VVT mod Does this work?

[rally4life]

After years of thashing my holden Barina around the local hillclimb circuit in the AKL north aera i ve made the purchase and bought a 92 levin gt apex 20v, this is almost finished manz rollcage and race seats c56 gearbox with LSD, next was to see if there was some basic mods and have a read aronud the forums on toyotas and found Toyspeed most helpful- thanks to you all, I dont want to do to much to the motor as yet but some easy mods could be on this is one i have found and would like some feedback on what you think or know
Modifying VVT : is to install a manual switch to earth so you can control when the VVT is on or off. This would only be used once warmed up and on a special stage my goal would be to incress touqe

[barryogen]

I'm going to go with not such a great idea.

I mean a bit of VVT-i tuning may be in order, but I'd think that unless you're changing cams etc that there would be little advantage if any to making it switchable.

[Alex B]

Its not VVT-i they are diffrent.

[barryogen]

it says vvt-i in the subject, I ass-u-me'd it was correct.

dunno then, ignore my comments.

[sergei]

Not going to gain anything (apart maybe some weird looks for lumpy idle).
VVT is on anyway until it reaches 6800-7000rpm then it switches off, at that point you will be grabbing another gear.

[Mr Revhead]

nope, leave it as the ECU switchs it
it switchs on when warm pretty much straight away anyway
so no point at all

[rally4life]

Sorry guys i have changed the title - I have 2 Toyotas a late model corolla
with VVT-I my levin has VVT

[rally4life]

At what rpm does the VVT switch on /

[sergei]

Leave VVTi alone as well. it is continuous and has map on its own. VVTi is not just ON/OFF but it is PWM controlled which changes timing continuously.

[sergei]

At what rpm does the VVT switch on /

from idle, providing there is enough throttle open to trigger.

[flygt4]

from his original post it looks to be VVT as found on silvertop.

pretty sure some people have tried playing with VVT on dyno and found that the factory setup is ideal.

[xsspeed]

whats the diff between vvt and vvt-i ?

i cant remember exactly, s/top has vvt right? so what bout b/top?

[®usty]

so what toyota's just have VVT

[flygt4]

pretty sure silvertops run VVT only.

i think VVT-I is infinitely variable, the i standing for intelligent. its always changing depending on engine load, rpm, gear etc etc. ie there is no definable switching point/amount.
it came on 3SGE in caldina (intake only) , 3SGE in mr2 and altezza (intake and exhaust), its on the toyota echo in the 1500cc engine found there, after 2000 pretty much every small engine was using some kind of VVT-i.

VVT was the original version which i think has the set switching point.

i'm unsure which the blacktops use though.
it doesnt really make much more power , just improves torque down low.

[Bling]

whats the diff between vvt and vvt-i ?

i cant remember exactly, s/top has vvt right? so what bout b/top?

both VVT, don't believe what some sites say about this.

[cogent]

silvertop VVT seems to be done on throttle position and water temp rather than the vtak styles RPM trigger.

[Mr Revhead]

yep

varible timing is done according to the ECU map etc
valve lift (like 2zzge) is RPM switched.

VVT in the 4ages is not RPM switched

[matt dunn]

VVt is simple, the ECU turns it on or off and know's it is on or off.


VVT-i is infinatly variable and can be on off, partly on, 1/4 on, 3/4 on,
what ever the ecu wants,

BUT the ecu needs to know where the cams are, think of it as closed loop VVT,

so it needs a camshaft postion sensor on each camshaft, as well as one on the crankshaft so is way more complicated.

[Alex B]

it came on 3SGE in caldina (intake only) , 3SGE in mr2 and altezza (intake and exhaust), its on the toyota echo in the 1500cc engine found there, after 2000 pretty much every small engine was using some kind of VVT-i.

Pretty sure the redtop 3s as in MR2 are only on inlet cam.

[®usty]

so VVT is not in Celica (but only as VVT-i in SSII & SSIII 97 -99)

right?