Vtec: Factory settings vs Vtec control

[vtec.]

Hey,

I bought my Prelude VTIR recently and it came with a APEXI unit already tuned.

The Apexi neo has a vtec control feature, which had been set to lower RPM. This seemed to create a linear power curve which I found to be fairly responsive and while the VTEC is weak - I didnt have to wait all day for it.

I've recently tried changing back to factory setting in order to compare, found that I got a non-linear curve of power - so at high RPM excellent VTEC kick, but have to wait for it.

I think when I compare them it's basically the same amount of power and response- just different delivery [linear or non linear curve]

Is this accurate?

Basically I guess it depends on what sort of power you'd prefer... I'm leaning towards the factory setting because the high RPM VTEC feels strong and fast.

[JUST VTEC]

Im guessing theres a reason when hondas get tuned they usually lower the vtec engagment rpm ,not saying this is the case .but with proper tune your fuel and air are altered aswell as the vtec engagment point .But from what i know a vtec controller itself has a negative effect on the car because its factory tuned in a set way .but i could be wrong ;) Iv always prefered a linear power curve to a high Rpm kick.

[curtis265]

uh oh

ahve you seen the power curves?

you can't know without a dyno.






What he'd done is have it dynoed on low cams, and then dyno'd on high cams.. The idea vtec point is where the two lines cross obviously. By moving the vtec higher, you're essentially choking the engine past that ideal point, then suddenly releasing it.. So you're actually going slower than what you actually could - do i make sense?

[eren]

http://img.oo.com.au/prod/TYVT91483/1b.jpg
:3

[JDM DC2R]

My cars tuned with a apexi neo!. Theres the dyno paper! vtecs lowered by 800rpm. Power curves alot better!

[curtis265]

There we go. Notice jdm dc2r's dip in torque before vtec... The h22 has a similar dip which you are trying to get rid of



http://img.oo.com.au/prod/TYVT91483/1b.jpg
:3

Tempted to neg...

[PHO]

My cars tuned with a apexi neo!. Theres the dyno paper! vtecs lowered by 800rpm. Power curves alot better!

Hnnnng, tuned by adrian. You lucky lucky guy.

[JDM DC2R]

The Force was stong in him. LOL.. Yer his a great tuner! Alot of poeple were spectacle. And some places refused to tune the apexi neo, when i was getting prices. He got a great curve, great max power. And after the tune ive run in the 13.8s on the quarter a couple of times

[curtis265]

The Force was stong in him. LOL.. Yer his a great tuner! Alot of poeple were spectacle. And some places refused to tune the apexi neo, when i was getting prices. He got a great curve, great max power. And after the tune ive run in the 13.8s on the quarter a couple of times
shit, good job bor

[JDM DC2R]

Couple of vids below. If your going to mess with the setting. Right down all the stuff on to your manual section Setting notes page 42. So you can always change them back, if you stuff it up or so.


http://www.youtube.com/watch?v=MXHQ6MQs_AI

http://www.youtube.com/watch?v=pzwCImHHIig

[DreadAngel]

What else is done though?

Altering the VTEC point I would think is similar to using adjustable cam gears on stock cams. You might gain a little bit but lose something in return. Usually more to lose than gain.

[JDM DC2R]

Light wheels, I/H/E hasport mounts.

At 5800 rpm theres a 15 kws increase. Easy the tune had the biggest benefit over all the other mods.

He said the unit is controlling the vtec and is tuned. So i wouldnt touch it

[curtis265]

Btw im quite sure it has been dyno tune, so i dont think your butt dyno will do a better job

[vtec.]

Thanks for the info everyone :)

[mocchi]

np man glad i helped.

[Super-DA9]

I know I've said it in many other threads, but I feel the need to say it again here.

The VTEC (secondary cam lobe) engagement point isn't something that you want as early (or as late) as possible. You won't (necessarily) get more power by making it kick in earlier. Ideally what you would want is to have is a very smooth power curve, by having it engage right where the primary cam lobes begin to run out of puff, or if you looked at a dyno graph with vtec disabled, it would be right where the line starts to drop.

