Disabling VVT, VVTi, VVTL-i

[-e f i n i-]

I am really quite confused here. I see many people disabling the toyota VVT system. After looking at Toda parts list too, I wonder, how come the adjustable cam pulleys for 4AG requires VVT to be disabled, but the adjustable cam pulleys for VTEC dont need the system to be killed.

Is it because adjustable VVT cams just cannot be done? is it just incapable of timing your cams?
Now now, how about 2ZZGE VVTL-i? For best results, VVTL-i has to be killed too?

I remember once william aka wkautech said he can kill the VVT system and make more power from it.
I also remember reading from Bill Sherwood's site, VTEC and VVT holds very little opportunities for high power NA gains.

PLease enlighten me. Thanks.

 

[EFN]

I will do my best to put it as simple as possible.

VVT was first designed to cater for efficient power to drivability experience. VVT was not designed for outright power. After owning 2 separate engines running 2 different VVT systems, I can tell that VVT does help a lot in boosting up performance whenever you press the pedal (yes VVT is not RPM triggered). VVT itself is a "self-adjusting" Intake Side Cam Pulley.

So why does disabling VVT makes more power? you see, when u start tuning for outright performance, you will forget about letting the car "self-adjust" the optimal settings for you (VVT & VVTi does this). Extreme tuning is all about setting the car to run exactly as how you want it to behave and thus became very predictable. Disabling VVT is all about removing the VVT pulley and replacing it with manually Adjusted Cam Pulley. Manual Adjustment will allow for tuning to the desired powerband depending on application, usually one would set the cams overlap so that it will flow the best at Higher RPM

VVTL-i is a different story, L means it has lift like VTEC and MIVEC, Since it is more akin to VTEC, removing it will surely degrade performance and I just can't imagine how one would go about removing the lifter - unless you owns two or three banks and can literally buy any "non-lift" sets TODA can offer.

 

[Danny101]

bro,
different all together mah, vvti=variable timing(self advance/retard of ignition timing) vtec=variable lift(self adjustment to high/low camshaft profile), vtec also can be disable mah, just buy toda vtec killer camshaft........hehe :p

 

[-e f i n i-]

Hmm... since VVTL-i and VVT, like you mentioned are 2 different things, and also...there are adjustable cam pulleys for VTEC, there should be also adjustables for 2ZZGE right, if not in the future?
So i was wondering, if a 2ZZGE is equipped with adjustable cam pulleys and also VVTL-i, it will make quite high power on high revs right?
Or would people suggest to have its VVTLi system killed like VVT in order to make more power?
Since 2ZZGE is a relatively new engine, it would sure take a longer time for parts to get developed. I've been searching around and still cant find any cams nor cam pulleys for 2ZZGE.
and since EFN said VVTL-i is like VTEC, I hazard a guess that the camshafts for VVTL-i will be like those for VTEC engines too? i mean, 260-302-260?

And Im also wondering if a 2ZZGE can use 4 throttle?
Anyway, whats the rational behind killing the VTEC system? I was told those VTEC killer cams are for turbo application, but the duration looks pretty much too high for Forced Induction. Havent checked on the lift yet though.
Still looking for an answer to the significance of killing VVTL-i, if necessary. If VTEC can be killed, VVTL-i should be able to be buried too right?

Dont kill me please, but im still dreaming of a 300HP NA 2ZZGE.

 

[EFN]

If you have to know, then the only time you might want to kill lifter cams setup is when 200WHP on NA motor is not enough. For example, TODA VTEC Killer cams are designed in such a way that it will provide such a very high lift and duration that it is not feasible at all to run it together with VTEC lifters. Oh yes they runs very-very rough idle around 2000RPM and only make power after 6000RPM.

 

[-e f i n i-]

The idle doesnt bother me really, racing cams are like that.
Hmm.. so you mean to say lifter cam setup like VVTL-i only has to be killed when you surpass the 200WHP NA mark and still not satisfied. why?

 

[EFN]

The idle doesnt bother me really, racing cams are like that.
Hmm.. so you mean to say lifter cam setup like VVTL-i only has to be killed when you surpass the 200WHP NA mark and still not satisfied. why?

Simply because NONE of the motors that run over 250WHP are still running on lift mechanism. But the main point is this sort of application is purely for all out motor only - tuners prefer to have something linear (predictable) in power delivery and not RPM or TPS triggered power shift point. For example, TRD Formula Atlantic 16V engines are known absolutely to produce peak power from 5000 to 12000RPM - same goes for TODA and Mugen non VTEC motors. I doubt Honda F1 have VTEC, or Toyota F1 uses VVTL-i

 

[Acoustic]

mua hah h h ahah hhha

if only all of us are engineers and specialist in "time domain" then you'll automatically understand why these technologies are invented and constantly worked on and further improve.

hahahahahahahahahah

if these system are no good, why are they in F1 ??? obviously F1 have event more sophisticated systems lah..... imagine those put on mass-produced road cars :) dam efficient :)

efini - engine breaths differently at different rpm ..... these systems are invented based on understanding of the breathing difficulties of the engine under various conditions and hence optimised step by step

VVT is the 1st step
VVT in 20v is already like 1/2 VVT-i (triggers by TPS vs. RPM)
VVT-i finally appears
VVTL-i another step forward.

