Audi proudly bears the 5V logo on the engine just like how Honda/Acura put the VTEC emblem on and employs it in almost every single one of their cars. What advantadges/disadvantadges are there to 5 valves vs. 4? I heard it gives more torque and a flatter dyno curve (torque wise). If 5 valves is so great then why don't all auto manfactures use it? Any help is appreciated

 

because ferrari's uses 5.

 

It has more power across the board in a wide range. It also revs freely much like our vtechs...... No real advantage, I guess it's vw's way to compete with honda's vtech. Much like toyota's vvt-i and bmw's double vanos.

 

I don't think having one more valve per cylinder has anything to do with valve lift control and timming (vtec,vvt-i, etc)

 

I think I got it. Our four valve system has 2 for intake and 2 for exhaust. 5 valve system has 3 intake valves and 2 exhaust valves.

The Audi five-valve engine owes its effectiveness to the intensive ventilation obtained through five valves per cylinder and the ultra-point fuel injection system's electronic fuel distribution. This new technology, as dependable as it is advanced, guarantees a high level of efficiency, even at low rpm's.

See pic:

 

kind of what I said power across the board. I didn't mean to refer the 5v to vtech or anything. It's just audi's way of making efficient hp and torque through there own technology, as honda uses the vtech to do the same.

 

k

 

I'm sorry I don't make sense right now. It's late and I had a loooonnng commute to work, so right now I don't make sense. Whatever the case is, Audi is a horrible car company as far as reliability goes. I've had friends who owned S4's and tt's and they all had some problems with the engine and the whole car itself. *Sigh* I need some Starbucks.................

 

That excuse won't work today with me...hehe.....check this:

http://www.acura-tl.com/forum/showth...threadid=19144

Plus is estern time here in florida

 

Three intake valves put a lot of spin on the incoming air, which keeps the flow all nice and laminar while increasing intake speed. This has the bonus of normalizing the distribution of fuel and oxygen. Exhaust is two valves because post-detonation its rather turbulent anyway, and noone cares about how it exits the cylinder.

 

for v6 with a similar displacement as the 3.2 with their version of vvti and they only get 190 hp. the new version gets 200+ but not even close to 260...

 

and the nsx uses the same 3.2l volume to obtain 290hp. can't wait to see what they can optimize the 3.5l to do!

 

There are pros/cons just as in anything else. BTW, Ferrari and others have used 5V heads.

Benefits include high flow, low moving mass, and ability to optimize flow for a given cylinder dimension, piston crown shape, etc.

Disadvatages: more valvetrain capacity, more sensitivity to deposits and heat warpage, likely not as durable.

Honda's SOHC system would be very tricky to implement with 5V, and with the power its gets frok a simple, reliable, and less costly SOHC system, why bothe

 

got my new Road and Track and I can't wait to see the vtechized 4.0 V8. Acura made that much power and acceleration with a 3.2
V6, can you just imagine?!?!? In a few years that may be my new car.....

 

i would just like to point out that the first gen 2.5TL's are also inline 5's aren't we so special? hehe

 

AN inline 5 is a 5cylinder engine which still had 4 valves per cylinder for a grand total of 20 valves. Thats not what they are talking about. They are talking about the Audi 4 and 6 cylinder engines which have 5 valves per cylinder for a grand total of 20 and 30 valves respectively.

 

oh haha, silly me, i'm dumb what can i say. but i still have a damn nice car!!!!

 

I read a while back that the next generation NSX and the RL (Legend) would be having a 5Valve per cylinder DOHC engine design.... but contradicting rumors later on, did not seem to indicate so..