Wat is VVTL???

[pnoiSR20]

I have been researching around for an SR20 motor. THey all mention about the new VVTL. Wat exactly is that???

[logik23]

I think it's Variable Valve Timing Lift, but anyways, it's a feature they had on the S14 and S15 SRs, it adds a little power in the top end by changiong the valve timing, I hope you know what that means.

[pnoiSR20]

I hear it is Nissan's answer to Honda's VTEC.

[logik23]

Yeah, but pretty much all companie shave it now, it's either like VTEC, VVT, VTC, VVTL, etc.

[publicenemy137]

it's like VTec pretty much, the camshafts change in accordance to RPMs to take in the right amount of air intake. What this means is the maximum amount of power for each RPM.

and it's VVTC, for variable valve timing chain, not VVTL

[wingsofwar]

Vtec doesnt change the timing it changes the lift by using different cam lobes at certain RPM. VVT changes duration of the valve openings without changing the lobe profiles. Ultimatly VVT and Vtec almost accomplishes the same thing, but they do totally different things.

[ghetto7o2azn]

vvtl is in the celica

[nissanfanatic]

It sound like one more thing to go wrong if you ask me.

[pnoiSR20]

Ok thanks guys.

[freelunch]

Does VTEC allow for different 'stages'? Like at high RPMs it runs the motors like a race motor, and scales it back at lower RPMs. Or is that i-VTEC?

[nissanfanatic]

It uses different lobes on the camshaft proportional to engine rpm to maximize fuel efficiency.

[fugiot]

VTEC is either "on" or "off". "High lift" or "low lift".

Nissan's VVL is a 3-stage system with the intake cam and the exhaust cam switching as different times.

Stage 1: intake cam= low lift, exhaust cam= low lift
Stage 2: intake cam= high lift, exhaust cam= low lift
Stage 3: intake cam= high lift, exhaust cam= high lift

[SHO411]

Sounds fancy but most ppl putting serious power tend to diconect all the above. Have no idea why, but vtec, and vvtl are never used when trying to produce big power well except for the RB and 2JZ, and any other big engines but on the smaller ones they take them off. Any one knows why????????

[NSX-R-SSJ20K]

when you change the cams you don't have Variable Valve Timing anymore simple as that

OK thats it

time to explain the different types of Variable Valve timing



This is the Variable Valve timing that changes the lobes.
Which changes the cam profile

The other type is VTC which is a helical gear at the end of the cam shaft which can advance or retard the timing of the cams.
Both systems are operated by oil pressure. The oil pressure turns the gear to increase valve overlap.
The one on the cam lobe increases the duration the valves are open.

good ey?