HOWTO: Boost Control (BA/BF)

[Lucky]

hey guys just reviewing the above can anyone tell me what Auf0286 does the above is completely different than in my car just wondering why 

1850    600
1900    600
1950    500
2000    400
2250    300
3000    225
3500    160

[Roland@pcmtec]

It isn't that different. I'm guessing you have an FG with the smaller turbo? Just means you have less integral gain on the PID controller. 

You can read about the integral action on a PID controller here

https://en.wikipedia.org/wiki/PID_controller

[Lucky]

no the readings is actually turbo territory stock read from my car but i have now changed it to a front mount intercooler so im guessing as stock intercooler pipe run is a lot shorter hence not as large adjustments, so i should probably change these to a BF turbo settings instead 

[Roland@pcmtec]

That would explain it!

Best way is to log desired boost vs actual boost (or boost error). Then change the settings and see how it is. You could use megalog viewer to make sure you are comparing apples with apples with the datalog (eg filter on data that is the same load/rpm).

Without a datalog/dyno you probably won't notice it, unless you are seeing wildly swinging boost pressure you can probably just leave it.

[JMSMotorsport]

Am I on the right track with my thinking.
 

Set PID gains to Zero - alter the Wastgate DC table until I get desired boost then turn the PID control on and set my Desired Table?

As I’m  having an issue trying to dial the DC table in aiming for 18-20psi with a 3584R Turbo.

One moment if I commanded .88  at 3500 it would shoot over the target so reduced to .75 and was well under so crept it up trying to meet target ended up past the initial .88 and up to .93 where it over shot again. I’m leaning towards a sticky solenoid? Or am I doing something wrong. 

[Roland@pcmtec]

Is this a stock turbo? They will never control boost properly at those duty cycles. You will have 18psi in the mid dropping to 12psi at redline. 

The flapper needs porting if you want to reliably run a flat boost curve

[JMSMotorsport]

Modified turbo and flapper. 

[Roland@pcmtec]

5 hours ago, JMSMotorsport said:

Modified turbo and flapper. 

What spring?

[JMSMotorsport]

4 minutes ago, Roland@pcmtec said:

What spring?

Makes 10psi on gate.
With duty set to 0

 

 

[Roland@pcmtec]

3 minutes ago, JMSMotorsport said:

Makes 10psi on gate.
With duty set to 0

It is really too small for your target, hence the high duty cycles you are requiring to get there. a 12-14psi spring would be more controllable, or using a 3/4 port setup and closed loop boost control would let you get a very wide boost range.

[JMSMotorsport]

So moving to a 3/4 Port MAC Valve like what’s Independent Motorsports sells? Customer was looking at this so will get him to pull the trigger on one. 

[Roland@pcmtec]

5 hours ago, JMSMotorsport said:

So moving to a 3/4 Port MAC Valve like what’s Independent Motorsports sells? Customer was looking at this so will get him to pull the trigger on one. 

Be aware of how much tuning this will require. Even a 5c change in ambient temperature can cause a large change in boost pressure, and even 0.1% change in duty cycle can make a measurable change so you must have closed loop boost control for a 4 port setup to work correctly. This assumes you are using an external gate with the ability to be plumbed up like a 4 port.

If you haven't done this before I would set aside a day to get your head around how to tune a 4 port setup. You may need to de-sensitise the valve by using a different hz pulse width.

[JMSMotorsport]

Ok so would need to go to an external gate and a 4 port. Simply swapping from the factory solenoid to a 3 port MAC valve won’t give me any benefits? I’m guessing not as they are basically the same thing.

[Roland@pcmtec]

Have a look at how they are plumbed up. The valve doesn't do anything special it is the plumbing configuration that makes it clever

[JMSMotorsport]

9 minutes ago, Roland@pcmtec said:

Have a look at how they are plumbed up. The valve doesn't do anything special it is the plumbing configuration that makes it clever

Yep understand how they work, but on a single port internal gate there isn’t another option to a 3 port? 

Can I add some pre-load to the wastegate to increase my base boost pressure? 

[Puffwagon]

I wouldn't add preload at this stage. It'll probably make matters worse.

Get your head around the closed loop control, don't mess with the pids and only use the base table to get a rough approximation of where the wgdc needs to be.

Closed loop can work wonders when set up right.

[JMSMotorsport]

29 minutes ago, Puffwagon said:

I wouldn't add preload at this stage. It'll probably make matters worse.

