DIY tuning
- Thread starter Sbrach
- Start date
https://datazap.me/u/sbrach/rev53?log=0&data=4-5-14-31-33&solo=31-33
Latest rev. Under boost target. Under load target. Still have the weird dip in boost request in 3rd. Shift to 4th WOT and boost request stays flat. Really bizarre.
Latest rev. Under boost target. Under load target. Still have the weird dip in boost request in 3rd. Shift to 4th WOT and boost request stays flat. Really bizarre.
It's been a while so figured it was time for an update.
Got the VRSF 7.5" race IC in. IATs either stay flat or drop a couple degrees over a multi gear pull. Magical intercooler.
Switched from NGK 95770 to N20 plugs gapped at .022. This combo has been the best I've tried so far by a large margin.
Ordered a Pure Stage 2 and got that installed.
Also, added another O2 bung so I can clock this unknown manufacturers DP correctly.
Crashed rail pressure due to starving the HPFP on the first pull with the PS2.
Vader Solutions hooked me up with a bucketless bracket and DW400.
Rail pressure is a nice flat line now with the DW400.
Added a cheap catch can
Walnut blasting my intake valves this weekend. N55 guys don't neglect this, mine are pretty bad at 100K.
Currently working on the tune, turning up boost gradually and experimenting with some MAF delete stuff so I can run a less restrictive intake with the new turbo. I'm still tapering boost a bit at high RPM because I don't want to push WGDC too much with this restrictive stock inlet.
Got the VRSF 7.5" race IC in. IATs either stay flat or drop a couple degrees over a multi gear pull. Magical intercooler.
Switched from NGK 95770 to N20 plugs gapped at .022. This combo has been the best I've tried so far by a large margin.
Ordered a Pure Stage 2 and got that installed.
Also, added another O2 bung so I can clock this unknown manufacturers DP correctly.
Crashed rail pressure due to starving the HPFP on the first pull with the PS2.
Vader Solutions hooked me up with a bucketless bracket and DW400.
Rail pressure is a nice flat line now with the DW400.
Added a cheap catch can
Walnut blasting my intake valves this weekend. N55 guys don't neglect this, mine are pretty bad at 100K.
Currently working on the tune, turning up boost gradually and experimenting with some MAF delete stuff so I can run a less restrictive intake with the new turbo. I'm still tapering boost a bit at high RPM because I don't want to push WGDC too much with this restrictive stock inlet.
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wow you got everything installed quick! good to see her running well. Surprised your rail pressure was tanking at 16psi with the stock LPFP. I wonder if it was on it's way out.
Looking forward to the work on MAF delete so a short intake can be run.
Looking forward to the work on MAF delete so a short intake can be run.
So the general consensus of the table to change that has somewhat the same effect as the old "WGDC Base" is "Compressor characteristic with required compressor / turbine power"? I understand that manipulating this table to get a desired effect after say catless downpipe does work but it's got me thinking if there is a more correct table to change. Going catless downpipe doesn't actually change the turbine energy required to drive the compressor. It might be worth trying some of the many other boost control related tables that are more related to the turbine and exhaust gas. Here are some examples not yet in the public XDFs but there are plenty more:
KL_AUSYKAT_AKZU - Cat (everything downstream of the turbo actually) pressure drop over flow with exhaust flap off
KL_AUSYKAT_AKAUF - Cat (everything downstream of the turbo actually) pressure drop over flow with exhaust flap on
KF_AUSY_TURB - Turbine flow characteristic
KF_ATM_ATLETA - ATL efficiency
KL_ETA_TURB - Turbine efficiency
KF_FGAS_WG - Gas force on the wastegate
KLEWGFGAS - Characteristic: wastegate force vs duty cycle
The DME manufacturer certainly have set things up to be very modular so they can switch turbo for example and just punch in the new numbers that apply to it and everything else should get pretty close to what it should be.
Changing the correct tables for a given hardware change should keep things like calculated exhaust gas temp, calculated exhaust back pressure, VE etc more correct.
I'm most interested to see if changing the pressure drop over cat tables after going catless and see if they have an effect on base WGDC that's calculated by the DME.
It'd also be great to get things like the proper way to go MAFless out in the open to allow DIY tuners to have further resources.
KL_AUSYKAT_AKZU - Cat (everything downstream of the turbo actually) pressure drop over flow with exhaust flap off
KL_AUSYKAT_AKAUF - Cat (everything downstream of the turbo actually) pressure drop over flow with exhaust flap on
KF_AUSY_TURB - Turbine flow characteristic
KF_ATM_ATLETA - ATL efficiency
KL_ETA_TURB - Turbine efficiency
KF_FGAS_WG - Gas force on the wastegate
KLEWGFGAS - Characteristic: wastegate force vs duty cycle
The DME manufacturer certainly have set things up to be very modular so they can switch turbo for example and just punch in the new numbers that apply to it and everything else should get pretty close to what it should be.
Changing the correct tables for a given hardware change should keep things like calculated exhaust gas temp, calculated exhaust back pressure, VE etc more correct.
I'm most interested to see if changing the pressure drop over cat tables after going catless and see if they have an effect on base WGDC that's calculated by the DME.
It'd also be great to get things like the proper way to go MAFless out in the open to allow DIY tuners to have further resources.
Sick progress and updates. Just did my intake valves too at 105,000 miles and it looked about the same as yours. In doing the intake valves I seemed to have bricked my FRM. Did you run into any problems when reconnecting everything?