Unlike V-TEC - they are great, those engineers were greedy enough and crazy enough and dedicated enough and motivated enough to take all the troubles on this world to make it happens :)

I salute the V-TEC engineers for their bravery, ut-most dedication, sacrifices I'm sure we don't know about, no-fault operations....
V-TEC devices are so god dam small - they look like they'll break when you shout at it, yes it's so fragile, but we've never heard of a V-TEC failure have we???
It took toyota so many years to get a similar system working ..... that still toyota aim for drivability, unless V-TEC outright power.

If one complains the engine have no power, it's not the VVT fault, nor the VVT-i, nor the VVTL-i. It's the whole package. Cam durations, overlap duration, profiles, lift, valve opening, intake angle, intake diameter, intake velocity, combustion swirl efficientcy, combustion heat containment efficientcy, so many things....

It really pays to understand each category and pay respect for law of physics of this universe.

It would be difficult to ignore science and simply quote what do I buy so that I can get 1000000 bhp.

It's also like human breathing against the wind on the motorbike..... can't breath right, but anything wrong with the health? NO, I'm sure no problem, the situation just changed, like engine breathing, different rpm, different scenario, need different part of the system to work.

 

[-e f i n i-]

I heard Power FC controls the variable timing function.. hmm, even if we didn't disable the VVTL-i and make it rev even higher, will it make as much power as a 2ZZ with disable VVTL-i, adjustable pulleys and higher redline RPM? Say for both of the engines, we have them pull all the way to 11,000 rpm for peak power gain.

Anyway, I was wondering, Formula Atlantic uses 16V AE86, Toda and Mugen use non-vtec engines. If we disable the VVTL-i system and the engine made for competition only, will it be worth the sacrifice? Will there be more pros than cons with the VVTL-i absent?
Since engines breathe different at different RPMs, if its meant for racing, its always good to use high cams, right? Street and track are both two different ball games.
Hmm and I also found out 2ZZ cams have 2 lobes and not 3 lobes, is that true? but are there still secondary rocker arms present in the engine, like VTEC?
Since 2ZZGE is an aluminium block engine, can it rev high?

Now my hopes have risen to 350hp NA setup, but i also dont dare dream high high cuz still searching for its possibilities. hey everyone has the rights to dream right??

Thanks.

 

[Acoustic]

efini - you are a good guy, you do research, reading, study and all, but even the internet is useless when it comes to out-right "answer(s)(s)(s)(s)" that you need, and the only place I know which can answer all your question is ....

textbooks of engine fundamentals

Believe me, I've read a few, after reading I shut-up.

Forget about VVT, V-TEC, adjustable, high rev, high cam, throw every you've learned so far all away into the pass and pick up a text book and re-learn like Luke Skywalker meeting Master yoda for the 1st time.

After you do that .... you are a changed person....... you will no longer dream, instead you will know how to achieve your dream.

 

[rollakid]

:D indeed he's a good guy :D study hard hard and do lots of research. i had most fun when chatting with him, not like other online pals who just talk crap online. ;)

i think i'll need to get that textbook to lol, but not now lar, later brain blow up like engine, when working baru get spare time to read extra stuff hehehe. hmm... yoda... need go inside jungle find...

 

[AE80TypeD]

cheh... still 3.0 ppl lah suck what?? suck lollipop lah!

i studied 2 years extra until habis loan oso still stuck at 2.43CGPA... who sucks now?

sob sob :( :p kekeke

 

[-e f i n i-]

Sayang man... i was at KL this year but i did not go to Kinokuniya or MPH to find those engineering books. ARGHH!!!!
T__T dont be so sarcastic la guys T________T
I dont think i did any research ler.. all i did was pester you guys in forums only. ask ask ask ask ask everyday stupid questions. wuwuwuwuwu. sorry ya, guys...
rolla ah... i think all i did was make u fed up in msn only.... make you repeat your explanations over and over again T_T

 

[synchron]

I think you should try Borders, the new bookshop on Timesquare. They got tones of automotive books there. They books on ecu, blueprint, chasis, suspension, force inductions and more.

 

[-e f i n i-]

Will go there and see see when i go to KL again. Haha.. im not sure if the booksotres here do sell them. But my sis last time had to go KL to get her books. So maybe, i cant get it here... nevermind.. i will still go find haha