and there was a power band change. Never had it on a dyno so I cannot confirm actual power gains, this was just an ear and butt dyno assumption. Not just mine ether

majdi

so that explain me a lot, hm it maybe not a vtec open 2 time at all..


Looking into old thread, https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/difference-between-vtec-switchover-vtec-engagement-2632906/
Correct me if wrong, Low Cam table run when vtec Off, and High Cam table run when vtec On. And what used for < C R O M E > advance table - vtec switchover since there have table to adjust Low Load [Engage/Disangage] and High Load [Engage/Disangage] it is different thing between Low cam @ Low load / High cam @ High load? here i attach the picture.

0mtber

iTrader: (2)

There would be no point in using IABs on a b16 engine with a b16 intake manifold.
You are digging a whole to nowhere.

0HAMOTORSPORTS

This is not VTEC engaging twice. The picture shows CROME'S 'attempt' at variable engine load (ie: map values) to allow VTEC to engage slightly earlier or later dependent on engine load...

Disengagement RPM is exactly that: what rpm at which VTEC will disengage and allow the rockers to return to the low speed cam lobes.

The only engines that have "two stages of VTEC" are certain JDM D series engine from 96-00 IIRC

majdi

Thanks HAMOTORSPORTS, now i know what mean switchover, some reading explain "set vtec 3000RPM and run on dyno, then set vtec 6000rpm and run on dyno, overlap the two graph and where ever the torque curves meet/cross is your vtec point."

So no such thing vtec open twice except D series engine 96-00 IIRC like you said. There lot of local chip seller lie on vtec open twice in the internet..so i will not get cheat with all answer in here. Thanks


http://causeforalarm.thecarthing.com...TEC/index.html

0mtber

iTrader: (2)

You really can make vtec kick in more then once with a custom set of timer delayed switches & relays.... LOL just kidding.

majdi

Is that can be done I WILL hahaha