VVT-I setup

[rudiel]

A friend of mine told me that he shortened a spring on the VVT-I on his car to activate it on lower rpms, is this possible? If so, can it damage the car in a short term? Thanks.

[thebarber]

vvt is always active....it doesnt "kick-in" at any rpm in particular

[Yaris Hilton]

It's also not controlled by spring tension, as a mechanical governor is. The mechanism for rotating the intake cam is controlled directly by the ECU, which opens and closes a hydraulic valve to actuate it for advancing or retarding the cam and gets feedback on the actual cam timing from the camshaft position sensor and crankshaft position sensor. This is why they call it VVT-i. "Variable Valve Timing with intelligence."

[rudiel]

He gave me a ride a couple minutes ago to test his car. I notice an increase in acceleration at around 3,500 rpm. Now i am confused, you guys telling me it pretty much doesnt work and me feeling some gain on the car lol. Keep the comments going, they are appreciated.

[Dadombomb15]

maybe on a VVTL-i, but VVT-i engines don't have this "spring" you're talking about. On the VVTL-i, the spring you're talking about connects the slipper follower to the rocker arm. When the rpm's are above the set lift point, oil pressure slides a pin under each rocker arm switching it to the higher lobe of the camshaft giving it more lift for lengthier periods of time

VVTL-I engines have that extra kick but most of the time it isn't seen until far after 3500 rpm. my dad had an '07 Lotus Exige S for a while with the VVTL-i engine and damn did it move. then again it has a supercharger and an intercooler.

[rudiel]

Its a VVT-I. Tis is weird! lol

[Dadombomb15]

is the car bone stock?

[cali yaris]

look at a dyno of a stock Yaris. You'll see why you feel something at 3500 rpm. It's not necessarily the VVT-i

[ddongbap]

VVT-I JUST KICKED IN YO.

[ddongbap]

maybe on a VVTL-i, but VVT-i engines don't have this "spring" you're talking about. On the VVTL-i, the spring you're talking about connects the slipper follower to the rocker arm. When the rpm's are above the set lift point, oil pressure slides a pin under each rocker arm switching it to the higher lobe of the camshaft giving it more lift for lengthier periods of time

VVTL-I engines have that extra kick but most of the time it isn't seen until far after 3500 rpm. my dad had an '07 Lotus Exige S for a while with the VVTL-i engine and damn did it move. then again it has a supercharger and an intercooler.
Don't forget the car weighs 1 ounce.

[Dadombomb15]

Don't forget the car weighs 1 ounce.

this is true haha
fun as all hell to drive, greatly miss it :cry:

[rudiel]

CAI, exhaust, fuel regulator i believe

[rudiel]

ddong u an idiot lol

[YarisPR]

ddong u an idiot lol

El VVT-I en los 1nz NO activa. Si se siente mas fuerte a ciertas revoluciones pero NO es un V-Tec o VVTL-i. So NO activa. Veta a dar una vuelta en tu carro ventanas arriba y aire apagado y pisalo en una recta, vas a sentir como por las 5,550rpm "activa" pero NO activa na' es q se siente mas.

[hondakiller99]

um , isnt vvt-i activated 24/7 and ran off the throttle pos. sensor and retards when ur not beating the piss out of it and advances when u have the pedal to the asphalt?

[victorcr]

yaris es toda caminan rico

[victorcr]

Si Se Puede poner una Trabajar Mejor El VVT -i aqui en Costa Rica lo Hacen vale 1000 dolares Trabajo de El