Turbo Dynamics, simply a PID control system

[rao]

I wonder about me too.

 

I am just surprised with your disciplined approach you are able to toss out 40% of the data without any real explanation.

 

Mostly though, you folks are just way too serious

[Deer Killer]

I wonder about me too.

 

I am just surprised with your disciplined approach you are able to toss out 40% of the data without any real explanation.

 

Mostly though, you folks are just way too serious

Because there's something serious about daily driver with 300+whp. Right.

[mickeyd2005]

I wonder about me too.

 

I am just surprised with your disciplined approach you are able to toss out 40% of the data without any real explanation.

 

Mostly though, you folks are just way too serious

 

I didn't toss it out. I looked at the data and I can see how stable the TD integral was.

 

My approach is not as disciplined as BBB's. It's actually very simple. I just think more people need to log 4th gear between 2000 and 4000 rpm because they have problems that they don't realize they have.

 

Take a look at the OTS tune with WGDC init > 90% at 2400 rpm and WGDC max > 90% at 2400 rpm AND CL/OL delays = 0. That's going to cause problems and it has NOTHING to do with PID.

 

Forgot to add: I can toss out data if I never drive in that range.

[Deer Killer]

This didn't even show up as bad as it really was in the datalog:

http://www.legacygt.com/forums/showthread.php?t=34405

 

But yes you have to toss out data. The amount of noise is so large that except for really large errors it doesn't tell you anything. My first guess is usually good enough to get passed this point anyway.

 

Tuning = being anal. Otherwise just drive it, because it's "good enough"

[LittleBlueGT]

several people have sent me logs in 4th gear to redline and that's one of the reasons I posted the message. I was really surprised that they did it and told them not to do it anymore.

 

If you drive in 5th gear at 6000 rpm on your way to work then you should log it.

 

First you tell me not to do it, then you tell to do it..............

[LittleBlueGT]

Sometimes I wonder about you.

 

.........................

 

Come to think of it, I've never seen you post a log.

 

Why don't yo log 4th and 5th gear from 2000 to 3000 rpm?

 

There is no way rao will post a log (with the exact parameters that you specify, done the way you want, gear, rpm range etc...), no way!

 

He would then have to admit things he doesn't want to.

[Deer Killer]

With the risk of pissing of rao, here's a serious question - the MAP sensor is used for TD? How bad is it when it's maxed out? When does it max out?

[LittleBlueGT]

With the risk of pissing of rao, here's a serious question - the MAP sensor is used for TD? How bad is it when it's maxed out? When does it max out?

 

I will get back to you (when it warms up) with exact numbers, but depending on atmospheric pressure it usually will log no higher then 22.5 psi.

 

The OEM MAP will read higher then that though, but you have to log (with romraider) manifold absolute pressure direct, then subtract the atmospheric pressure.

 

I will guess it will go up to around 24 or 25 psi. Even though it will only log to 22.5, the td values still show that the ECU is seeing higher then 22.5 psi and trying to control it.

 

My guess is the OEM sensor was considered (by Subaru or whoever made it) to be inaccurate above 22.5 psi, and that is why they stopped the readings from going any higher, even though they will.

[SeeeeeYa]

There is no way rao will post a log (with the exact parameters that you specify, done the way you want, gear, rpm range etc...), no way!

 

He would then have to admit things he doesn't want to.

 

:icon_mrgr:icon_mrgr

 

LBGT FTMFWBTW

 

Disclamer:

 

rao has emense expirense an iz helpfull, an he is very serius. For one I expekt hem to cum in here and make mak u ete yure wordz.

[Deer Killer]

I will get back to you (when it warms up) with exact numbers, but depending on atmospheric pressure it usually will log no higher then 22.5 psi.

 

The OEM MAP will read higher then that though, but you have to log (with romraider) manifold absolute pressure direct, then subtract the atmospheric pressure.

 

I will guess it will go up to around 24 or 25 psi. Even though it will only log to 22.5, the td values still show that the ECU is seeing higher then 22.5 psi and trying to control it.

 

My guess is the OEM sensor was considered (by Subaru or whoever made it) to be inaccurate above 22.5 psi, and that is why they stopped the readings from going any higher, even though they will.

 

Probably just to clip bad readings. Like there's a load and a MAF limit as well.

[LittleBlueGT]

Probably just to clip bad readings. Like there's a load and a MAF limit as well.

 

Agreed.

[mickeyd2005]

The MAP sensor doesn't have a clip setting like the MAF sensor. It will go all the way until it hits the 5V maximum. The slope and offset are in the defs so you can figure out the maximum theoretical manifold pressure it can read.

 

The MRP corrected value is clipped but that has nothing to do with what the ecu is doing. You can log manifold absolute pressure direct and see where it goes. Manifold absolute pressure direct is what the ecu uses. MRP corrected is just for logging purposes.

 

However, some people have theorized that it is not accurate above 37 psi absolute. I wouldn't know.

[bugblatterbeast]

You don't need to tune boost in 5th gear above 4000 rpm. If boost is tuned correctly in 3rd gear, the boost will be stable in 4th and 5th gear from 4000+ rpm. We tend to look at boost plots with rpm on x-axis but if you plot time on x-axis, you'll see that 5th gear has plenty of time to stabilize in the 4000+ rpm range. The key is to tune boost during the pre-boost threshold range in all gears.

