Some fun testing - motec sidewinder

[ClutchMaster]

Doing it this way you’ll be able to turn down PID gain, I log the boost error, and make changes to the duty table a couple of cells ahead of the impending overshoot.

 

[boostfever]

Closed loop boost control tells you immediately on the first run where your base line duty cycle should be. Its all in the data log, if you have it set at 60%, and after 2-3 seconds closed loop control settles it at 64% duty cycle, you just set the aim to 64%. It seems brent has his boost well under control 1.5 seconds into a run, and I am not pretending to be a total expert on all of this, just sharing what worked for me as I worked thru many of the issues brent is experiencing here.


Also I miss spoke a little about what margin does, boost control activate is its own setting.
Margin puts the boost controller at 100% duty cycle until the actual boost is within a certain value of the aim boost. For example if margin is set at 30kpa, it will hold controller duty cycle at 100% until boost is within 30kpa of the target boost. If margin is set to close it can cause overboost because pid does its math working down from 100%, and it cant get there in time

 

[Brent68]

Have you watched to motec webinar about pid.
These are the three parameters the motec uses for boost control.
Another thing to look at that had a major effect on initial overboost is the margin setting, margin determins when the boost controller becomes active. If margin is set to close to aim it will cause a boost overshoot because the motec is late to the game and boost is already ramping up quicker than it can calculate where it needs to be.
Pid requires very small adjustments to the values. Fun stuff dialing these in

Just watched the first one. I’m going to increase the derivative gain some and test. Thanks for the suggestion.

 

[ClutchMaster]

I see, my ecu I have to set the WGDC table yourself, it’s not automatic. You have fancy new ecu’s!
Totally concur that turning on the boost control to soon or to late can cause overshooting. Too soon and you’ll have intergral wind up of the PID equation. Too late and it won’t have enough time to react.

Just trying to help, I love this $hit!

 

[ClutchMaster]

Here’s a boost curve for ya, ramps slow but it’s a big turbo.
Very conservative timing down low helps control wheel spin and knock, then the timing is brought in to bring the power up as traction increases.

 

[Brent68]

View attachment 145137
Here’s a boost curve for ya, ramps slow but it’s a big turbo.
Very conservative timing down low helps control wheel spin and knock, then the timing is brought in to bring the power up as traction increases.

Wow, very cool!

 

[ClutchMaster]

Thought you might like that. Turbo is struggling to hold 40 psi up top.

 

[Brent68]

Thought you might like that. Turbo is struggling to hold 40 psi up top.

Getting the engine to hold together at 40 psi is an accomplishment for sure.

 

[boostfever]

Its all fun. I kind of self learned a lot of this, I really only trail ride, but I have 3 riding buddies with similar set ups to mine, and few sidewinders friends as well, so I really enjoy trying to get everything fine tuned as much as possible to have the edge on them.
I was getting frustrated with the clutching, but as I got the motec dialed in more on the boost controll side of things, the clutching became easier. I was finally able to figure out what I was missing in the clutching.

Now I have martin building a motec 900ace for me, Starting all over with the p-drive clutch should be interesting.

 

[ktmhk53]

'Looking forward to updates Brent

 

[Brent68]

'Looking forward to updates Brent

No updates this week on motec sidewinder. We raced the 1200 doo and the flashed sidewinder at a local event. It was fun to spend the day at the track, even better that both sleds placed first in their class. The flashed sled was in a stock turbo pump gas class. We used the max spool 17 tune, reduced the fuel pressure to get the AFR to 12:1, it picked up 200 rpm. Works nice for anyone that has the adjustable fuel pressure regulator.....careful because the engine did register a very small knock at the end of a 660 pull.

Have a great week and nice to see the snow flying!

 

[sledding rocks]

No updates this week on motec sidewinder. We raced the 1200 doo and the flashed sidewinder at a local event. It was fun to spend the day at the track, even better that both sleds placed first in their class. The flashed sled was in a stock turbo pump gas class. We used the max spool 17 tune, reduced the fuel pressure to get the AFR to 12:1, it picked up 200 rpm. Works nice for anyone that has the adjustable fuel pressure regulator.....careful because the engine did register a very small knock at the end of a 660 pull.

Have a great week and nice to see the snow flying!

this is very interesting , im also running max spool 17 with a header and a 3 inch exhaust , and a fuel pump and fuel reg , I had to turn up the fuel reg to 48 psi to run in the 12.3-12.4 range , I haven't seen knock yet with mobile 93 with Lucas , I still want to get it in the high 11 , not sure how much more can I turn up the fuel reg ?

 

[ClutchMaster]

If your not seeing knock just leave alone. You’ll always make more power above 12:1 afr. You can keep turning it up as long as your idle/cruising afr’s dont dip to low, then mileage will start to suffer. What is the stock fuel pressure?

 

[sledding rocks]

If your not seeing knock just leave alone. You’ll always make more power above 12:1 afr. You can keep turning it up as long as your idle/cruising afr’s dont dip to low, then mileage will start to suffer. What is the stock fuel pressure?

stock fuel pressure was 43 psi , but I was seeing 13.1 a/f , with knock at roughly 1500 ft , then I added the fuel reg and turned it up to 48 psi to bring done the a/f to 12.3-12.4. so far no knock , idle good /cruising also good , , yes I have seen the fuel milage decrease , the header and 3inch exhaust combo needs more fuel for sure , power is strong , very trail friendly also , the nice thing about the fuel reg its simply to adjust , thanks for your response clutch master , the fuel reg is new to me , just not sure what the limits r by turning it up ,

 

[ClutchMaster]

Sounds like the header is working well. It’s too bad we can’t get our hands on some programming software for our sleds. I wish I had timing control, I heard the pcv ignition module doesn’t work that well. F-it I’ll probab get a stand-alone next year anyway.