2014 V6 mustang procharger stumbles/sling shots at 2.5k rpm

[basshed]

I made a small change to the Driver demand tho mostly focused on cleaning up the torque/torque inverse. I also was starting to see some extensive short trim creep at WOT so I knocked that down 1% in the mass transfer. The thing I noticed subjectively is that I can feel in the throttle when the torque table has a dip in it - likewise I think that relates to if I cross over a big enough dip I get that hard torque cut. So I worked on making the torque table transition as smooth as possible between the IPC error adjustments from the last set of data logs I made. So here's the result for tomorrows drag test n tune. This is definitely an improvement from before. Idle is still occasionally hunting but that seems to be driver demand which I can work on this weekend.

added a follow up log for the new tune.

[murfie]

As you get it more and more dialed in you can require more cell hits in the graphs to get more accuracy and reduce the obviously wrong ones. You can also right click on the PID and change the polling speed for the specific PIDS in the graphs so they get an update every 10ms instead of 200ms this will increase the cell count and help get the cells that you just can seem to get good data for. Then you can start finally bracketing the cam shafts and get the most flow out of the super charger.

I also think if you log "accelerator pedal position D" while modding the DD table you will be able to convert to the ADC value better. You could also use "pedal position sensor 1" voltage and convert it to ADC by (ADC resolution*measured voltage)/ System max voltage= Current ADC. (542*PEDAL position volts PID)/5v

[basshed]

Thanks for the ideas. I'll be pondering over them this weekend. I was trying to think of a way to refine the pedal position vs that scalar of 542. Good stuff. I was able to make 3 passes at the strip last night and got a limiter at the top of 1st in 2 of them. Not logging at the time but it looked like a rpm fuel cut from the gauges. right at 5k after a hard launch it would go into limp and than on 2nd gear nearly snap the car sideways. best time was a 14.1 @102 but the other two were more consistent with the bad run a week ago. 14.6@101, 14.5 @100 and 14.6@101. 60ft times were atrocious on all of them at 2.23x on a car I've gotten 2.1x and better out of so it's not getting up on the tire at all. When I ran a few tests on the street they both pulled to red line in 1st - which makes me suspect the tune isn't accounting for track prep with a small burn out. There wasn't time to try a launch with no burn out as there were over 70 cars there. Great night for racing. This is a 6sp tremac magnum so not the shift limiter like the other thread but it feels the same - it doesn't want to rev out due to seeing some discrepancy between torque and wheel speed? If I could get a full 1st gear pull I think there's at least a 13.3 in the car the way it pulls in 2 & 3rd.

[murfie]

looking at your last two logs I noticed your engine brake torque spikes right at 5000RPM. It actually passes engine indicated engine torque right after 5000RPM. This could be the cause of your limit. I think if you work on getting the load values in your inverse tables up to 1.2 or more you will eliminate this limit.

5000rpmv6pro.PNG

[basshed]

I'm starting to see how this works a lot better. I was questioning myself about leaving the inverse at 368 tq but couldn't think of a reason the car would have an issue with it. But now that you show me that image I can see how it is trying to limit the car to 1.0 load at WOT because it doesn't have complete data out to 1.2 load in both tables. The better the car grips... such as in 2nd and 3rd on the street at 3k or in 1st on the strip, the higher the torque reads and the less overlap the tables has. So based on this info the logs show that the car will take the lesser of the two values and force a torque cap to meet it. so at 5k we have a cap of about 1.04 which is 250tq. Easy to fix: here's the updated inverse scaled out to 1.23 load at 6750 rpm.. then the numbers in the column are equal parts by .10 down and recopy the whole thing into the tune.

[MMGT1]

P1 I've been into is seeing loads of 1.36 and went to 1.4 load for tables. Might want to just go to the 1.4 now because when you get this all worked out I would imagine you'll be in the same place. Manual, 2013, P1, stock suspension, curb weight, and 19" wheels ran a 11.9 at 117 two weeks ago.(V6 lifting 19" wheels into second is pretty dam cool in my books)Dropped in a 3.2 pulley just yesterday and adding a wastegate. I don't see why right now we wont get a mid 11 out of this car, and a low one with biggs and littles.

