VCT abilities - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

CSV_LS1 · 01-05-2004, 21:11

Is VCT similar or the same as Honda's version which gives a more agressive cam profile at a certain rev range? Would this allow for a fairly aggresive cam that would not usually be considered for street use to used and able to have decent low range power?

Casper · 01-05-2004, 22:47

the VCT (from my limited understanding) simply changes the timing of the cam at the 3700rpm range (in the AU at least).

Stolen from another thread:
VCT - Variable Cam Timing. IIRC the Falcon Six's VCT setup retards the cam timing by 10 degrees after the engine revs exceed 4000rpm(is actually 3700rpm). From my understanding of it, what happens is that when the engine revs exceed 4000rpm, the engine retards the camshaft timing 10 degrees in relation to the crankshaft position, which allows a better higher RPM cylinder fill. Unfortunately, it also retards the exhaust timing, being the Falcon's head is still an SOHC design. This feature should be better when the Falcon comes out with a DOHC head.

I'm not sure about the actual retardation, I thought it was 13 degrees however the concept is correct.

So can you use a more agressive cam? Thats a good quetion which I would love to find out myself.

redGhia · 01-05-2004, 23:55

The cam changes all the time aparently in the ba. if you have an auto and roll the car forward slowly in drive apparently you can notice the timing change even at just above idle

ianmcginley · 01-05-2004, 23:59

Quote:

Originally Posted by redGhia

The cam changes all the time aparently in the ba. if you have an auto and roll the car forward slowly in drive apparently you can notice the timing change even at just above idle

I can notice it in my BA XR6 manual :)

ianmcginley · 01-06-2004, 00:04

Quote:

Originally Posted by CSV_LS1

Is VCT similar or the same as Honda's version which gives a more agressive cam profile at a certain rev range? Would this allow for a fairly aggresive cam that would not usually be considered for street use to used and able to have decent low range power?

I'm not sure about Honda's VTEC, however it is similar to Toyota's VVT-i used in the 1.3, 1.5, 1.8 Echo/Corolla's. That is the cams vary with throttle position/load/requirements. However it does not effect the cam lift which is what Toyota have in the VVTL-i (variable valve timing and lift) which is the 1.8L 4 cylinder in the Corolla Sportivo and the Celica (142kW out of 1.8L ain't bad)

VTEC my guess is something to similar to VVTL-i which is the best of both worlds, allowing timing of the cams/valves to adjust to performance/economy requirements and lift to ensure maximum engine breathing (all the benefits of a lumpy cam without the idle problems).

Rollin · 01-06-2004, 04:53

on the AU XR6VCT the cam is retarded a little at idle (the actual number escapes me, though i was reading about it just the other nite) then is advanced slightly from just off idle to about 3700, when it is retarded again.

im pretty sure its not load dependant, only revs.