vvti

[Ascendant Rice]

im just understanding how vvti works not too sure how dual vvti works but i imagagin it sthe same except that teh exhaust is also variable.

i notice vvti kick in around 4k rpms on my rolla which kinda sucks casue if i drive normally i never get that high in the rev range due to the auto tranny, although having said that my ecu has learnt to shift more around 5k rpm.

so when does your vvti kick in? how noticible is it?

[DJKOR]

Yes, dual VVT-i means that both the intake and exhaust camshafts are adjustable.

However, under stock conditions you will never really notice when VVT-i is doing it's work or as you said, when it 'kicks in'. VVTL-i is a completely different story when it comes to noticing a difference.

[Evo7]

that is true,

VVT-i works different to VVTL-i and im not sure about yours, but mine does not 'kick' in, its more the foot is on the accelerator, the more the lifting valves are open, thats what vvti is in simple form :P

Evo

[Ascendant Rice]

dunno but somethign happens at 4k rpm engine gets louder rpms rise faster maybe its just me hitting peak torque and power

[SuperDave]

that is true,

VVT-i works different to VVTL-i and im not sure about yours, but mine does not 'kick' in, its more the foot is on the accelerator, the more the lifting valves are open, thats what vvti is in simple form :P

Evo

lifting valves?

The VVTi basically advances or retards the camshaft. It is constantly variable and has different stages of timing based on different rpm, and load. I don't know if the dual VVTi has any more intelligence than that. I'm told the original VVT, I haven't looked into it, was rather crude in that it just changed timing at x rpm much like how lift works.

The noise at 4k might be caused by bypass valves in the intake or exhaust opening?

[chicaboo]

A timing advance is usually associated with a bit of exhaust growl. But you should get no "kick" with VVTi, since it's variable.

I drove a ZZE122 sedan around Tazzie back in 2003, I could feel a slight power increase at 4000rpm, but no associated noises.

In my Sportivo, I also feel the engine perk up at 4000rpm the same way you do. But there is a distinct kick until 6200rpm. :D

Gav.

[Hiro]

Coming out of a resonance/torque-hole maybe, in first gear my 7A gets a noticeable kick at about 4000 (combined with a growl), and thats with no VVT or lift or TVIS or anything. Even N/A engines rarely have completely linear power/torque delivery.

[spillige]

minilift ftw <_<

[robie]

im just understanding how vvti works not too sure how dual vvti works but i imagagin it sthe same except that teh exhaust is also variable.

i notice vvti kick in around 4k rpms on my rolla which kinda sucks casue if i drive normally i never get that high in the rev range due to the auto tranny, although having said that my ecu has learnt to shift more around 5k rpm.

so when does your vvti kick in? how noticible is it?

vvti never really kicks in coz its never off its constantly working to give you best power delivery for your driving style

what your experiancing is more then likely the point were the cam makes optimal power like wat piro said

how al that works is pretty complex but it has to do with over lap (both exhaust and inlet open together) duration (how long inlet and exhaust valve stay open) and lift (how much the valve opens)

when you design a road car the cam is normally very conservative with power and lil torquer the a perfomance car with peak power figures around 3-4000rpm

wen comparing peak power figures to performance (n/a) cars like the stivo rolla honda type r etc which is around the 7-8000 rpm range

then comparing to turbo cars which have such a broad powerr and torque curve its almost linear making power and torque from as low as 2500rpm through to 5000 even 7000 rpm on performance turbo engines

[Modena]

Don't confuse VVTi with VTEC YO!

VVTI is always "on".

[Hiro]

Don't confuse VVTi with VTEC YO!

VVTI is always "on".

You can safely confuse VTEC and VVTL-i though, whilst completely different in operation they are the same in effect.

[Ray89]

mmm dual vvti with everything stock you will not hear, only maybe notice abit more power coming in after 4k rpm, after i put in my CAI, wasnt much of a noticable power gain but there was some tested the before and after with my friends scan gauge 101kw change to 107kw dunno if its acurrate but there was an increase, but you can hear engine the engine sound change after you hit 5k rpm all the way to 6.3k rpm.

[Blind Kid Seeks]

... you can hear engine the engine sound change after you hit 5k rpm all the way to 6.3k rpm.

heheheheh

but ... hehehehee

man i love the 2zz

[whitestivo]

can someone please post this thread in the humour section

every time i read the title I can't stop laughing

I can sometime feel my fourth injector come on line at 4000rpm

I once felt my ignition spark at 3000rpm

ROFL

whitestivo

[Lift yo']

i did a bit of researching about 4 years ago when i first got my stivo.

i was comparing the toyota's vvti vvtil to the honda's vtec and ivtec

heres a few links i have gathered..

http://autospeed.com/A_110859/cms/article.html

History of vvti

http://www.autotropolis.com/wiki/index.php...le_Valve_Timing

Last link explains Dual vvt and some videos too..

http://kereta.info/how-toyota-vvti-engine-...ng-intelligent/

i hope this helps...

