Hi guys, I am pulling my hair out, I’m running Map 0 on the JB4 (stock boost) currently because I’m in Cali and can only get 91 octane. If I go up to Map 1 I seem to get bad pinging even with a bottle of Lucas octane booster in the tank. I just looked at my logs because the car feels a bit sluggish and from what I can see even on stock boost the timing seems to be pulled down to 0 on acceleration. This is all on 91 octane with a full bottle of octane booster????
It’s hard to say when the problem started, the performance seems to be up and down sporadically based on my butt dyno. Sometimes it feels fast and breaks the tires loose a bit on acceleration in first, sometimes it feels a bit sluggish. I just installed the JB4 a couple weeks ago so I could see some logs and figure out what it going on. Sure enough it caught what I expected to see with the timing. The fuel is the same fuel I’ve been using for quite a while. Here’s another thing, I had a jb1 before getting the JB4, I would run map 1 on 91 with the same octane booster and never heard/felt the pinging/detonation, then I got the JB4, now even if I try to run +2 psi on map 6 it pings like crazy even rolling into 1/2 throttle once boost kicks in.
As far as ethanol changes in California fuel I haven’t heard anything around here.
Set the JB4 to Map 8 and log a pull. Map 8 will pull boost down from stock. See if the timing advance comes back under low boost full throttle. That should tell you if it is boost levels that are causing your issue or something else.
If this confirms that it is the boost level and your AFR has looked fine at stock and JB4 enhanced boost levels, then I think it is likely your fuel. Do you have any E85 stations around you? Mixing in some high E content fuel s the preferred method of enhancing your octane vs a booster product. Looking back at the logs above, trims indicate you have plenty of fuel delivery.
Buy a $20 OBD2 bluetooth adapter and use your phone to log without the JB4 connected and see what timing does. Curious what octane booster was used as many of those are crap. You should be able to log with zero boost added still.
Yea I have a Snap-ON Titan unit that I try to monitor timing on also, I own a shop so we have some resources to work with. It's weird though because today I ran Map 0 and Map 8 and now the timing seems to be normal between 5-9 degrees. I'm wondering if when I try to run map 1 and it pings bad, that sets something in the PCM for that whole drive cycle to retard timing, so even when I switch back to Map 0 on that drive cycle it still retards the timing with the lower boost???
All of these look better than the 1st 2 logs you posted to the thread. Interesting, looks like valet mode only pulls a couple of PSI from stock...thought it might be more. That said, that log looks the best from a timing standpoint. It never drops below 5 except at a shift (which is normal). Even your map zero shows a normal looking curve, just lower than you would like to be. I would take it easy and work this tank of gas down as far as you can. Then go to a different brand top-tier gasoline retailer and fill up. Ideally If you can get any E85, mix 2-3 gallons in with the 91, that would be most definitive way to prove that your just having an issue with poor fuel. I don't know if the octane from a bottle stuff really works...I know it is frowned upon because of possible problems it can cause to the fuel system.