[edo]

Hi,

did some data logging today - 3-4 gear WOTs.

Comments are welcome.

7-14, stage 2, UT-80%

1st run - 100% ignition correction:


2nd run -100% ignition correction:


3rd run - 75% ignition correction:


4th run - 75% ignition correction:


Did 4 runs with 50% ignition correction. Last 2 runs:
7th run - 50% ignition correction:


8th run - 50% ignition correction:


It did some WOTs after I had changed ign. correction % and only then started data logging.

[edo]

BTW, any ideas why boost fluctuates so much?
It wasn't like this before...

[OpenFlash]

Judging by the logs, I'd leave it at 100%. Seems like the fuel quality in Lithuania might not be as good as it is here. And the boost looks fine. Since the last firmware update, we doubled the sampling rate which will make the graphs look more noisy. Perfectly fine and normal.

Shiv

[Kbueno]

Sampling rate aside, the boost should be confirmed with an actual gauge. I had logs like that (Rev I days) and could see the boost oscillate on the gauge as well.

[edo]

Originally Posted by shiv@vishnu

Judging by the logs, I'd leave it at 100%. Seems like the fuel quality in Lithuania might not be as good as it is here. And the boost looks fine. Since the last firmware update, we doubled the sampling rate which will make the graphs look more noisy. Perfectly fine and normal.

Shiv

Thanks for the reply, Shiv.
How do you juddge?

Strange, as the fuel quality is quite high here and I'm only using 98oct fuel (93 in USA).

I never had such fluctuations before. And I could feel that the acceleration wasn't smooth this time. And such amount of fluctuations is only when go WOT in 3rd gear from ~2k rpm. If I start in 2nd gear, everythin's much better.

Differences of boost is up to 2.5psi. Here's a crop of the first run:

[Mike@N54Tuning.com]

Clearly some issues there but as a general comment it is really interesting to see how fast timing wobbles when boost wobbles... Just goes to show how fast the DME is at making corrections.

Mike

[edo]

Originally Posted by Mike@N54Tuning.com

Clearly some issues there

I'm starting to hate my car...
Issues, issues, issues...

[kentgbr]

Originally Posted by edo

BTW, any ideas why boost fluctuates so much?
It wasn't like this before...

Seems to stabilize after ramp-up. Try reducing the throttle response user adjustable parameter.

[edo]

Originally Posted by kentgbr

Seems to stabilize after ramp-up. Try reducing the throttle response user adjustable parameter.

OK, I will. However, I didn't have such problems before.

Maybe hot weather could be the reason?

[chiefsotos]

With some firmwares before i had the same problem as you with the boost oscillation. It happens in all gears from 2000rpm till 4000rpm, but you specially notice it with high gears(3d and above). I have a boost gauge and it was really annoying thing. I have not problems with the maps of february 2009 and i have not tried the new maps to tell you if boost oscillation is there.
But i think some adjustment from Shiv to these new maps should be done in order to eliminate again all this oscillation!

Originally Posted by edo

OK, I will. However, I didn't have such problems before.

Maybe hot weather could be the reason?

[edo]

I'll try switching to older maps if I have time this weekend.
I uploaded the 7-14 map just before I went to log the runs I posted. I didn't have such boost problems before. So yes, I presume maps could be the reason. On the other hand, the majority here don't have such problems with new maps.
Arrhhh...

[jpsimon]

Yeah the ammount of oscillation is strange, I haven't seen that with the new maps

[NRG]

Somehow those boost fluctuations reminds me of time when I had V3 Rev1 installed for some time last year.

[yamsta]

This boost oscillation seems to be a common issue I believe with older cars running pre-29.2 software, someone correct me on this? I've seen the same oscillation (verified via a boost gauge) on a JB3 1.3 car.

[NRG]

Originally Posted by yamsta

This boost oscillation seems to be a common issue I believe with older cars running pre-29.2 software, someone correct me on this? I've seen the same oscillation (verified via a boost gauge) on a JB3 1.3 car.

I guess that depends on a car. My friend is pre 29.2 been running V3 Rev1 installed by me, for more then a year without a single problem. I however on a pre 29.2 had similar issues and non with JB's.

[yamsta]

yeah i guess it depends on car to car. there were a few threads about this a while back with many people reporting the same exact thing:

http://www.e90post.com/forums/showthread.php?t=232873
http://www.e90post.com/forums/showthread.php?t=261534
http://www.e90post.com/forums/showthread.php?t=244107

[OpenFlash]

Correct. Back in May, we isolated the cause of the low RPM boost oscillation and resolved it (with the 5-29 maps and corresponding firmware IIRC). All maps/firmware since then have the fix implemented. If boost is still oscillating, it's for a reason other than the actual mapping.

Shiv

[edo]

Originally Posted by shiv@vishnu

If boost is still oscillating, it's for a reason other than the actual mapping.

Shiv

Iny ideas what reasons? Apart bad fuel.

[jpsimon]

boost leak of some sort could cause that

[edo]

Originally Posted by jpsimon

boost leak of some sort could cause that

In such case the oscillation shouldn't dissapear...