• Posts

  • Joined

  • Last visited

  • Days Won


Posts posted by S70-R

  1. 5 hours ago, Piet said:

    Well...one of the other advantages of the widebandmod is that you can run an AFR at idle and light load (cruising) other then 14.7.

    The original narrowband control will always push AFR to 14.7 no matter what values you fill in the VE-table.

    An AFR of 14.7 is only benificial for the catalytic converter. The engine on the other hand performs best at higher AFR's at light load.

    And running higher AFR's at light load improves mileage.

    Absolutely true! Those are the main reasons why I would (or likely will at somepoint) use the wideband mod ;)

    Filling the VE table and hit the target straight away is also awesome, for sure!

    My point was just to show that even without the wideband mod it is still perfectly possible to get a good AFR control although it takes more time and it's never as accurate as with the mod. And because, being honest, a 0.2-0.3 AFR variance will not hurt anyone or any performance target by noticeable amounts.

    9 hours ago, NB-V70R said:

    Has someone done this already? If not, I am willing to give it a shot to try and prove/disprove this theory for people who can't have/don't want the full wideband mod. Someday I hope to implement it, but atm I have a lot of learning to do.

    I did. I've never used the wideband mod so far so I've been doing that since the beginning. I think most of the other members with a wideband gauge have also been doing that.

    It's not rocket science. It is something easy, logical and intuitive.

  2. 10 hours ago, Piet said:

    The biggest advantage of the wideband mod is that AFR is regulated in closed loop all the way to max RPM

    With it you can pin down the AFR you want.

    Changing, for instance, ignition won't have any influence anymore on AFR. Makes tuning easier.

    Yes, sure. No doubt about it.

    Just said that even without the wideband regulation mod, the VE table is still an AFR target table and that the system is still able to achieve the target AFR in open loop with a 0.1-0.4 AFR variance, which is not that bad anyway.

    And if we do some runs, log the achieved target AFR, match it with the target AFRs on the table we can measure the variance and then adjust the VE table further to achieve our real target AFRs.

    It's a bit more time consuming of course and it's not so accurate as the wideband regulation mod but it does its job.

  3. I also haven't ever touched the wot enrichment table. That table enriches or leans the mixture indeed but it does from the VE table values.

    Use the VE/lambda table only. Values of 1 mean stoich target (14,7 AFR). Values above 1 mean richer than stoich and below leaner than stoich. It's like inverted lambda values.

    So, this means you can know the target AFR values included on that table by doing the following math:

    1/x*14.7 being the x the VE number on the table. That formula outputs the target AFR for a specific VE number on the table.

    Actually, you can easily turn all the table into a target AFR table by changing its conversion formula in the xdf definitions.

    Put this formula:


    If everything is well calibrated (MAF and injectors) and if you have no vac/boost leaks the AFR you will get should be close to the target AFRs on the table. It may differ by 0.1-0.4 AFR.

    To get extremely accurate AFRs you need to use the wideband regulation mod.

  4. 16 hours ago, Avinitlarge said:

    At the weekend my friend is converting his 854 to M4.4 and is fitting a 2.4 NA engine. Will there be any issues with the 608 bin? He is leaving the TCV plugged in as there is no option to turn the diagnostic of for it.

    I believe it should run ok provided you disable rear o2, sas, baro sensor, etc.

    And of course ignition map should be custom made for that car.

  5. I had already noticed different TPS values when logging with tunerpro or when using for instance OBDII with Torque App but I didn't bother with it that much.

    But actually the ADX file seems to have that error on the conversionf factor.

    However, and at least on my adx file, when I'm on trace mode and when I'm looking at the TCV/target load tables the trace is stuck on the first column (TPS <=25). The trace just bounces up and down in the first column according to the RPMs.

    I noticed it is missing the X Axis DA Link but it seems I can't put it ok.

  6. I still see no need for that for 2 main reasons:

    1. When you are tuning a new setup for the first time, specially a bigger turbo, you should start with very low TCV duty cycle and then you will start to raise it slightly. This way you'll have no boost spikes for sure and you are able to get the TCV settings properly, unless you are running a much stronger WG spring than you really need (in that case you can run into boost spike no matter what TCV duty cycle you run).

    2. The stock ECU can do the trick for boost cut / fuel cut. Just get a MAP sensor and feed the signal to rear O2 channel for instance. Then, make a routine to set a boost cut or fuel cut if boost is higher than X limit. Doing this routine is the hardest part but the code contributors here would be able to do it (although is probably not needed).

    Other 2 ways of doing this mechanically (i.e. cut/limit boost) is to either use a parallel MBC or a turbo fuse along with a BOV/Recirc valve.

    And remember that the main cause of a rod failure may not be the boost spike itself but the ignition advance actually (which may lead to knock). Reducing ignition advance would be the first thing to do to prevent an engine damage along with boost cut/limit.

    Also to remember that the stock bin has load limits which can be / are used for boost cut.

  7. From your post, I'm a bit unsure about the purpose and goals you want with that.

    If that solution is to overcome a maxed MAF, why would you go that route instead of upgrading with a bigger MAF?

    Plus, a MAP (density) system is not that simple. It would require more than that I would say, such as manifold temp sensor, a real engine VE table, etc.


  8. Check if you have no boost leaks and your wastegate actuator preload.

    You can also disconnect the vaccum line going to the actuator and then carefuly go for a ride to see if you can build boost earlier than that.

    If you do this test please be careful as you'll have no ECU boost control. The turbo will freely and fully spool. Don't go WOT, just mid throtlle or something like that.

  9. Detect detonation before it happens is virtually not possible.

    However, if you are a good in chemistry, physics and math, and if you are able to collect some data such as cylinder temps, IAT, density of mixture, etc. you can probably calculate the optimal ignition timing before detonation happens.

    This is however really difficult and or inaccurate to calculate I assume so the best option is still by finding the knocking point, either on a dyno or in the road.

    Dyno is better to optimize all the ignition map but it has some problems with higher IATs. On the road the IATs tend to be lower and so the knocking point will be higher.

  10. From what I understood about Tmm9 post, D394 is a map -> "length 16 map at 0xD934 is used."

    TMFWLO is a temperature set point at C922.

    I already configured the temperature set points on my XDF as well as the load 8x8 map at 0xDDC4.

    Just would like to understand if the map at 0xD934 is a 16 rows or columns map, what is the axis and the conversion factor.