Boost spike/creep problem again.
10-22-2008, 10:21 PM
#21
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You can also just use P, PI, PD, etc, depending on the situation/application.
10-23-2008, 02:46 AM
#23
Sound like you a power and control tech/instrument mech! ha..
10-23-2008, 05:17 AM
#24
Sorry I didn't mean to be confusing. Just giving you a starting point for the parameters to plug into the boost controller.
I learned it because I was running open loop but wanted to run closed loop so read some engineering articles on PID closed loop feedback algorithms. Everything is on the net.
Here is mine for the Haltech using a 30 Hz boost solenoid (I have an internal wastegate setup, but for boost control, I think this all still applies similarly):
Start duty cycle: 35%
Target boost turn on point: 3 psi (that is the feedback becomes active 3 psi before target boost)
Proportional: 8
Integral: 4
Derivative: 0
If you search on Google, you'll find the setup for the Hydra EMS. The #s are all very different. I would highly recommend starting small. You will find that boost response suffers and you don't reach target boost. BUT you are safe! Then gradually increment #s and track your boost. Just need to dial it in...
EDIT: And many thanks go to Hal at Injected Performance and Sharif at Forged Performance for providing insight along the way. I bet I've asked Hal more questions about the Haltech than any other person on the planet.
I learned it because I was running open loop but wanted to run closed loop so read some engineering articles on PID closed loop feedback algorithms. Everything is on the net.
Here is mine for the Haltech using a 30 Hz boost solenoid (I have an internal wastegate setup, but for boost control, I think this all still applies similarly):
Start duty cycle: 35%
Target boost turn on point: 3 psi (that is the feedback becomes active 3 psi before target boost)
Proportional: 8
Integral: 4
Derivative: 0
If you search on Google, you'll find the setup for the Hydra EMS. The #s are all very different. I would highly recommend starting small. You will find that boost response suffers and you don't reach target boost. BUT you are safe! Then gradually increment #s and track your boost. Just need to dial it in...
EDIT: And many thanks go to Hal at Injected Performance and Sharif at Forged Performance for providing insight along the way. I bet I've asked Hal more questions about the Haltech than any other person on the planet.
Last edited by rcdash; 10-23-2008 at 05:37 AM.
10-23-2008, 05:48 AM
#26
http://en.wikipedia.org/wiki/PID_controller is a great place to start. It's not really complex at all. The table halfway through that tells you what happens when you increase parameters is all you really need to do some troubleshooting (e.g. it tells you that if you increase Proportion and Integral, overshoot INCREASES, etc.).
(I think their first graph is labelled wrong though, it shows the overshoot increase with a lower Kp - I think they got that backwards. The text, tables, and remaining graphs look correct to me though.)
(I think their first graph is labelled wrong though, it shows the overshoot increase with a lower Kp - I think they got that backwards. The text, tables, and remaining graphs look correct to me though.)
Last edited by rcdash; 10-23-2008 at 05:52 AM.
10-23-2008, 08:22 AM
#28
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I've tried setting the b/c @ 8.5psi and it still creeps. I'm beginning to think it has to do w/ the weather at least some b/c it did it worse when it was below 55deg. I got on it hard yester day and it only did it a little. I even turned the gain down on the BC. There has to be something I can do to keep it from doing it in cold weather, right?
10-23-2008, 09:47 AM
#30
I have dual tial 44mm's. A buddy of mine told me they maybe getting gunked up b/c of soot and I should take them apart and clean them. Any thoughts on that?
I've tried setting the b/c @ 8.5psi and it still creeps. I'm beginning to think it has to do w/ the weather at least some b/c it did it worse when it was below 55deg. I got on it hard yester day and it only did it a little. I even turned the gain down on the BC. There has to be something I can do to keep it from doing it in cold weather, right?
I've tried setting the b/c @ 8.5psi and it still creeps. I'm beginning to think it has to do w/ the weather at least some b/c it did it worse when it was below 55deg. I got on it hard yester day and it only did it a little. I even turned the gain down on the BC. There has to be something I can do to keep it from doing it in cold weather, right?
and my wastegate had a thin layer of black soot on it as it should and wiped off easy. If theres enough on there to jam it up then you have a bigger problem than you know of.
10-24-2008, 02:20 PM
#34
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It has to do with having very low exhaust backpressure and the air not making the turn into the wastegate due to a small pressure differential between the turbine and wg inlet.
10-26-2008, 08:29 PM
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Not sure if it's spiking b/c when I take off I keep my eyes on the road, but it's going up to 9.9psi w/ the boost controller off. My springs are 8.5psi and I have the EVC 6 bc. It did it one time before after I disconnected the batt. I had to reset everything on the BC. This time it's just started doing it on it's own and I have no idea what to check.
10-27-2008, 10:05 AM
#38
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If you are not wanting to go much over 8.5 you probably want to get a 5 lb spring. I had a tial wg with 8.5spring thinking it wouldn't go over 8.5 but it would spike to 11 when you just jump on the throttle. I downgraded to a 5 lb spring and I have to hammer it to get it up to 8. With ebc it just allows you to run higher psi by just regulating the vacuum signal to the wg. An 8.5 spring probably starts opening the gate around 5 psi. All this is relevant if you have no vacuum leaks in the wg line you checked.
10-27-2008, 04:51 PM
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Okay, reset the the BC today, it is still doing it. It is definitely creeping, not spiking, & weather related. It was up in the 70's outside today and it held boost fine. It dropped to the low 50's after the sun went down and it started creeping. Hit 8.5 and kept going up to 9.0 when I let off just before RL. I have fuel line run to the wg's my friend said, so they shouldn't be crushing. I' gonna try to replace the springs if nobody has any other ideas.