which one is better?
which one is better?
11-08-2000, 02:25 AM
#2
Drifting
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vtec kicks in at a certain rpm level and varies the valve timing to create more power. Variable valve timing with intelligence (VVTi) varies the valve timing continuously, not just at a specific rpm range, so I guess technically VVTi is more advanced. If anyone has any other information or feels I am off base please correct me.
11-08-2000, 02:40 AM
#4
vanos is by bmw, i think its also playing with the vavles, or intake, not sure...
bmw also has a dual vanos, which is more advanced, used on the euro-spec e36 m3, which already had 320 HP , i think the euro-spec has 350+ on the new E46
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Bad ass TL...but...
Cant afford Mods.....
bmw also has a dual vanos, which is more advanced, used on the euro-spec e36 m3, which already had 320 HP , i think the euro-spec has 350+ on the new E46
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Bad ass TL...but...
Cant afford Mods.....
11-08-2000, 09:58 AM
#5
Burning Brakes
Honda's VTEC has a 5th lobe on the camshaft that locks with the 2 different intake lobes (one high lift, one low life to create swirl). When it locks it turns both intakes into high lift, longer duration. VTEC is tuned on each engine to kick in at the point where the engine's torque curve starts to falter, and then picks it right back up with better breathing.
VVTL-I is a gear based system that and move the cam shafts, generally causing the same idea, alter the cams to keep the engine producing more power than a static shaft.
One problem tho, I've read in the mags that when the VVT kicks in, there's a 1/2 second freefall lag of no power while it engages.. Noticeable they say in the Celica.
While Honda's is Simple, simple to the point of award winning, it is not variable beyond the one engagement (tho I hear 2 step vtec is coming). However, being a hydraulic engagement of simply a 5th rocker arm, there is MUCH less to break or adjust or worry about, VVT from what I've seen from a cross section at a car show, is a complicated NIGHTMARE. but hey.. i hate toyota's anyway.. I affectionately call them DAMry's.
and correct VANOS is BMW's VTEC, co-worker just put in his order for a brangie new 540, $53k down the hole..
the Q45 has also had variable timing for several years, tho I don't know of any other Nissan's that adopted the technology.
Honda has had it for so long that it's in the DelSol, Civic, the lowliest, the others can't say that yet.
Other's can't make a 250hp 2.0l I4 either.
(250 hp domestic, our emmissions drag it to 240 here)
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Had 1989 Black CRX Si (Cracker)
Have 1998 Black Currant Accord EX4 Coupe (Watson)
Have 2000 Laguna/Fern TL (Sherlock)
VVTL-I is a gear based system that and move the cam shafts, generally causing the same idea, alter the cams to keep the engine producing more power than a static shaft.
One problem tho, I've read in the mags that when the VVT kicks in, there's a 1/2 second freefall lag of no power while it engages.. Noticeable they say in the Celica.
While Honda's is Simple, simple to the point of award winning, it is not variable beyond the one engagement (tho I hear 2 step vtec is coming). However, being a hydraulic engagement of simply a 5th rocker arm, there is MUCH less to break or adjust or worry about, VVT from what I've seen from a cross section at a car show, is a complicated NIGHTMARE. but hey.. i hate toyota's anyway.. I affectionately call them DAMry's.
and correct VANOS is BMW's VTEC, co-worker just put in his order for a brangie new 540, $53k down the hole..
the Q45 has also had variable timing for several years, tho I don't know of any other Nissan's that adopted the technology.
Honda has had it for so long that it's in the DelSol, Civic, the lowliest, the others can't say that yet.
Other's can't make a 250hp 2.0l I4 either.
(250 hp domestic, our emmissions drag it to 240 here)
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Had 1989 Black CRX Si (Cracker)
Have 1998 Black Currant Accord EX4 Coupe (Watson)
Have 2000 Laguna/Fern TL (Sherlock)
11-08-2000, 10:37 AM
#6
Burning Brakes
I have been informed.....Hope this isn't too long.
Double VANOS System, or variable camshaft control. Techies may recall that the original VANOS System worked by on/off timing control of the intake camshaft. It was an ingenious method by which BMW engineers overcame the basic limitation of the camshaft: its design is dictated by the required overall engine performance. An early intake setting on the cam will produce higher performance at lower engine speeds, but the advanced position will create exhaust/intake overlap that tends to cause a rough idle. Retarding the intake cam timing will provide a nice idle, but the lack of flow at high engine speeds will detract from high-end performance. The original VANOS System uses an electro-hydrauli cally controlled two-position piston, a modified intake cam secondary gear drive with helical gear, and a helical gear drive on the intake cam to give an advanced position at mid-range rpm’s and a retarded position at idle. It was the best of both worlds, until now. Double VANOS allows true variable control of both intake and exhaust cams for increased torque in low and mid-range RPM bands with no loss in the high end, less unburned gases when idling, internal exhaust recirculation in the part-load range for lower NOx emissions, quicker warm-up cycles for the cat, and improved fuel economy.
co-worker also states:
VANOS which provides "steplessly" variable valve timing. Valves open and close at just the right instant for maximum performance, because the system is electronically controlled in response to engine speed, load and temperature. The result: optimal performance and economy at virtually all engine speeds. In another maximum torque at low engine rev. There's how the 540i can achieve 324 lb-ft @3600 rpm.
