HOW TO - Control boost using ECUFLash and the stock boost solenoid
Evolved Member
Joined: May 2006
Posts: 2,399
Likes: 6
From: UK
Needs custom modifications to your ROM. This is a complex area/advanced topic, there are threads about it. Most people get away with looking at their ignition timing to see what cell they're in.
With standard induction the graph I posted should be a good guide for most.
With standard induction the graph I posted should be a good guide for most.
Today, I lowered the values in the boost correction table from the stock values, and the boost stays more stable (makes sense right?) compared to before. I also tried to match up the values in the boost desired engine load tables to match what I was actually getting.
If your actual load matches your desired, no boost correction and therefore the boost pressure should stay more stable.
Evolved Member
Joined: May 2006
Posts: 2,399
Likes: 6
From: UK
Sounds like you've got it nice. Now all you want the closed loop control boost control for is to make sure the held boost is the same between gears and different driving conditions/temperatures even though the peaks will vary. Smaller correction values are nice to make it smooth and avoid oscillations as long as it quickly comes to target.
Evolving Member
Joined: Jun 2004
Posts: 208
Likes: 0
When u mentioned that u remove the taper by using the max wastegate duty, are you referring to inputting the values to 100 max or reducing this 100 figures?
Please advise...
Please advise...
After a few more adjustment on Ecuflash I was finally able to remove the mbc effect (less boost on low gears, more boost on higher gears), this was done by using the boost error correction. I strongly suggest you guys messing with these intead of just changing everything to zero. Have you guys ever wonder why the factory set, the first four to 8.0 and the last four to -13.0? By messing with the boost error correction I notice that the first four adds more loads (more boost) on lower gears, and the last four put less loads (less boost) on higher gears:
-20.0 = 8.0
-17.5 = 8.0
-15.0 = 8.0
-12.5 = 8.0
-10.0 = 6.5
-7.5 = 4.5
-5.0 = 3.5
-2.5 = 2.0
0.0 = 0.0
2.5 = -1.5
5.0 = -3.5
7.5 = -5.0
10.0 = -6.5
12.5 = -13.0
15.0 = -13.0
17.5 = -13.0
19.8 = -13.0
I also notice that when the boost control load offset is set at 80, the ecu is actually removing loads on 3rd gear, by changing this to 100 the ecu did not start removing load till 5th gear. I set my boost to 22 psi on 3rd gear, remove the taper by using the max wastegate duty, then lower the boost on high gears by changing the last four to -20.0:
12.5 = -20.0
15.0 = -20.0
17.5 = -20.0
19.8 = -20.0
I also notice that having both restrictor pill actually helped removing the spike, when I remove the one close to the solenoid all I get is spike on low rpm.
Just remember all evos are different, let me know if this works for you.
-20.0 = 8.0
-17.5 = 8.0
-15.0 = 8.0
-12.5 = 8.0
-10.0 = 6.5
-7.5 = 4.5
-5.0 = 3.5
-2.5 = 2.0
0.0 = 0.0
2.5 = -1.5
5.0 = -3.5
7.5 = -5.0
10.0 = -6.5
12.5 = -13.0
15.0 = -13.0
17.5 = -13.0
19.8 = -13.0
I also notice that when the boost control load offset is set at 80, the ecu is actually removing loads on 3rd gear, by changing this to 100 the ecu did not start removing load till 5th gear. I set my boost to 22 psi on 3rd gear, remove the taper by using the max wastegate duty, then lower the boost on high gears by changing the last four to -20.0:
12.5 = -20.0
15.0 = -20.0
17.5 = -20.0
19.8 = -20.0
I also notice that having both restrictor pill actually helped removing the spike, when I remove the one close to the solenoid all I get is spike on low rpm.
Just remember all evos are different, let me know if this works for you.
Does anyone know if the ECU uses feedback from the stock MAP sensor for error correction or load calculation at all? The reason why I'm asking is because I currently have my stock MAP sensor disconnected and have a GM 3-bar MAP sensor wired in.
I'm trying to tweak my P2 boost control and increasing the wastegate duty cycle has made no real difference. I only had time to increase the wg duty cycle by 3% across the board though. I'll try increasing it more when I have time this weekend.