 

+1 a third gear pull from ~2k will give you almost all the data you need. the loads are already being limited by boost control by a bit over 3krpm. why risk taking a higher speed run. 3rd gear at redline is already sketchy for any sort of off track driving. higher gears can be simulated with less risk using a hill

[rao]

you guys are funny.

 

I don't post my logs because my car runs fine and I am not looking for advice - I set it up 3 years ago and just drive it

[SeeeeeYa]

you guys are funny.

 

I don't post my logs because my car runs fine and I am not looking for advice - I set it up 3 years ago and just drive it

 

I almost hate to admit it.... but I am beginning to appreciate that perspective .

[LittleBlueGT]

I almost hate to admit it.... but I am beginning to appreciate that perspective .

 

No you don't!

 

What are we on this site for, pure entertainment? Friendship?

 

I am here to learn about my car, get advice about modify my car, etc... IMO it is why the site exists.

 

 

Some people like to talk about the king of cars and turbos that don't fit in their garage. Then they press repeat a thousand times. Why?

 

If you want to buy a car and drive it, then fine. If you want to be a main contributor in an enthusiasts site, be an enthusiasts, which to me generally means always tinkering, never satisfied, always trying to make it better.

[Deer Killer]

No you don't!

 

What are we on this site for, pure entertainment? Friendship?

 

I am here to learn about my car, get advice about modify my car, etc... IMO it is why the site exists.

 

 

Some people like to talk about the king of cars and turbos that don't fit in their garage. Then they press repeat a thousand times. Why?

 

If you want to buy a car and drive it, then fine. If you want to be a main contributor in an enthusiasts site, be an enthusiasts, which to me generally means always tinkering, never satisfied, always trying to make it better.

+1

[Deer Killer]

Need to know:

1. Integration time variables/accumulator size

2. What conditions zero the accumulator.

 

Anyone?

[LittleBlueGT]

Need to know:

1. Integration time variables/accumulator size

2. What conditions zero the accumulator.

 

Anyone?

 

1. not sure on the time / are you asking how much the integral can accumulate to? It is adjustable with enginuity, but I think it is set at 15 to start with.

2. a certain amount of boost error will 0 it I believe, but just going from memory, take a look at romraider, there is a sticky or FAQ about how the boost control system works, it should answer all your ?s

[LittleBlueGT]

2) from romraider

 

In addition, there is a minimum positive boost error (usually very small) before integral positive correction is allowed as specified by the 'TD Integral Positive Activation (Boost Error)' table. Integral negative correction is typically only used when there is negative boost error as determined by the 'TD Integral Negative Activation (Boost Error)' table. TD Proportional is active anytime the rpm and target boost thresholds are met, regardless of boost error.

[LittleBlueGT]

Need to know:

1. Integration time variables

 

I am sure I read it somewhere (it was actually an assumption or hypothesis), but I can't find it now.

[mickeyd2005]

Set your TD integral to 1% and datalog to see how long TD integral takes to wind up.

 

I estimated it at 70-80 ms for the 05 LGT ecu. Unfortunately, I screwed up my table that time so I can't be more exact. Someone with real time tuning could check this in 5 minutes.

 

Set your boost target to less than boost threshold to clear the TD integral. So, in the "landing" areas I set boost target = 0.77 psi. This is actually important if you do fast shifting. You don't want TD integral to already be wound up as you boost up again.

[Deer Killer]

Well no that doesn't answer the question. Integration is done with respect to time. Either it keep integrating from when you meet the threshold to when it clears, or there is a integration window. This is actually important to know

 

Second, why 0.77 psi and not 0? So it seems 0.77 psi boost target is one of those things that clears accumulator. We hope. Negative values are available.

[mickeyd2005]

Well no that doesn't answer the question. Integration is done with respect to time. Either it keep integrating from when you meet the threshold to when it clears, or there is a integration window. This is actually important to know

 

Second, why 0.77 psi and not 0? So it seems 0.77 psi boost target is one of those things that clears accumulator. We hope. Negative values are available.

 

Seriously. I answered both your questions.

 

The thresholds and activations are clearly spelled out here:

 

http://www.romraider.com/forum/topic1814.html

 

The only thing that merchgod didn't give is the integrating time interval and I gave that to you.

 

I chose 0.77 psi because it is less than 0.97 psi. And 0.97 psi is in the rom. Frankly, it doesn't matter. You can pick 0, -5, -10. It doesn't matter. Once your target boost is below the disable, boost control is OPEN LOOP and the boost target is no longer used.

 

Forgot to add: The real target boost is in terms of absolute pressure. It can never be negative. The target boost as DISPLAYED in enginuity is in terms of MRP at sea level. It is only displayed like that for convenience. The ecu target boost is in terms of absolute.

[mickeyd2005]

Have you logged TD integral yet?

 

Either it keep integrating from when you meet the threshold to when it clears, or there is a integration window.

 

This is pretty cut and dry when you look at logged TD integral and compare it to the thresholds and activations in the rom.