When to set the engagement point will vary depending on your cams and cam timing. But when the vehicle is stock, the engagement point is already set in the correct place and should not be changed until you mod your engine in a way that changes its internal characteristics. By this I mean cams or timing, with the only exception (external mod) being changing to a single stage manifold on a B18C2 (DC2 VTiR).

[Daveho1]

yeah what tim said!

[GU357]

What else is done though?

Altering the VTEC point I would think is similar to using adjustable cam gears on stock cams. You might gain a little bit but lose something in return. Usually more to lose than gain.

that would merely adjust the timing so that it might be more accurate at higher revs but be open too soon at low revs causing torque loss since the combustion power would travel right up the valve instead of push the piston, would be good for anti lag on turbo.

but as standard for some reason it seems that the B series seem to have a pre Vtec dip. that once tuned out is better

[curtis265]

that would merely adjust the timing so that it might be more accurate at higher revs but be open too soon at low revs causing torque loss since the combustion power would travel right up the valve instead of push the piston, would be good for anti lag on turbo.

but as standard for some reason it seems that the B series seem to have a pre Vtec dip. that once tuned out is better
B/H series need some vtc love..

[vtec.]

Today I was having another look at the vtec control settings and found that I can easily switch between factory setting and the modified lower rpm setting. So luckily I didnt lose the modified setting because I'm fairly sure the numbers should be precise.

[migoreng]

Hey nick. You gain 10kw at 5000rpm and 5kw at 7000rpm with the tune.

You won't lose the settings unless you initialize it. I still have the settings. The air to fuel ratio is about 12.7 all the way to red line.

Overtaking becomes easier due to the extra midrange power.

http://i237.photobucket.com/albums/ff47/migoreng1/IMAG0190.jpg

When my engine was stock with ~180,000km I believe that dyno was over reading as stock 5th gens should run 100kw at the wheels stock.

Notice the difference in power curves.
http://i237.photobucket.com/albums/ff47/migoreng1/dyno/dyno.jpg

Getting the tune from Adrian at Toda 2 years ago.

http://i237.photobucket.com/albums/ff47/migoreng1/dyno/DSC01693Large.jpg
http://i237.photobucket.com/albums/ff47/migoreng1/dyno/DSC01696LargeMedium.jpg
http://i237.photobucket.com/albums/ff47/migoreng1/dyno/DSC01697.jpg

[connorling]

apexi afc neo only change the vtec point, but it doesnt automatically adjust the fuel or ignition to suit.
most of the time you will lost power without actually tune it.

hondata changes the vtec point and ignition fuel to suit by itself.

if you want to be serious about it, get a hondata.
afc neo can only get you so far.

hondata or power FC opens up a lot more.

[curtis265]

apexi afc neo only change the vtec point, but it doesnt automatically adjust the fuel or ignition to suit.
most of the time you will lost power without actually tune it.

hondata changes the vtec point and ignition fuel to suit by itself.

if you want to be serious about it, get a hondata.
afc neo can only get you so far.

hondata or power FC opens up a lot more.

it's had it's AFR and vtec point tuned on the dyno, best leave it be.

[JDM DC2R]

apexi afc neo only change the vtec point, but it doesnt automatically adjust the fuel or ignition to suit.
most of the time you will lost power without actually tune it.

hondata changes the vtec point and ignition fuel to suit by itself.

if you want to be serious about it, get a hondata.
afc neo can only get you so far.

hondata or power FC opens up a lot more.

Im some what disagree. If your not plaining to do internal work inside the engine. just simple I,H,E why not tune,adjust vtec with a apexi. I got both great result on the dyno and on the drag strip!

[DreadAngel]

I think you're missing his point...

He said if you want to be serious, which I would take as cracking open the engine and doing all sorts of crazy shit then a Standalone is the way to go.