I’ve had my intake manifold off a couple times and haven’t had any problems. I’m doing the actual valve cleaning tomorrow. Just got the tools. I don’t think there is anything plugged into the DME that would cause an FRM problem. They are known to go bad. What are the symptoms?
Typical symptoms of bricked FRM. No interior lights, windows not working, light control not working etc. Maybe it was due to battery when I was closing opening/closing intake valves via starter.
Used to do tuning on my N55 in command WGDC and I originally thought commanded would be easier and better but I've since changed my mind. Switch back to PID and work on it. Post up some logs and I'll see if I can point you in the right direction, I now have an N54 but still do my own tuning on it.
This is my latest log with commanded WG. Why did you change your mind regarding full PID vs commanded?
https://datazap.me/u/sbrach/rev49c-0?log=1&data=3-4-14
https://datazap.me/u/sbrach/rev49c-0?log=1&data=3-4-14
Exactly what I was going to ask. I keep hearing PID is better, but no one can explain to me why. Would be nice to understand a little better the advantages. Also, @bahn, I think the N54 is a little easier to tune than N54. What do you think now that you have tuned both?
Like @Sbrach has mentioned, we have had good results with commanded wgdc. Latest dyno and logs below.
PS2 E30 - Got 8 pulls in. Picture of results and links to logs below. Will update the dyno runs with prettier graph when I get the chance. The run with 526hp is actually due to a spike at shift (will clean this up when I get a chance). Just wanted to show my results for now. She was spitting some nice flames as well :thumsup:
Dyno Graph Picture
Fireball 1
Fireball 2
Logs:
PS2 E30 – 4/24/18 dyno logs
Run 1 and 2 (only pull in 4th just to try): https://datazap.me/u/houtan/sbrach-v466?log=0&data=4-18-22&solo=22&mark=22
Run 3 and 4: https://datazap.me/u/houtan/sbrach-v466-dyno-load-run-3-and-4?log=0&data=4-18
Run 5: https://datazap.me/u/houtan/sbrach-v466-v27-dyno-load-run-5?log=0&data=4-18
Run 6, 7, and 8: https://datazap.me/u/houtan/sbrach-v466-v28-dyno-load-run-6-7-8?log=0&data=4-18
Command WGDC can work really well if you spend a lot of time working on it however IMO it will never match the variability of a PID system to maintain boost and safety thresholds. Commanded WGDC removes the DME's ability to decrease WGDC to correct deviation from boost target, without that ability the DME falls back on the throttle blade to reduce air flow as a safety mechanism. To get around throttle closures it's common to see the load req set way above what the WGDC table will be able to reach. You can see this in your tune, granted not as badly as I've seen some. In the same breathe Commanded WGDC removes the DME's ability to increase WGDC to get on boost target quickly, hold it accurately and correct for atmospheric variability. I would recommend working your way back up with the PID system. Feel free to send me your logs if you run into a road block.
Nice results @houtan, there's no doubt you can do well with commanded WGDC. As I said in a post a long time ago on another forum, there's plenty of cars out there running manual boost controllers to great effect. A well tuned PID system is exceptional at quickly, accurately and consistently achieving a target even when conditions may be variable. The commanded WGDC method may seem easier to understand at first but once you get the hang of PID you'll quickly realize you can achieve the same or better control much faster. As for N54 vs N55, having tuned both now I feel they are similar. The confusion is the WGDC Base table vs the compressor characteristic table. There is a difference in how the base WGDC % is calculated behind the scenes but for the sake of tuning I just treated the compressor characteristic table as a WGDC base table.
Commanded WG is a bit of a misnomer. It just replaces the turbine power calculation with the "commanded wg" table which is really just a different way to get a base WG value than calculationg the turbine power required to turn the compressor. I agree with Brad in that unless you start altering the exhaust gas flow and pressure models (neural network) then none of the stock wg control really works as intended.
From my discussions with John that's not entirely correct. The only portion of the PID system that remains active in commanded wgdc mode is the integral, both proportional and derivative are disabled.
I am honestly an amateur compared to you guys and always in learning mode. If PID is better and someone starts sharing how they are doing that approach, I will try it. Right now I am solid on commanded wgdc, and using it under the assumption that it's a safe approach.
In addition, I do believe there are some limiters for DCT cars that haven't been discovered or not been released to the general public which hopefully sbrach will uncover. In higher boost maps, with perfect logs, I get a misfire code around 5900 rpm from time to time. It seems something is being tripped because it's always around the same RPM when it does occur.
In addition, I do believe there are some limiters for DCT cars that haven't been discovered or not been released to the general public which hopefully sbrach will uncover. In higher boost maps, with perfect logs, I get a misfire code around 5900 rpm from time to time. It seems something is being tripped because it's always around the same RPM when it does occur.
Still using the stock flywheel? If I recall the M4 flywheel is reported to resolve high boost misfires by Pure Turbos.
Yup, stock flywheel, stock clutchpack. From what I have seen on my friends car, the M4 flywheel definitely lets you run more boost. But even in his car, when I go to crank up the boost to 23 or 24 psi, the same thing starts happening again where the log looks good but cylinder misfire occurs. Kind of like you are hitting some sort of torque limiter. I don't know if adding the lighter flywheel reduces the values that are causing the limiter to trip or if it's something else.
I am hoping the M-factory smfw has good reviews so I will wait for that. I'm in no rush because the daily map with 460whp and the DCT absolutely rips. The higher boost will be nice for a half mile event though. But I really want to know what is causing the misfire when the log looks good, in a DCT car.