Vanos unit

[Red95///M3]

re: "When Vtec kicks in, the motor goes from tame to wild..."

And that's the problem. Honda VTEC, esp in, say, the GSR, is really peaky, with little torque down low . To exploit these engines, you have to get them above the VTEC switchover (very high in some models, like the S2000). To compare apples to apples, the SOHC V6 VTEC in my son's 98 Accord Coupe is a less refined engine overall than my E36 straight six with Vanos. Don't get me wrong, I like Hondas. The E36 is just a different league.

[golgbimmer]

Can someone explain to me what the vanos unit is and what it does?!

[SickFingas]

almost the same as VTEC on hondas

[Evad]

VTEC- Vtec is a much better system, becaseu VANOS only controls the a camshafts relative position. VTEC, is-literally a whole 'nother set of lobes on the camshaft. At a given RPM (6k on a integra Type R) the VTEC switches from the low-rpm lobes, to the high-rpm lobes. the high rpm lobes feature more LIFT and more DURATION. L and D are the BIG factors in cam-adjustment, while relative timing (which VANOS alters) is a smaller one..

It is my understanding that the VTEC system does not have another set of lobes on the camshaft, instead it uses hydraulics to open the second set of valves for each cylinder once the engine reaches a certain RPM.

IE: from idle to 4500rpm only 1 of the intake/exhaust valves are open per cylinder and then from 4500 on the second intake/exahuast valve is opened. (RPMS are for example only)

There is no switching invloved. You basically go from a 2 valve motor at lower RPMS which increases torque to a 4 valve motor for the extra top end rush of Fuel/Air. Thats why you feel that sudden rush of power because now all 4 valves are open.

Thats how I have come to understand it anyway. Who knows, I could be wrong.

[Alex Mc]

Originally posted by SickFingas
almost the same as VTEC on hondas

not really, yes they are both valvetrain technologies, but that's where the similarities stop.

VTEC is a much better system, and the new i-VTEC is even better.. it's actually a combination of VTEC and VANOS.

Vanos- ok, vanos is pretty simple really.. it's a hydraulically controlled system that alters the relative position of the camshaft. It can advance or retard the cam several degrees to maximize velocity/volume ratios for the motor and the load, thus making the engine more efficient.

The early ones, like a '93 325i motor have only two positions (like VTEC) and are only on the intake side, the euro motors (e36 m3) introduced infinitely variable VANOS on intake and exhaust, and now the like can be found on E46 motors.

VTEC- Vtec is a much better system, becaseu VANOS only controls the a camshafts relative position. VTEC, is-literally a whole 'nother set of lobes on the camshaft. At a given RPM (6k on a integra Type R) the VTEC switches from the low-rpm lobes, to the high-rpm lobes. the high rpm lobes feature more LIFT and more DURATION. L and D are the BIG factors in cam-adjustment, while relative timing (which VANOS alters) is a smaller one..

When Vtec kicks in, the motor goes from tame to wild, it's really a great way to do it.. and the new Ivtec is just that WITH the advantages of VANOS too!

yes, honda is very capable- they make the best 4-cylinder motors in the world. hands down.

and that's the leason on VANOS versus VTEC- or at least the bulk of it, it's really much more complicated but you get the jist..

[3.0LV6]

At this point, BMW does not have any engine technologies in mass production cars that alter intake and/or exhaust vale lift and duration?

It seems that i-VTEC from Honda and VVTi-L from Toyota have an edge over the current VANOS system from BMW. They both alter the cam phase and timing the same as VANOS but have the added advantage of a second set of cam lobes for high rpm power.

Makes you wonder what type of HP BMW could pump out if they developed something similiar.

[Kyle M]

Ummm... your are only correct if you are talking about the old VANOS system, and not valvetronic, here is a link to a GREAT article that talks about all the systems and tells you how BMW rules the planet they are good) Hope this helps to inform!!!!!

http://www.sportcompactcarweb.com/ar...hno_0202.shtml

Quote from article:
Every variable valve timing system in the United States is utter crap. That's right, VTEC included. Sure, variable valve timing has redefined our expectations of the piston engine, but the current systems, all of them, are nothing but a box of pushrods next to BMW's new Valvetronic system

[3.0LV6]

Oh man, you just made my day... I'm having a friendly debate with my Honda buddies on a V6 Accord message board Germans vs Japanese and we are argueing over who has the more advanced engine technologies.

So far I have the following all in favor of the Germans

1) Individual throttle bodies per cylinder (M3)
2) Continuously variable intake manifold. (745i)
3) A 50k Sports car (availabe in the US) that pumps out 333hp NA from a 6cyl. (The NSX is the only car I can even think of thats close and its only 290hp from a 3.2L V6 at a cost of 70k)

Now you just allowed me to add:

4) Continuously variable timing and lift for intake and exhaust valves.

[Kyle M]

noproblem, someone had to stick up for our cars and BMW