Piggyback are perfect for the your application like you said though =)

[curtis265]

I think the cost to benefit is roughtly similar.. it's just to do with what you can afford/justify spending now.

[Chernoby1]

One of the benefits of having the 'smaller' profile active for longer is lower fuel consumption, and my crossover is pretty high for this reason (crosses ~6000rpm).
I don't know about you guys, but im not often at full throttle under 6000rpm, or should i say im hardly ever at full throttle if not on the 'bigger' lobe :)

Also if you're being serious get a standalone. The hondata is good for a lot of situation, especially those where you want to change fuel/ignition maps but that's about it. If you're looking into direct ignition / alpha-n maps and other 'fancy' things then you've gotta go standalone.

[curtis265]

One of the benefits of having the 'smaller' profile active for longer is lower fuel consumption, and my crossover is pretty high for this reason (crosses ~6000rpm).
I don't know about you guys, but im not often at full throttle under 6000rpm, or should i say im hardly ever at full throttle if not on the 'bigger' lobe :)

Also if you're being serious get a standalone. The hondata is good for a lot of situation, especially those where you want to change fuel/ignition maps but that's about it. If you're looking into direct ignition / alpha-n maps and other 'fancy' things then you've gotta go standalone.

if you're not flooring it i don't see a reason why it'd get to 6000 rpm...?

heck, even 4000

[PHO]

if you're not flooring it i don't see a reason why it'd get to 6000 rpm...?

heck, even 4000

5.1 budday

[Chernoby1]

if you're not flooring it i don't see a reason why it'd get to 6000 rpm...?

heck, even 4000

50% will get me to like 5k. What I really meant to say is that I dont often go between lobes; once above 6k, it stays above 6k for a while lol ;)

[JDM DC2R]

im always shifting at 4800 rpm. Just before vtec. and its the only way to get the car moving!

[curtis265]

wth guys.. i shift at 3k, and 2.5k if i'm going slowly.

what's the point of using 50% throttle and revving it so high for?

[EKVTIR-T]

wth guys.. i shift at 3k, and 2.5k if i'm going slowly.

what's the point of using 50% throttle and revving it so high for?
they probably have smaller engines and need more push them in car

[PHO]

wth guys.. i shift at 3k, and 2.5k if i'm going slowly.

what's the point of using 50% throttle and revving it so high for?

i shift at 3. 75% throttle the whole way






















http://www.ozhonda.com/forum/customavatars/avatar38865_4.gif

[JDM DC2R]

wth guys.. i shift at 3k, and 2.5k if i'm going slowly.

what's the point of using 50% throttle and revving it so high for?

More like 30% throttle. B18c7 and my apexi unit tell you % throttle im on! Why i like to get moving.

[curtis265]

they probably have smaller engines and need more push them in car

oh yeah i forgot lol


no talk

[mocchi]

101% throttle all the time bro.

go hard or go home

http://www.ozhonda.com/forum/customavatars/avatar38865_4.gif

[Chernoby1]

101% throttle all the time bro.

go hard or go home

http://www.ozhonda.com/forum/customavatars/avatar38865_4.gif

*recalibrates tps to get that extra 1%*

[Vvvtec]

tps high voltage cel



















http://www.ozhonda.com/forum/customavatars/avatar38865_4.gif

[Chernoby1]

Easy fix, take out cel bulb.

[RenzokukenJ]

101% throttle all the time bro.

go hard or go home

http://www.ozhonda.com/forum/customavatars/avatar38865_4.gif

http://www.ozhonda.com/forum/customavatars/avatar11984_24.gif

[vtec.]

Thanks for the info Jason.

[u mad?]

5.1 budday
yeahh budaayyyyyy

brb 4.5 k on highway

[PHO]

yeahh budaayyyyyy

brb 4.5 k on highway

Big lobe just sitting there ready for ya cruisin at 100. Haha