Interesting I've done some datalogging also with 3.5 with just 93 and the most positive knock I got was .50 on just one log the others were averaging -.20 and below.. are you on the 10rib system or 6?I've done a lot of testing recently and found much more knock activity than I want. All test runs were done from 3500 rpm to my shift light activation at 7300 rpm from 3rd to 4th gears. Whipple calibration and used Ngauge to log the runs. I video the gauge is what I did and had boost, lambda, knocker, spark advance and true dedicated IAT 2 sensor which I installed. I cant say I'm completely happy with the knock I was seeing especially with the 11 psi pulley as 93 octane should make the knocker happy.
93 octane last summer 3.75" whipple pulley makes 9.5-10 psi 21 degrees advance no knock
The test below were all done within a 3 day period last week.
93 octane 3.5" pulley 13 psi 15 spark advance and 3-4 degrees positive knock
91 octane non ethanol shell 3.5" 13 psi 13 spark advance and s hit load of knock 4-5 positive:eyebulge:
93 octane top tear station 3.625" 11 psi 16 spark advance 2 degrees positive knock.
VP100 canned race fuel 3.3" 14 psi pulley 18-20 degrees timing and -2 knock
I also ordered some of the ACES stuff and was looking forward to testing it out. Was hopeful it would help me with the positive knock I'm seeing on the 91 we have in town. I'm seeing (edit - looked at logs again. There were some 6- 7s early on, latest tune revision is is rarely at 4* now) pos knock with the Chevron 91 in the tank. I've tried multiple stations around town and it's always been the same. When I put Race Gas concentrate in it the pos knock completely disappears and it goes all negative. I've been working with a new tuner and he's even dialed my advance back to 14 and the knock values are just as high. Really kind of a bummer. Wishing we had some 93 around here, but no such luck.
I'm using 6 rib. I was very surprised to see that much knock on a 3.625" pulley.
That's a lot of positive knock your getting, also what pulley you running with that knock activity?
I just bought ACES after reading about it here. Was hopeful but not sounding good from your tests. I noticed you added 2 ounces to a tank. When I spoke to Brian he said 2 ounces in a 16 gal tank wouldn't do much, if anything. 2 ounces treats up to 12 gallons and drops off like a bell curve after that. Just wondering if you added to a full tank or not? Thanks
I added 2 oz per 12 gallons, but during my testing tried 3 oz per 12 gal and it didn't make any dofference.
I'm not laughing:headbonk:
Yeah as far as I know it is a lot of pos knock. I sure wish I would have logged it stock on the 91, for all I know it was having pos knock bone stock. Wishing there was some sort of publication I could find from Ford on what knock values are considered normal in factory form, shit plenty of guys using 87, would be interesting to see something from the engineers.
What boost level do you see? So many things affect knock and timing advance. Gas inconsistency is a big culprit of knock logic being more active from one time to the next.
There isn't any inconsistency (lol) in the gas I can find, it all acts the same way at least between the 5 or 6 stations I've tried over the last few months.