[basshed]

The car is indeed much more potent with the inverse extended out to 1.23. I saw load of 1.21 and right at 8psi boost which is the highest recorded since starting this process. 1st gear on the street is gob fulls of wheel spin above 3k and I never hit that torque cut in any of the stop and go driving. So that's a win. Here's what I don't get. There's about 40ft-lbs difference between brake torque and indicated torque still. I suspect that is related to the driver demand being low. So, new idea to find the ratio off like was discussed for driver demand --- but between brake torque and desired torque and rescale to the 330ft-lbs it routinely reports in the 5000rpm+ range. What do you think - good way to do this or no?

[murfie]

Yes you have it right and guessed my next step to get the brake torque and indicated torque closer. The driver demand will not do that as it is the desired torque. you would need to apply the correction in the indicated torque tables and maintain the load in the inverse tables. as MMGT1 mentioned you may start to see even higher loads as you add the appropriate amount of torque. you are right that the driver demand could be modified to increase the load from the throttle body calculation and allow the indicated torque to increase.

[basshed]

Bumping indicated torque by the ratio to brake torque had negative results. MP's started showing huge errors in places previously fixed - subjective evidence of the torque hesitation crossing 3k rpms started up again. The discrepancy between indicated and brake torque grew to 80 ft-lbs. So going back to the last tune for now. I really feel that the desired torque is the culprit in the driver demand table but want to run it by you again. Did this behave as you expected. I really appreciate all the great patient support you've provided. The car is really a joy to drive now & the power is about what I expected even with these little issues still to sort.

[murfie]

Yes desired torque is the culprit. Brake engine torque increased but indicated engine did not when it should have, so you know the engine is being limited. desired torque is driver demand and ETC torque is the throttle body data. This is limiting the load for the increase in the torque/inverse table to be effective. You can really see it with how much less your ETC effective area became. You want to increase both scheduled and indicated engine torque by way of torque/ inverse tables and desired/ETC torque by way of driver demand OR ETC model together. Driver demand is the more reasonable table to modify for driveability as you don't want to tell the ECU your 5IN^2 TB becomes a 7.5IN^2 TB to increase load available. If you apply more to the driver demand and not the torque/inverse tables they will limit the engine brake torque. you kinda want the engine brake torque between the DD and TQ/inverse, then increase until the brake TQ starts to fall towards the DD. You don't want it below the DD except for idle and decel. this causes error and the TB to close.

Just keep an eye on all the IPC and other tables that can limit torque/MAP both in the engine and transmission.

[basshed]

Happy to hear we're on the same page on this. What clued me in was the ETC error was at least -20* or greater at WOT which is the same as the effective are being impacted. I'm going to run the old file for tomorrow. Too late to fiddle with it and the smooth power delivery is really the important part for autocross. But I'll then go back to the number 7 file as the next step and bump DD and log if it moves in the right direction. and then keep refining from there. I agree there's a lot more power to be found but growing into it is actually better. takes a real smooth foot to manage it already.

[basshed]

I'm lost at the moment. I raised driver demand to meet engine brake torque and rescaled to 1.4 load. This was from the number 7 file. What appears to have resulted is the two flip flopped. desired is above brake torque. And indicated went up higher than ever. So etc effective area is really high but the MP tables are pretty happy. Which chart needs tweaked to bring brake torque back above driver demand? I think this is going the right way but it's more choppy than the number 6 file, this set up hits that 3k rpm torque limiter a bit. tho this is still way better than the brick wall feeling from pre-#6.

[murfie]

I noticed from your changes that the desired air mass and MAF have as swapped places. Try doing what you have been doing with the desired/ actual torque with desired airmass form torque control /MAF value. apply the correction to the DD table and get the MAF and desired air mass from Torque synced up. These pictures show the difference of des MAF and MAF and the effect on load. I think I see why 6 felt the best as they were the closest.

ADJ8
adj8.PNG

ADJ7
adj7.PNG

ADJ6
adj6.PNG

[basshed]

That idea made the most sense of what I was messing around with. I knew DD needed to come down a bit from where it was and this log bears out that was the right tweak. The down side is mapped points got really unhappy in the boost areas.. especially where I was able to vary load at higher RPM to fill out the chart. It's really interesting, the more we dial in DD the more active all of the Mapped points become instead of just a few hits in each. Pondering --- does the high numbers in Mapped points mean that indicated torque/inverse need raised or that they need to also be reduced? Forgot to mention that this did drive better than 6 except where the Mapped points are out of sync and that was more of a stumble on decel than the torque limit on accel.

