[blackbeast06]

The other day I was cruising at 120mph and I kept feeling what I would describe as a small boost increase every couple seconds. I am not sure if I just could not keep the pedal constant or if some how I was getting surges of boost. It was just like little blips of power while at a constant cruise. Mods are JB4, dp's, dci. This was on a private tarmac, not public roads. Has anyone experienced something similar to this? I have not had time to run any logs.

[JamesM3M5]

Sounds like lean surge. Could be old pre-cat O2 sensors. But without any data, it's hard to say.

[marv85]

Could also be you're dropping timing on multiple cylinders and then recovering..

Like James said, you need to log it so we can help

[blackbeast06]

Here are some logs before I noticed the issue. Firs one is right after I put on the dp's and the second one is with E85.

[marv85]

Those stutters you have at 120mph, was it when you were running E85? If yes, then James is right, you're going lean. Actually I bet on it as my friends has your setup and was seeing the same issue. I drove his car once at the track I got the exact same thing you were describing.

On another note, you have timing drops. Meaning the tuning is aggressive for what your setup.

[blackbeast06]

The surges of power occurred without e85, I never did the high speed run on e85 so not sure if they could have happened then also. AFR's are 12.8-13 so I guess that is a little lean. Can I adjust this on the JB4, I am running map 5 so I though it would be ok. Maybe I should run map 2??? Or maybe an intercooler can help correct this issue.

[marv85]

Intercooler will help with timing probably (even though I don;t see your IATs in the log) but not with AFRs.

AFRs can be tuned on the JB4 GUI however I am not the right person to ask on this regards I'm sure the JB guys can help on this.

Although you seem to be low 12s on the run with no E85. It's hard to read the plot so correct me if I'm wrong