22 G42 M240i
 

Hooked up the JB4 today and cruised around on map 0 for a while to get a few logs for base line. Fuel is 93 w/ 2-3 gal E85. Tested out map 1, logs show lots of timing being pulled and boost at 20-22. Decided to try out map 4. Boost is more controlled and it has a little more timing, but the ol butt dyno feels like map 1 has more punch.

So the question is: additive maps vs absolute, what is better? Pros/cons?

I guess I could always give them q few days to adapt and dragy it out, but looking for advice/info.

Thanks!

Would need to see the log for tuning advice. Generally map2 or map5 on the Gen2 B58s though with a mild E85 mix.

Thanks for the reply. I was looking for general info on why choose additive over absolute or vice versa. I'll also attach some logs from the last few days.

Is it just IATs that are killing me here? The map 4 runs got worse as the IATs went up. Thanks again!

You need to update your firmware and do proper logs...do not edit them!

Firmware updated and I will post a few logs of different maps. I switched from map 4 to map 2 and its running like a champion. Ran a 11.35@120.2 1/4 mile. Was also able to clock a 3.18 0-60. Thats almost G8x xdrive times!

About the logs. the beginning of map 2 log is me letting it learn. Good runs start at 361.5. 3 good runs. The map 4 logs seem to start good and get progressively worse. The 3rd qtr mile log looks like a monster!

Here's my questions:

1. Why choose an absolute map over additive?

2. For the boost shift redux, do I want to go up or down for quicker times?

3. Do the fuel trims max out at 50?

4. Would you recommend using the lag fix setting?

Odd that map 2 feels better...map 4 looks better with more boost.

Yes, trims max at 50 and lowering boost reduction is faster.

I guess ill switch to map 4 and just dragy it out. If you looked at the map 4 log you'll see that by the end of that log its pulling a ton of timing.

I did a 0-60 run on map 4 and hit a 3.41. Got a 3.18 on map 2. Was also a warmer day than when I did the map 2 runs.

Any input on lag fix setting?

Switched back to map 4 today and it seems to be pulling hard before backing off then pulling again. Looks like fuel trims are maxing out. I even put 3 gallons of straight 93 into a 1/4 tank just to make sure I wasnt running too much E. I put 2.5 gal into a full tank previously, so should be E20 or so, but added more 93 as a precaution.

Still pulling power. You can feel the car oscillate under WOT. Not linear acceleration at all. Anything I can do other than switch back to map 2?

What is the capacity of the fuel tank in the m240i? I'd probably do around E22-25 just to be on the safe side. I usually do 1.9 gallons E85 and 6.1 gallons 93 for a half tank or 3.2-3.3 gallons E85 and rest 93 for a full tank (this is in my G20). That helps timing a lot.

The throttle closures are killer. Try map 2 with that same ethanol mixture. Just to make sure, is traction all the way off?

0-60 is not a useful matrix for comparison...too many variables.

You're getting boost oscillation...do you have the EWG wires installed?

Map 2 runs great, logs above. Traction is in traction mode, which im pretty sure is traction off VSC on. the car is AWD, fairly certain its not a wheel slip issue.

Yes, the EWG connections are installed. I filled the tank with 93 today and it seems to be figuring itself out. Not sure what may have been going on. The most E I ever put in was 2.5 gal into a full tank. Maybe it just had to unlearn whatever adaptations it had learned from map 2 before it could run map 4 and be stable. I'm going to give it some time to learn and take some more logs over the next few days. Here's todays that show it coming back to normal in the latter half of the log.

Just kidding. Its still maxing trims and oscillating boost. Popped the hood and checked EWG connections and everything looks solid. Logs attached. What's the way ahead here??

Thanks!

Any help getting this sorted?

Your trims are maxing out and forcing you lean so you'll have to reduce the ethanol content.

The log looks okay otherwise but still a bit of oscillation which is odd. Try lowering your PID gain to 15, set FF to 60 and do another log on map 4.

Super weird because the last 2 times i got gas it was straight 93 with no additional E.

Will do! Just for my own knowledge, mind clueing me in on what PID gain and FF are? or if there is already a guide where it is?

Appreciate the help!

Here is a list of all logging parameters and their meanings. Please let us know if you have any other questions!
https://www.n54tech.com/forums/showthread.php?t=21269

Awesome thanks! Exactly what I was looking for.

:happy

Is there a way to reset the JB4 learning? The car was running good, but has gotten progressively worse. Now even Map 1 is acting up. Reset FF back to 50 and PID to 20, which are defaults correct? The car has not had any E85 in weeks at this point. Ran at least 2 tanks of straight 93 through the car.

When I do a run the car pulls hard for half a second before it falls flat on its face. Runs are done with TSC fully off. Is the throttle closing due to overboost from an upgraded DP? I'm running an AA catted. No CEL. I'm at a total loss for what to do next.

Appreciate the help!

I think you keep switching too many variables. I would reset the jb4 back to default settings, put the car in map 1 or 2 and do a log then. I wouldn't start messing with other settings like boost shift redux until you get the standard map dialed in.

Put settings back to default and record another log.

The ECU is dropping it's target which is usally form older ECU software running E85 mixtures. With no E85 in the tank I'm not sure why it's doing that. Do a map0 log to look at DME BT for comparison.

Here's map 0. Nothing appears out of the ordinary, at least not that I notice.