I'm trying to tweak my P2 boost control and increasing the wastegate duty cycle has made no real difference. I only had time to increase the wg duty cycle by 3% across the board though. I'll try increasing it more when I have time this weekend.
I dont think the ECU uses a map sensor to determine load. The stock map sensor only reads vacuum to about 3 psi. I think the ECU calculates load based on injector duty cycle / maf frequency / rpm or something like that.
I now know why puttin all 159s in the desired load table make taper go away..
Say you hittin 240 load @ 3500 and 200 load @ 7000.
If all you tables say 159 + the offset, 80, that mean from 3500-7000, you target load is 240.
Now at 3500 you hit that, so the WG duty doesnt change but at 7000 your @ 200, which is 17% under target
Turbo error corr. @ -17% is +8 WG duty.
Say you hittin 240 load @ 3500 and 200 load @ 7000.
If all you tables say 159 + the offset, 80, that mean from 3500-7000, you target load is 240.
Now at 3500 you hit that, so the WG duty doesnt change but at 7000 your @ 200, which is 17% under target
Turbo error corr. @ -17% is +8 WG duty.
Instead of maxing out the desired boost tables, why not increase the offset? It would, in theory, allow you to decrease all cells in the desired boost table and achieve stock response while allowing control of the boost curve with the desired boost table along with the Max WGD tables.
This would also affect all 3 desired boost and WGD tables, which I would consider desirable since we still aren't sure if the tables are gear based.
Has this been tested at all? I do not have boost logging abilities and am a little hesitant to play with these setting too much.
Evo_Kid, as you know I'm trying to wrap my head abound this theory. Reading the above popped a thought into my head ...
Instead of maxing out the desired boost tables, why not increase the offset? It would, in theory, allow you to decrease all cells in the desired boost table and achieve stock response while allowing control of the boost curve with the desired boost table along with the Max WGD tables.
This would also affect all 3 desired boost and WGD tables, which I would consider desirable since we still aren't sure if the tables are gear based.
Has this been tested at all? I do not have boost logging abilities and am a little hesitant to play with these setting too much.
Instead of maxing out the desired boost tables, why not increase the offset? It would, in theory, allow you to decrease all cells in the desired boost table and achieve stock response while allowing control of the boost curve with the desired boost table along with the Max WGD tables.
This would also affect all 3 desired boost and WGD tables, which I would consider desirable since we still aren't sure if the tables are gear based.
Has this been tested at all? I do not have boost logging abilities and am a little hesitant to play with these setting too much.
I want to run 25psi 24/7 (alchy injection). I dont really care if it initially spikes higher the settles to 25psi as I am not seeing any knock at all. Is anyone having luck holding higher boost with the BCS?
I'm currently using an EBC but it gets a little shaky up top. I see boost drift from 23-25 psi through most of fourth gear. I've been told that the EBC isn't the best at high boost and I'm looking for a replacement. Is the ECU capable of holding higher boost levels (with the new wastegate pill)?
I'm currently using an EBC but it gets a little shaky up top. I see boost drift from 23-25 psi through most of fourth gear. I've been told that the EBC isn't the best at high boost and I'm looking for a replacement. Is the ECU capable of holding higher boost levels (with the new wastegate pill)?
EvoM Guru
iTrader: (50)
Joined: Mar 2006
Posts: 9,675
Likes: 132
From: Tri-Cities, WA // Portland, OR
I want to run 25psi 24/7 (alchy injection). I dont really care if it initially spikes higher the settles to 25psi as I am not seeing any knock at all. Is anyone having luck holding higher boost with the BCS?
I'm currently using an EBC but it gets a little shaky up top. I see boost drift from 23-25 psi through most of fourth gear. I've been told that the EBC isn't the best at high boost and I'm looking for a replacement. Is the ECU capable of holding higher boost levels (with the new wastegate pill)?
I'm currently using an EBC but it gets a little shaky up top. I see boost drift from 23-25 psi through most of fourth gear. I've been told that the EBC isn't the best at high boost and I'm looking for a replacement. Is the ECU capable of holding higher boost levels (with the new wastegate pill)?