Hope this helps.
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Had 1989 Black CRX Si (Cracker)
Have 1998 Black Currant Accord EX4 Coupe (Watson)
Have 2000 Laguna/Fern TL (Sherlock)
Double VANOS System, or variable camshaft control. Techies may recall that the original VANOS System worked by on/off timing control of the intake camshaft. It was an ingenious method by which BMW engineers overcame the basic limitation of the camshaft: its design is dictated by the required overall engine performance. An early intake setting on the cam will produce higher performance at lower engine speeds, but the advanced position will create exhaust/intake overlap that tends to cause a rough idle. Retarding the intake cam timing will provide a nice idle, but the lack of flow at high engine speeds will detract from high-end performance. The original VANOS System uses an electro-hydrauli cally controlled two-position piston, a modified intake cam secondary gear drive with helical gear, and a helical gear drive on the intake cam to give an advanced position at mid-range rpm’s and a retarded position at idle. It was the best of both worlds, until now. Double VANOS allows true variable control of both intake and exhaust cams for increased torque in low and mid-range RPM bands with no loss in the high end, less unburned gases when idling, internal exhaust recirculation in the part-load range for lower NOx emissions, quicker warm-up cycles for the cat, and improved fuel economy.
co-worker also states:
VANOS which provides "steplessly" variable valve timing. Valves open and close at just the right instant for maximum performance, because the system is electronically controlled in response to engine speed, load and temperature. The result: optimal performance and economy at virtually all engine speeds. In another maximum torque at low engine rev. There's how the 540i can achieve 324 lb-ft @3600 rpm.
Hope this helps.
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Had 1989 Black CRX Si (Cracker)
Have 1998 Black Currant Accord EX4 Coupe (Watson)
Have 2000 Laguna/Fern TL (Sherlock)
11-08-2000, 07:08 PM
#7
Pro
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Originally posted by Sherlock:
I have been informed.....Hope this isn't too long.
Double VANOS System, or variable camshaft control. Techies may recall that the original VANOS System worked by on/off timing control of the intake camshaft. It was an ingenious method by which BMW engineers overcame the basic limitation of the camshaft: its design is dictated by the required overall engine performance. An early intake setting on the cam will produce higher performance at lower engine speeds, but the advanced position will create exhaust/intake overlap that tends to cause a rough idle. Retarding the intake cam timing will provide a nice idle, but the lack of flow at high engine speeds will detract from high-end performance. The original VANOS System uses an electro-hydrauli cally controlled two-position piston, a modified intake cam secondary gear drive with helical gear, and a helical gear drive on the intake cam to give an advanced position at mid-range rpm’s and a retarded position at idle. It was the best of both worlds, until now. Double VANOS allows true variable control of both intake and exhaust cams for increased torque in low and mid-range RPM bands with no loss in the high end, less unburned gases when idling, internal exhaust recirculation in the part-load range for lower NOx emissions, quicker warm-up cycles for the cat, and improved fuel economy.
co-worker also states:
VANOS which provides "steplessly" variable valve timing. Valves open and close at just the right instant for maximum performance, because the system is electronically controlled in response to engine speed, load and temperature. The result: optimal performance and economy at virtually all engine speeds. In another maximum torque at low engine rev. There's how the 540i can achieve 324 lb-ft @3600 rpm.
Hope this helps.
I have been informed.....Hope this isn't too long.
Double VANOS System, or variable camshaft control. Techies may recall that the original VANOS System worked by on/off timing control of the intake camshaft. It was an ingenious method by which BMW engineers overcame the basic limitation of the camshaft: its design is dictated by the required overall engine performance. An early intake setting on the cam will produce higher performance at lower engine speeds, but the advanced position will create exhaust/intake overlap that tends to cause a rough idle. Retarding the intake cam timing will provide a nice idle, but the lack of flow at high engine speeds will detract from high-end performance. The original VANOS System uses an electro-hydrauli cally controlled two-position piston, a modified intake cam secondary gear drive with helical gear, and a helical gear drive on the intake cam to give an advanced position at mid-range rpm’s and a retarded position at idle. It was the best of both worlds, until now. Double VANOS allows true variable control of both intake and exhaust cams for increased torque in low and mid-range RPM bands with no loss in the high end, less unburned gases when idling, internal exhaust recirculation in the part-load range for lower NOx emissions, quicker warm-up cycles for the cat, and improved fuel economy.
co-worker also states:
VANOS which provides "steplessly" variable valve timing. Valves open and close at just the right instant for maximum performance, because the system is electronically controlled in response to engine speed, load and temperature. The result: optimal performance and economy at virtually all engine speeds. In another maximum torque at low engine rev. There's how the 540i can achieve 324 lb-ft @3600 rpm.
Hope this helps.
http://www.fortunecity.com/silversto...gine/vvt_1.htm
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2000 Naples Gold 3.2TL/Navi - Factory Stock but with up-graded tires
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11-08-2000, 07:30 PM
#8
Guest
Posts: n/a
Fwiw, Alfa Romeo had variable timing on it's intake cams on four cylinders since the seventies this with fuel injection starting in 1969 on all production cars headed to the U.S. market .Pretty neat when you consider there was not a single computer in any of these cars untill 1982.
Holy shit!