how-to: ECU-based direct boost control
#1036
Anyone know the answer to this? Also if boost error is showing -3 do i need to add wgdc or remove?
#1037
im not sure exactly on the omni settings, but the omni 4bar boost error formula in the xml is what you use in evoscan.
as for a -3 boost error, it means that at that point of logging, it read that the boost was 3psi lower than target. you would need to add wgdc.
cheers
as for a -3 boost error, it means that at that point of logging, it read that the boost was 3psi lower than target. you would need to add wgdc.
cheers
The following users liked this post:
japspec (Oct 27, 2019)
#1038
I actually stopped using PSI based boost control because its irrelevant to tuning on the stock ECU IMO. We tune for a desired LOAD curve, a path in which we want the ECU to follow every single time. With the same boost under different air temps and other climate conditions will yield different load curves. Using load based boost control ensures you are riding on the same curve at all times.
-Jamie
-Jamie
The only fault I find with load based boost, is for different temps/situations, it takes different amounts of boost to get the desired load. Not that thats an actual issue but a customer will think their boost is not stable, if sometimes they see it hit 22 and some times 25.
#1039
(Not trying to sound like a smartass BTW, just want to start a little discussion on the subject )
#1040
I have started to think like this also. Load based boost may be better the PSI based boost.
The only fault I find with load based boost, is for different temps/situations, it takes different amounts of boost to get the desired load. Not that thats an actual issue but a customer will think their boost is not stable, if sometimes they see it hit 22 and some times 25.
The only fault I find with load based boost, is for different temps/situations, it takes different amounts of boost to get the desired load. Not that thats an actual issue but a customer will think their boost is not stable, if sometimes they see it hit 22 and some times 25.
It makes the WHP more stable all year long.
Last edited by domyz; Oct 11, 2012 at 10:16 AM.
#1041
This might be a noob question, well actually it is a noob question. First of, yes I have searched for this but cant find it. I have tuned the car currently using my mbc , now trying to go with ecu-boost using grimspeed.
I have the tephra v7 94170715 rom and I see all the tables besides the Baseline Boost curve table. I know that table is for the WGDC, the only one that looks right is Main map wastegate duty. Do I use that one?
under global boost settings I see:
WGDC correction interval (high gear range)
WGDC correction interval (low gear range)
Under Boost Control settings I see:
Main map wastegaate duty
boost desired engine 'load'
boost desired engine 'psi'
boost adder (load)
boost adder (psi)
Im assuming that its the Main map wategate duty but this is what it is right now:
0 1 2 3 4 5 6
500
1000
1500
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
6000
6500
7000
I have the tephra v7 94170715 rom and I see all the tables besides the Baseline Boost curve table. I know that table is for the WGDC, the only one that looks right is Main map wastegate duty. Do I use that one?
under global boost settings I see:
WGDC correction interval (high gear range)
WGDC correction interval (low gear range)
Under Boost Control settings I see:
Main map wastegaate duty
boost desired engine 'load'
boost desired engine 'psi'
boost adder (load)
boost adder (psi)
Im assuming that its the Main map wategate duty but this is what it is right now:
0 1 2 3 4 5 6
500
1000
1500
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
6000
6500
7000
#1042
Yes, you first adjust main wastegate duty. Make sure the boost error correction (BEC) table is zero'ed out. When you have the boost curve you want you can configure either load-based or psi-based control and correction.
#1043
thanks for confirming.
I know this has already been answered but currently all the values are 0. what should i start off at? Of course as i go on, ill increase it. Looking for a safe place to start it.
I know this has already been answered but currently all the values are 0. what should i start off at? Of course as i go on, ill increase it. Looking for a safe place to start it.
#1044
Here is mine: 2.0L, 2005 VIII turbo, Grimmspeed 3 port, 23.5 psi taper to 21:
3rd gear
500 100
1000 100
1500 100
2000 100
2250 100
2500 100
2750 90
3000 79
3500 63.5
4000 63.5
4500 64.5
5000 66.5
5500 67
6000 69
6500 70.5
7000 71.5
For tuning it's useful to know your car "rule of thumb", something that goes like this: 1%WGDC changes in my car yields about 0.6 psi.
Have fun
Last edited by domyz; Nov 14, 2012 at 02:30 PM.
#1045
Do you have that for each gear?
In my table for Main map wategate duty it has x-axis is gear, y-axis is rpm
GEAR
0 1 2 3 4 5 6
500
1000
1500
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
6000
6500
7000
In my table for Main map wategate duty it has x-axis is gear, y-axis is rpm
GEAR
0 1 2 3 4 5 6
500
1000
1500
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
6000
6500
7000
#1046
Example from VGergo, flat boost curve (obviously not the same setup):
1st-2nd gear will need higher WGDC numbers at low RPM, 4-5th gear will need lower WGDC at low RPM. Keep in mind to not raise the 1st and 2nd gear WGDC too much because when uphill you'll overshoot. (not too much but still safety first )
There is some maps in these forums if you search a bit. My car doesn't like a flat boost curve, it knocks and I need to pull too much timing to counter that. The best for me on 91 octane was 23.5 taper to 21 boost curve.
Last edited by domyz; Nov 14, 2012 at 05:54 PM.
#1048
Read post #3 from mrfred in this thread. Desired boost + boost adder tables are compared to actual(map sensor) boost and the boost error correction do his job by changing the WGDC.
Could also help:
https://www.evolutionm.net/forums/ec...implified.html
Could also help:
https://www.evolutionm.net/forums/ec...implified.html
#1049
BDEL/psi + Boost Adder = your targeted load or psi
WGDC is how you reach your target load/psi for a given rpm. The reason you tune boost with the correction zero'd is to get your WGDC curve to hit your target. Then you apply the corrections to account for weather variables the may cause you to undershoot/overshoot your target.
WGDC is how you reach your target load/psi for a given rpm. The reason you tune boost with the correction zero'd is to get your WGDC curve to hit your target. Then you apply the corrections to account for weather variables the may cause you to undershoot/overshoot your target.
#1050
I have started to think like this also. Load based boost may be better the PSI based boost.
The only fault I find with load based boost, is for different temps/situations, it takes different amounts of boost to get the desired load. Not that thats an actual issue but a customer will think their boost is not stable, if sometimes they see it hit 22 and some times 25.
The only fault I find with load based boost, is for different temps/situations, it takes different amounts of boost to get the desired load. Not that thats an actual issue but a customer will think their boost is not stable, if sometimes they see it hit 22 and some times 25.
To me it may not be an issue to someone who simply dd's or does the occaisional un-sanctioned race, but to say a track day, tt, or road racer it may be an issue. Especially late in a session or race when everything is hot already and maybe the turbo starts getting outside of its efficiency range trying to hit a desired load.
Not saying it would but..... what if?