12v VR6 air/fuel mixture?

[KI11Z]

Jaaaaaaaay

ok, so vw assumes that they've taken care of the issue with the varied runner lengths and feel the one o2 sensor is good!

i'll pass it on

[Jmac]

What makes you think the computer is adjusting the mixtures on a per cylinder basis?

To do that would require the equivalent of 4 injection systems.

Some very modern cars are getting close to this with newer injection technologies but your VR6 is most likely just applying the same timing to all the injectors.

I'm not specifically familiar with the VR6 system but a lot of systems around that era just fired all the injectors at the same time with the same signal.

Bosch publish some really good training manuls on EFI, see if you can grab one off e-bay, they help a lot in understanding this stuff.

Pete

I agree , 1 pyro would be enough, and an o2 sensor. This set up is on the BAM engine TT, fore and aft 02 sensors and a Pyro for the 4 cyls. Now i do have the Bosch manual Pete is talking about and the Self study program for the VR, and pretty much matches Jays link word for word.
Interesting how far are you going with the engine mate and what stand alone are you looking at?????
Cheers
Jmac

[Bug_racer]

The intake runner lengths may be different , but when you look in the cylinder head the port sizes are also different . VW worked out the best port size for specific flow , doing a "port and polish" could upset this and then you could start going backwards in regards to power .

The VR6 was originally intended as a diesel engine before it was changed in design slightly becoming a petrol engine .

Also the ignition is ignited individualy per cylinder based off the knock sensors . Upon cold start up it has msd .

I would run 1 pyro or wideband lambda per bank for tuning

[beeza]

Well Alex, that is a very interesting scenario you have there.
The way i see it is that your cylinder head machinist should do his best at getting every intake and exhaust port the same. I'm not sure if its traditionally done on not but maybe pay him a little extra for cc'ing every port to make sure they are the same volume.
I guess doing things like delaying injector pulses should only be done if you are chasing "ultimate" power.
Oh, about the individual lambda sensors; I would have to assume that the only engines that need them would be the ones like M3s have. You see they run individual throttle bodies but they don't run off a main shaft so they are actually "individual" per cylinder. I can only see it fitting this type of application.
These are not facts or anything, they are just some of my thoughts.

[KI11Z]

. . . Interesting how far are you going with the engine mate and what stand alone are you looking at?????
Cheers
Jmac

umm, we havn't really discussed the computer side of things yet though Motec was thrown around during a conversation the other week.

The intake runner lengths may be different , but when you look in the cylinder head the port sizes are also different . VW worked out the best port size for specific flow , doing a "port and polish" could upset this and then you could start going backwards in regards to power . . . .

He's port matching everything so it should all be alright yeh . . .