Current parameters are from Aaron Cakes "Programming the ECU (MS2)" intended for same size primary and secondary. Aaron suggests that the table may need modifying when much larger secondary injectors r in place as in my setup.

Yesterday and today, while doing a VEAL session, things were going just fine until I suddenly hit that wall of too rich a fuel shot and the AFRs pegging max rich. Last cell to get updated is shown below at 4500 rpm and 100kpa. Must have happened as it approached 5000 rpm. I've never moved my foot so fast!



Thing is staging should have already begun at 4k rpm and 80kpa. So, it's a head scratcher as to why the ECU decided to dump so much fuel all of the sudden.

Can someone please suggest/provide a sample of how the staging table should be set up?

Thx much!

 

you need to adjust your stage table.

 

ElTurboNitroso,

Do you have a suggestion what changes to make? Thx..

 

i would adjust your 100kpa bar and make the 110kpa bar 120kpa and start making adjustment again.

 

If you can safely do it (spring pressure for wastegate, maybe need to set a limiter by rpm or MAP just in case), set the entire staging map (all speed/load points) to run on ONLY the primary injectors. Slowly and carefully collect data at the different engine speed and MAP points in the cruising range. Use higher gears so that you progress more slowly, so 4th or 5th if you can. Lug the engine if needed. Also zero out your tip in fuel so that is basically turned off or significantly reduced. The important point of going slowly/lugging the engine is that it will reduce the impact of transient fuel, sample rates, banging through the gears, etc. The most important thing is you want to configure your VE table and your staging according to the "steady state" of the engine, or as close as you can get it. Once your AFRs are adjusted in that way, and your primary injector duty cycle is characterized, you can dial in the tip in fuel and the secondary injector staging. Lots of hours on a dyno would be ideal, but is of course cost prohibitive. Most likely you will need a road with low traffic and a lot of time. It sounds like you are already starting with VE tuning, but I'm not clear how you are going about doing it (what drive cycle etc).

You will need to generate multiple data logs and come up with some kind of averaging. Maybe have an assistant watch the logs in real time while driving and record a reasonable averaged value. You should create an Excel table of RPM vs MAP that matches your table breakpoints. Figure out where you are hitting say 60, 70, 80 % duty cycle on the primary injectors only and how that corresponds to the breakpoints. These will help determine your staging map. Post the results here. Take that data into consideration as you adjust your staging map. You really want to go at maybe 80% duty max, but you also don't want to dump in fuel. The whole point of VE maps is to figure out how much air the car flows at some baseline condition, and then if all your other tables are correct the ECU will do the rest of the calculations for you (water and air temp compensation etc).

Otherwise if you don't characterize the engine up front you get into a chasing-your-tail pattern, with staging and tip in fuel and VE tables (maybe air temp and wideband feedback/closed loop) all fighting each other. That doesn't mean you can't "guess and check" your way into something tolerable - but it's a real uphill fight to just go and make small changes to somebody else's base map and hope for the best.

So the work flow goes like this:

Primary injector only / no tip in fuel - map the engine to the target AFR / adjusting the VE table , up to the limits of the primary injector duty (lot of slow manuevers at high gear or on loading dyno)
Figure out tip in fuel at low loads
dial in staging once you've figured out where the primary's are running out of duty cycle
adjust air and water temp compensation as needed (long term process)
set up closed loop fueling at low loads
make some spark changes to whatever safe basemap you're using

Actual heavy boost/WOT tuning is way later. That's the easy part. Or alternately, you do that first, the car can go WOT under some conditions and runs terribly/dangerously in all other conditions.

 

ARGHX, thank you very much!!

Questions: What is Tip In Fuel? Also, under full throttle, when the secondaries come in, do the primary's DC stay fixed as RPMs increase?

So, I have to figure out how to log/plot RPM vs MAP vs DC.

How am I VE tuning? Waste gate actuator is currently disconnected. I come to a stop, start the TunerStudio's "Tune Analyze Live! - Tune For You" (aka, VEAL) and gradually bring up the RPMs once in 3rd gear while making sure it doesn't go into boost. The up to 1500 rpm and 70 kpa is blocked from VEAL making changes. I've done 4 VEAL sessions bringing the RPMs to just above 5000 RPM. I have not yet generated a log. So far it has been to get a feel to how VEAL works and to see if the numbers change between sessions. This last session, VEAL updated with lower values.

Might be a while before I can post results. My house here in FL is going up 1st of next month. Will be busy preparing for the move to our new home in Prescott Valley, AZ. In all honesty, once in AZ, I've thought of trailing the car to Corona, CA to have Abel Ibarra tune the car. Have realized to get a proper tune is no easy task.

 

Tip in fuel is acceleration enrichment tables. Depending on how you have it set up there is compensation based on the movement of the throttle or the change in MAP, or a fuel film model (called X-Tau). If you're not careful it can interfere with the data collection. The engine is dumping in extra fuel because of how quickly you're moving the pedal.

All of these auto tune type functions are useful but as you said, every time you drive you're going to get slightly different results as air temperatures change etc. I wouldn't try any of it just yet. Just take datalogs with what you have right now, to figure out what your injector duty cycle is on the primaries. If the "wastegate actuator is disconnected" then you have no boost control?(!) The wastegate doesn't open? You should have overboost fuel cut and wastegate running, at least on spring pressure without a boost controller.



To be honest, I'm not 100% sure as I'm not finding good documentation on how the staging calculation is done when the map is not at 0% or 100% and I don't have any recent logs from a MS. I'm assuming 100% means the primaries are completely turned off, and the required fuel is completely assigned to the secondaries. It's not necessarily capping primary duty cycle and then adding the rest of the fuel from the secondaries. How it calculates in between 0 and 100 in the staging map, well maybe they take required fuel, the fuel delivery of each injector according to size, and divide it up (mass-based approximation). Somebody else can chime in, I get a lot of tuning questions on different platforms and I can't keep all the details straight.

The nice thing about going to a shop is they have a lot of equipment and previous experience, and a lot of understanding of how the work flow goes. The disadvantage is that they will not be able to do a lot of the grind of driveability tuning due to not having the time / getting paid by the hour.

 

I meant to say the linkage to the wastegate is disconnected. The flapper is free to move. And it will still develop boost if I put the pedal to metal thru redline.

Regarding primary DC, I always envisioned, and made sense to me, iff both the primary and secondary are same size, when the staging occurred both would get the same DC but cut in half. I've added to the gauge cluster both primary and secondary DC gauges to see what happens when the secondary kick in. I don't think I have the ability to log those parameters, at least it's not obvious to me.

It may turn out like you suggested that once the secondary kick in the software lock the pulse width on the primary.

 

Going to try these settings. Will have a copilot observing the DC gauges as I rev it towards 6k while VEAL is running.

 

I would make your 110 kpa and RPM 5000-70
6000-80
7000-90