One of the items I'm curious about is air flow - with these changes the maf is now seeing closer to 40lb/min of air which is good to see. but it's not quite coyote territory. but that's apples to oranges and I wonder if the car is close to tapped out or can it be tweaked closer to 45lb/min - is that being risky? What sorts of things does a log show when it's close to tapped out and needs backed down?

[murfie]

The mapped point activity from getting the DD dialed in I find to be a good thing. It means you are hitting a limit or reduced power mode. In your last log around 6100RPm I saw a trans truncation limit. Raising the torque values in the transmission may be needed. in this log I see weight from the OP going to MP 11 and 9. I find MP 11 and 9 comes in to play only during emissions reduction mode. After you pulls I see CAT over temp enrich. This could be causing your decel stumble and a reduction in power
during the pull. few options here. get headers shut this off, Add fuel at WOT and more timing(this is playing it safe), lastly raise the COT temperatures, with the load you are seeing you may not be able to raise it high enough. These temperatures are inferred from load vs RPM you can lower the values in this table some to raise the COT limit but not disable it although you kind of are disabling it because it is inferred. First you can try zeroing out your emissions reduction distance table and see if that helps the MP weights.

Not sure if we tried this, but, now that the TQ tables are better returning ETC idle throttle angle closer to stock would also help on the decel stumble. Atleast get it to close the TB to hit more of the negative values of the DD during decel.

The good news is after dialing in your DD tables I am no longer seeing knock randomly and during TIP in. I noticed your knock advance limit is zeroed out. This is for safety while dialing it in. You could put in 4 or 5* in that table and see if you get any more timing out of it. My guess boosted you should see 14-16* your only seeing 8-11*. Your MBT tables in the higher loads could also be lowered down closer to the borderline tables.

I have not done any research on the physical limits of the V6. I would just watch knock retard and see where your ignition gets too and don't let the wide bands go too lean. 8 or 9 PSI should be ok on a stock engine. You mentioned you have a good trans and clutch so shouldn't need to worry there.

[MMGT1]

We ran 12.21 @ 116 on 18* timing and .78 Lambda. Stock with kit pulley and no meth, manual(31 passes in 3 and half hours) Belt was slipping a bit but he was seeing 8psi.

[murfie]

We ran 12.21 @ 116 on 18* timing and .78 Lambda. Stock with kit pulley and no meth, manual(31 passes in 3 and half hours) Belt was slipping a bit but he was seeing 8psi.

Are you seeing over 45 LB/min MAF? whats your exhaust setup?

[basshed]

It's raining so no tuning tonight. 9 gets better the more I drive on it. I agree that advancing timing back up from 10 is logical for next step. And massage these other limits that are popping up.

[MMGT1]

It hit 47.3 lb/min in the pass that got 12.21. Couple of weeks ago it ran a 11.9 three passes in a row. Times were almost identical in all three, within .02.(This was with the meth kit installed)Mac equal length shorties wrapped and a cat back. Cats and mid pipe are still stock.

[basshed]

MMGT1 thanks for the reference numbers. I think I'd be happy with 45lb/min at this point. I tinkered with the items Murfie suggested plus looked at the idle lope some. Too much timing down low really makes it wonky. but if jumps up to high into other areas it makes it sluggish to pick up speed out of a shift or rolling into 1st gear. Something to fiddle with later - I think smoothing it will allow it to have low timing at idle and ramp up smoother. The log and file I'm posting are pretty good but be aware I could not get traction above 5k even in 2nd. 200tw tires in 50* temps plus pushing close to 42lb/min was a handful - it stepped out a lot and I'm sure advance trak was stepping in to help keep it straight. I don't have as clean pulls as last couple logs. But hopefully they tell a tale. I messed with throttle body a bit but wound up putting it back to stock. too much high vacuum throttle would cause it to hang. too little throttle angle would cause it to stall - I might try a hundredths of a change. we're talking tenths of a change tonight. I'm also seeing rpm hang at 5k if I clutch in at that speed and try to let it rev down it won't without grabbing a higher gear. Which one of the histograms I made painted the picture of it wanting more throttle at idle and less up high but it's really sensitive to tweaking the throttle body. ideas?