Need Help Tuning


New Member
Jul 1, 2020
I honestly have no clue where to start this. I've been trying to self tune my N54 for a little and I cant ever seem to get everything right. Added fuel, saw the decrease in afrs (from 14-13). Did a few pulls and it felt good with no timing correction. Bumped up each load target table by 10. Did a few pulls and misfire CYL 3. Clear code and everything is good. At that point I thought well lets see if someone else tune will react the same, or if it was a part issue. So I decided to try out RFP's stage 1 v12 OTS tune. It felt strong but some parts I was leaning out, around 1.5k rpm at no boost I was getting 17 afr for half a second. The car still felt strong and was hitting 13s afr during a pull. Logged a few pulls, and when I went to go and check them, afrs looked good during the pull and no timing correction. There was some timing correction during normal driving but it wasnt while in boost, which is normal so I don't think anything of it. So I made a mental note to add a little bit of fuel to the tune before I go out again, and from what I see it did drop down to 16s at 1.5k RPM. At the same time that tune is very aggressive. It would go from 0-1 lbs of boost to 8 or 9 within 200 rpm. So I thought I would try and fix this myself. Load is set at 185 at 1775 RPM and 1900, so I set it 175 and 180. When I went to go and test it today I was getting timing correction during the pull. Which now just confuses me. Its pulling timing when I ask for less boost. I probably am doing something wrong but I just dont know what it is. It's really hard trying to navigate through something you barely know.

I've tried to reach out to Motiv and Twisted Tuning to see if I bought their custom tune if they would work with me and help, no response from either.

Also. I just looked back at my tune and my load targets are different, Load Target is 175,180,185 and Load Target (AT) is 175,185,185. From what I understand thats a table for Automatic Trans and it shouldn't have anything to do with the tune for my car since its a manual.

I know I sound like an idiot, but this is something I've always wanted to learn and now I have a chance to.

Ill have to look through all my logs but here are 3. This is the original RFP tune then with me adding fuel and then with me adding fuel and less boost.

Any help would be awesome.

I posted this on bummerboost also, because im taking all the help I can get.


Oct 10, 2018
BMW 135i
N54 also has a lean spool feature, you should check if it is enabled on either yours or the RFP tune. On my car when this was enabled (stock settings) I would see 16-18 AFR while spooling. If the factory set it up like its probably fine, but I turned mine off and it spools following the spool AFR table now. Its under Toggles > Functions > Disable Lean Spool. Set to zero to disable lean spool, set to 1 to turn on lean spool.

How are you adding fuel? If you're using the "Fuel Scalar (Bank 1/2)" tables, it will trim the fuel back out using the O2 sensors. You should use the "Fuel (Bank 1/2" tables to choose a new target AFR and the ECU will add the correct amount of fuel to get there. The Fuel Scalar tables are used to add or remove fuel in areas where the fueling is not accurate, which you can see by watching the fuel trims. Areas where the fuel trims are more than +/- ~15-20% would probably want fixes in the scalar tables. Direct injected engines don't like to run as rich as the older stuff, you may not need to be adding any fuel at all.


New Member
Nov 28, 2020
If I recall the V12 maps had lean spool on, or used main table as the reference for spooling with very lean afr.
Reference the RPM and STFT at the same rpm/load if it is above 5%, go into that area in Fuel Scalar table (RPM/ LOAD) and add few points in 0.01 format to the table. Follow through the range


Jun 17, 2018
Sounds like you have a vacuum leak to me. BOV spring is wrong/weak, line to it leaks, didn't tighten the meth plugs, charge pipe oring is damaged ...

i don't see anything having to do with lean spool playing a part here. this is a mechanical problem imho

*edit: fuck, this is old and will do no good ...