Full Access Member
- May 18, 2017
- Reaction score
- Treasure Coast, Florida
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
The above is a run at the track recorded with a Tech-2 and viewed on TIS2000 software. I also looked at several recorded passes made with the AutoCal on EFILive and no drop while the RPMs were climbing, even with KR.
Thanks for posting that.
Watching the vid, I am seeing some occasional dips by just a few g/sec in your MAF readings as it climbs, which aside from that I seem to be picking up some knock when it's happening on mine, seems similar in behavior.
Yeah, it isn't very much when it dips on yours, or mine really for that matter. Just maybe 5 or so g/sec for a split second then recovers. Maybe I'm over analyzing things. Who knows. I took another degree of timing out from 4000 up and did another log on the way to work this morning. It actually seemed to be a bit better when I did a WOT pull. There was still some knock, but measurably less than my last log so maybe I'm getting really close on the amount of timing it's going to need pulled in the upper rpm's to be happy. I'm still just a tad rich at WOT too. I'm still seeing that same pattern of the MAF g/sec dipping right before the knock shows up, but again, maybe I'm correlating something (tiny dips) that is normal to chasing my knock issue when there really is no relation.
@kbuskill - Do you happen to know how many degrees total Lew ended up pulling out in the upper RPM's when he did your custom tune? This being my first venture into tweaking an LS based motor, I don't really have a basis into what is a lot or a little amount of timing. I'm up to pulling 6 degrees from 4000 up right now which to me "sounds" like a lot, but maybe it's not that abnormal.
This is from this morning's log during a WOT pull. Again, probably me finding connections that probably aren't there, but it just seems like a pattern.
1. MAF dip, knock up.
2. MAF recovers, knock down.
3. MAF dip, knock up.
4. MAF recovers, knock down.
View attachment 214629
He also told me to make sure there was nothing loose and tapping on the engine or exhaust, like a heat shield.
He said the knock sensors are pretty sensitive and will pic up that kinda stuff.
Yeah, it isn't very much when it dips on yours, or mine really for that matter. Just maybe 5 or so g/sec for a split second then recovers.
I have no idea to be honest. Like I said, the highest I saw the timing advance go on my WOT run was 19°.
Maybe that's just airflow. On my MAFs from the 1980s the air went through a honeycomb to smooth the flow out but this '09 doesn't have that anymore.
On that run of mine posted up there, the timing at WOT was 29 degrees.