Andrew,

[Lift yo']

can someone please post this thread in the humour section

every time i read the title I can't stop laughing

I can sometime feel my fourth injector come on line at 4000rpm

I once felt my ignition spark at 3000rpm

ROFL

whitestivo

ahahahah.... nuff said... lol

[Dav0]

Rofl... cmon guys.. mini lift.. dont try and compensate for not having a 123

[Ray89]

can someone please post this thread in the humour section

every time i read the title I can't stop laughing

I can sometime feel my fourth injector come on line at 4000rpm

I once felt my ignition spark at 3000rpm

ROFL

whitestivo

ROFL!!!!!!

[MR22ZZ]

oh god... not this crap again...

[europa]

dunno but somethign happens at 4k rpm engine gets louder rpms rise faster maybe its just me hitting peak torque and power

Is it your transmission kicking down a gear?????? It pains me to say it as I'm soon buying one but the 152's I've driven seem to do absolutely nothing when climbing up in revs, in a manual transmission equipped model - power curve and noise is as flat as five year old lemonade. Nothing happening here, move along (slowly)...

[Ascendant Rice]

dunno but somethign happens at 4k rpm engine gets louder rpms rise faster maybe its just me hitting peak torque and power

Is it your transmission kicking down a gear?????? It pains me to say it as I'm soon buying one but the 152's I've driven seem to do absolutely nothing when climbing up in revs, in a manual transmission equipped model - power curve and noise is as flat as five year old lemonade. Nothing happening here, move along (slowly)...

no its not a gear change down. maybe its somethign to do with auto i dunno next meet ill show some one if u dotn beleive me.

[chicaboo]

Don't worry about the nature of the power in your car William. You've got all the following things contributing towards what you may or may not feel:

1. Auto transmission going from stall to lock.

2. Cams climbing onto their powerband.

3. VVTi changes (blah blah blah).

4. Changing the fuel you use each day.

5. Humidity.

6. Temperature.

7. How much weight there is in the car.

8. Big shiny wheels... :P

9. The grade of your engine oil...

Don't worry about it, it's all normal.

Gav.

[spillige]

... you can hear engine the engine sound change after you hit 5k rpm all the way to 6.3k rpm.

heheheheh

but ... hehehehee

man i love the 2zz

^^

i know this is 2zz owned forum but can i say this, in all honasty the 2zz is nothing special ive never been a fan of vtec, vtil engines get stuck in the wrong gear, rpm range and youll get owned by much slower/less powerfull cars. thats the down side to these high reving engines.

therres no substitute for forced induction

flame sheild on :(

[TCSportivo]

... you can hear engine the engine sound change after you hit 5k rpm all the way to 6.3k rpm.

heheheheh

but ... hehehehee

man i love the 2zz

^^

i know this is 2zz owned forum but can i say this, in all honasty the 2zz is nothing special ive never been a fan of vtec, vtil engines get stuck in the wrong gear, rpm range and youll get owned by much slower/less powerfull cars. thats the down side to these high reving engines.

therres no substitute for forced induction

flame sheild on :(

OMG! GET OUT!!!! haha jk. I've done the opposite to what most pll do I suppose. Ive went from a turbo s15 to a Sportivo early this year and currently am loving the high revving engine and the sensation of lift. The loss of power and cornering ability was strongly felt, but the stivo still has plenty of both to make it a really fun car to drive. I 've always had a soft spot for the 'underdog' NA cars who often have a different philosophy to modding. I would have loved to have bought an integra type r but the whole reason I went to the stivo from a 15 was for practicality and 4 doors.

- Will

[Ray89]

... you can hear engine the engine sound change after you hit 5k rpm all the way to 6.3k rpm.

heheheheh

but ... hehehehee

man i love the 2zz

^^

i know this is 2zz owned forum but can i say this, in all honasty the 2zz is nothing special ive never been a fan of vtec, vtil engines get stuck in the wrong gear, rpm range and youll get owned by much slower/less powerfull cars. thats the down side to these high reving engines.

therres no substitute for forced induction

flame sheild on :(

OMG! GET OUT!!!! haha jk. I've done the opposite to what most pll do I suppose. Ive went from a turbo s15 to a Sportivo early this year and currently am loving the high revving engine and the sensation of lift. The loss of power and cornering ability was strongly felt, but the stivo still has plenty of both to make it a really fun car to drive. I 've always had a soft spot for the 'underdog' NA cars who often have a different philosophy to modding. I would have loved to have bought an integra type r but the whole reason I went to the stivo from a 15 was for practicality and 4 doors.

- Will

well thats sorta my reason why i dont have my Honda CTR EP3 due to practicality my dad said only was a 2 door. so he got me the ZRE. o well his money :( really wish i got the ep3 but.