Quote:
Originally Posted by ike84
Woody is right that in general the torque curves for the 2.7 and 3.2 don't start to peak until past 4k. I had never noticed the "kick" at 4200 before I did my intake and exhaust mods though. That's definitely interesting that your stock s does the same thing.
At first I wondered if it could be variocam switching over at different points depending on throttle and load but from everything I have been able to find that it always a fixed transition at 5500rpm. I posted recently about this topic but I haven't gotten any responses yet.
I have read similar comments about the timing but I'm not sure about it. I think that the base tune has ignition advanced to as early as stuttgart deemed "safe" and the only adjustments the dme will make is to pull timing if knock is detected. I've not seen any documentation that the dme will advance timing further if the fuel is higher quality. I've also not ever read that the dme will advance timing beyond the base map under specific circumstances such as wot or rpm threshold.
With that being said, you could be right that at a high enough rpm and load the timing becomes such that 91 will knock and then the timing gets retarded. I run 93 but it's the same tank that's been sitting since before I started all this work last fall, so I'll be curious to see what happens with the next fill up.
The other thing I wondered was the fuel maps in regards to open vs closed loop. Woody and I are running the 996 tune on 2.7 and 3.2 motors, respectively, and we should be encountering rich conditions when the dme flips to open loop mode. I would think that I should be so rich in open loop mode that it would probably hurt performance, where woodys probably wouldn't be effected much. I don't know of any way to actively monitor what mode the dme is running in though, unfortunately.
Sent from my POCOPHONE F1 using Tapatalk
|
I agree that the DME is most likely set up with the most advance that is safe under the right conditions.
I wonder if timing advance in regards to Octane or rather knock is learned in a similar way as fueling maps are????
I have read that today"s knock sensors pick up pre knock that you or I would never detect.
On my OBII scanner it shows rough running feedback for each individual cyl. also ignition timing for each individual cyl. So the DME is pretty adaptable.
Since fueling maps can be learned my guess is that fueling even in open loop conditions is learned. With the narrow band O2 sensors used on these cars they are constantly going back and forth from closed to open loop. WOT, and deceleration are two examples of when they will go from closed to open loop. So it makes sense to me that fueling would be learned even in open loop conditions.
So you may or may not be running rich in open loop.
A way you can monitor this is to hook up an OBDII scanner that shows open-vs- closed loop and watch it change back and forth as you drive.
I have done it several times with my scanner.