SURGING!!! 2016 Mustang GT W/GT350 Int., TB & JLT CAI

[Mark Hamrick]

My 2016 Mustang GT with a JLT CAI,GT350 TB & Int. surges while under load & seems to be pulling an invisible 500lb. anchor. I've been logging and editing the MAF Vs Period & if anyone would take a look at the log and tune files I would be very appreciative. I want to make sure I'm going in the right direction. MONDAY_02_07_22.hptMONDAY_02_07_22.hpl

[GHuggins]

Haven't looked at the tune, but did you update the TB settings in the tune?

[Mark Hamrick]

I copied a lot of TB settings from the GT350 tune. This seems different than that type of surge. This surging seems like fueling issues, maybe rich. If you hold the throttle steady like 1/2 or 3/4 throttle and accelerate in one of the higher gears it will pull pretty well at certain RPM's then at some points it just feels like it has an anchor behind it. While not moving the throttle at all it seems like you are moving it in & out slightly. i'm hoping it's just the MAF needing a little more adjusting. More driving, copy & pasting... LOL Thanks for any advice

[SultanHassanMasTuning]

did you route the vacuum lines or did you lock out the IMRC

[Mark Hamrick]

I routed the Vacuum lines but I do have a single popcorn sound when I turn the engine off.

[GHuggins]

Log all of your torque and throttle pids - error's included. Where I'm seeing it act up in the log the throttle is opening and closing rapidly from 40 to 60 %. You might want to try deactivating your runner controllers per sultan, but what I'm seeing usually only happens after adding boost. Looks like a torque model / dd issue. I tried finding my 350 tune for table comparison, but couldn't. Not sure where I hid it :/

[Mark Hamrick]

Thank you very much, I will go out tonight and get some new logs. Greatly Appreciate you

[GSLSE20B]

Frpp tune will set all your DD/torque tables correct for the T.B

[Grim5.0]

put the maf curve back to what ever jlt said it was. lock the learned baro to something reasonable for your altitude.

usually the learned baro tanks the etc vac and as it keeps adapting it drifts further and further south and IPC errors crop up etc.. or maybe its the etc vac tanks the baro.

[GHuggins]

put the maf curve back to what ever jlt said it was. lock the learned baro to something reasonable for your altitude.

usually the learned baro tanks the etc vac and as it keeps adapting it drifts further and further south and IPC errors crop up etc.. or maybe its the etc vac tanks the baro.

You've been seeing this happen on NA setups? I only ever see this issue on boosted setups causing them to surge.

[RobCat030]

You've been seeing this happen on NA setups? I only ever see this issue on boosted setups causing them to surge.

I think I read that the GT350 TB tables are not plug and play into other tunes. Retuning predictive angle and effective area may be necessary. If the new TB was the only change made that caused it, these are the only tables I would adjust. MAF and TTL certainly have not changed.

[Grim5.0]

im starting to adapt the same mentality. adjust what was changed and leave the rest alone.

na the gt350 tb caused the baro drift. it shifts the whole etc vac model so its pulling angles from an entire row higher than it should as it drifts. the frpp tune had a higher limit for what i believe was the desired air mass correction (suspect this logs as TB learned correction). it would adjust and keep things in check but the stock tunes have a limit at -98%. frpp tune would go past -200% and baro stayed within expected ranges. not a tuner/shop but this has been my experience hands on.

also, interesting that roush added an external baro sensor to the unused IMRC sensor on their gen2 kits in recent years. my own kit runs pretty much perfect although bit soft on timing which is simple to correct.

i havent ran into this with a boosted setup due to lack of experience. does massaging the tq table resolve? or is more needed?

[RobCat030]

im starting to adapt the same mentality. adjust what was changed and leave the rest alone.

na the gt350 tb caused the baro drift. it shifts the whole etc vac model so its pulling angles from an entire row higher than it should as it drifts. the frpp tune had a higher limit for what i believe was the desired air mass correction (suspect this logs as TB learned correction). it would adjust and keep things in check but the stock tunes have a limit at -98%. frpp tune would go past -200% and baro stayed within expected ranges. not a tuner/shop but this has been my experience hands on.

also, interesting that roush added an external baro sensor to the unused IMRC sensor on their gen2 kits in recent years. my own kit runs pretty much perfect although bit soft on timing which is simple to correct.

i havent ran into this with a boosted setup due to lack of experience. does massaging the tq table resolve? or is more needed?

Can you explain the baro drift? Is is going too low? There are different conditions for baro inference on the GT350, I wonder if bringing those over would correct the issue. Messing with desired airmass sounds like another way of sidestepping the actual issue, but it can always be disabled.

I'm still not really sold on jacking the torque model as a valid solution. Sure, you can basically create a "padding" between torque and inverse so that the IPC and torque feedback won't think twice. But is your car actually making a different amount of torque at any given RPM vs load? With boost the calculation for effective area is no longer accurate, that's the real problem.

[Grim5.0]

Can you explain the baro drift? Is is going too low? There are different conditions for baro inference on the GT350, I wonder if bringing those over would correct the issue. Messing with desired airmass sounds like another way of sidestepping the actual issue, but it can always be disabled.

I'm still not really sold on jacking the torque model as a valid solution. Sure, you can basically create a "padding" between torque and inverse so that the IPC and torque feedback won't think twice. But is your car actually making a different amount of torque at any given RPM vs load? With boost the calculation for effective area is no longer accurate, that's the real problem.

yep it drifts low. im 500ft above sealevel and baro with any external map sensor is usually right at 29.5inhg. if that was the last place the tune had learned the baro too, it will start there with the 350 tb and tune changes flashed and over the course of the first drive would start dropping. as it drops, it drives worse and worse.

what settings from the 350tune?

[RobCat030]

yep it drifts low. im 500ft above sealevel and baro with any external map sensor is usually right at 29.5inhg. if that was the last place the tune had learned the baro too, it will start there with the 350 tb and tune changes flashed and over the course of the first drive would start dropping. as it drops, it drives worse and worse.

what settings from the 350tune?

I'll PM

[Tadias48]

So did you find a solution to the baro deviation? im working on a 17 gt with the gt350 tb and manifold and I'm running into the same problem. the ipc error are super erratic and fuel trims become inconsistent.