[ericsmc83]

Just wanted to post a couple datalogs from last night. I consistently get a timing drop at ~4500rpm with every 3rd gear run I datalog. Sometimes (maybe every 4th datalog) I get another at ~6200rpm. Car otherwise feels very smooth, and I've never thrown a code/CEL. Is this something I should look into?

Current setup:
* Apr 08 build E92 335i
* MSD81 w/ 29.2
* 7k miles
* V4 2-23 Stg 1+
* Vishnu DCI
* AE Quad Catless
* 92 oct
* Everything else stock







And the log files for reference:
http://ericsmccormick.com/bmw/20100313_stg1+_3rd_1.csv
http://ericsmccormick.com/bmw/20100313_stg1+_3rd_2.csv

[ren]

Originally Posted by ericsmc83

Just wanted to post a couple datalogs from last night. I consistently get a timing drop at ~4500rpm with every 3rd gear run I datalog. Sometimes (maybe every 4th datalog) I get another at ~6200rpm. Car otherwise feels very smooth, and I've never thrown a code/CEL. Is this something I should look into?

I have the same thing in my datalog around 4300rpm and Shiv told me that it's a normal timing drop caused by a cam timing phase shift (his exact words).

[OpenFlash]

Yep! The 4500rpm timing retard is normal and very common if you go WOT through that RPM point. Don't try to work it out by raising ignition correction or else you will set to tune too conservatively and be down on power. As for the top end retard, if it's only happening every few times, leave it alone. It's really unnecessary to adjust the tune so you never get knock retard. Unless, of course, you are running 110oct and nitrous and making 600hp. But that doesn't apply to 99.9999% of us

Shiv

[supracg]

but v4 owners won't have to worry about any of these manual adjustments soon right

[OpenFlash]

Originally Posted by supracg

but v4 owners won't have to worry about any of these manual adjustments soon right

Nope. And they really don't have to worry about anything now either. Custom tuning is completely optional as it is.

Shiv

[ericsmc83]

Originally Posted by erensf

I have the same thing in my datalog around 4300rpm and Shiv told me that it's a normal timing drop caused by a cam timing phase shift (his exact words).

Cool, this is what I was hoping was the cause.

I'm going to try datalogging the Stg 2 map as soon as the weather is decent to see if I can squeeze a bit more power out of my current setup "safely".

Thanks for the help!