Get your head around the closed loop control, don't mess with the pids and only use the base table to get a rough approximation of where the wgdc needs to be.

Closed loop can work wonders when set up right.

Not sure if you seen my initial problem but the wastegate DC control is all over the shop, inconsistent. Roland believes this is because I’m asking to much of the solenoid at the high DC required to achieve the higher boost levels from a 10psi gate pressure. Wouldn’t adding pre-load increase my base wastegate pressure allowing less DC therefore giving me back some more control? 

[Puffwagon]

Yeah I've read all the posts. I don't think your issue is related to spring pressure or preload.

In my experience a looser preload is much more controllable in regard to boost spiking.

There is a good way to tune the wgdc table while still using closed loop and you can dial it all in fairly quickly.

Basically the short version is; set the desired boost table, watch the under and over boost effect on the wgdc in the log and set the base table from there. Change the under and overboost settings before the min and max wgdc if needed.

[JMSMotorsport]

Bit of an update, swapped the factory solenoid for a 3 port MAC after doing the wd40 service and powering it up I noticed some leakage and what looked like air bubbles where the plastic port meets the body. Looks like it has a hairline crack at this point. Boost control now works with much less DC. Have found a funny issue thou when I go to Tune2 via CC the desired boost is shown on the log but I don’t get any DC? Swap to Tune3 and DC shows on logger. 

[Roland@pcmtec]

Good find. Desired boost being zero means it is usually in a fault mode or over/under boost. Depends how you've set the two tunes up as well. 

[JMSMotorsport]

1 hour ago, Roland@pcmtec said:

Good find. Desired boost being zero means it is usually in a fault mode or over/under boost. Depends how you've set the two tunes up as well. 

Desired boost shows 10 as wanted but don’t get any DC, copied the DC table to Tune1 Base and it worked, swapped back to Tune2 and it also worked. Very odd. 

[Roland@pcmtec]

Could have overboosted and hit the overboost threshold. Hold it at 4k at steady state on the dyno for 10 seconds in tune 2 and see what happens. 

[Puffwagon]

On 7/27/2018 at 9:20 AM, Roland@pcmtec said:

 

Ok so lets confirm all of these are set and give it another go as lots of people have full open loop working on the FG.

P1227 MIL Lamp

auF1328 P1227 Fault Filter set it to 255

auF1193 P1227 Fault Filter set it to 255

 

Over/Under boost

auF1898 Open Loop duty cycle for underboost set it to something like 40%

auF1679/auF3184 Underboost Threshold - set entire table to something like 40-100

auF0296 Overboost required for open loop - set this to something like -40 to -100

 

PID Gain tables

auF0286 Boost Integral Gain - set entire table to 0

auF0287 Boost Proportional Gain - set entire table to 0

Zero all of these gains

auF16555, auF16567, auF16552, auF16519, auF16453, auF0289, auF0288

 

For good measure set auF16551 TPS vs RPM scaler to 1.0 everywhere other than idle.

edit: From your file it looks like you might be triggering P1227 causing your 0% duty cycle.

 

I've done this before and it worked fine with the stock wg setup.

Today I hooked up my 4 port ex wg into a 3 port solenoid config through the stock solenoid, with boost to the top and bottom of the gate and bleeding off the top.

I got it in open loop and inverted the OL wgdc table to make it work. I did a couple of other things differently given that it wants to be inverted.

With the table at 100% duty it only made 10psi, even though I have 17psi of spring in there. I then tried the table at 80% and it made roughly 25psi up top, but a bit less lower in the rev range. I didn't go further as I'm on 98oct atm, but will revisit it when I switch back to e85 and send it to the moon again.

Is there a way to set up the wg like this and have the boost control work like usual? I think if you had a solenoid that works inversely to the stock solenoid it would work. I also read that hoontune figured something out and have a solenoid etc for sale, although the post was 3 years old.

[Roland@pcmtec]

Yes you can invert all of the boost settings. Eg switch the overboost to be 1 and underboost to be 0. Then invert/flip all the other tables.

Alternatively you could invert the valve as well so it operates in reverse. This might mean it is no longer fail safe however.

[RAWMotorsport]

On 2/27/2021 at 10:39 PM, Puffwagon said:

 

I've done this before and it worked fine with the stock wg setup.

Today I hooked up my 4 port ex wg into a 3 port solenoid config through the stock solenoid, with boost to the top and bottom of the gate and bleeding off the top.

I got it in open loop and inverted the OL wgdc table to make it work. I did a couple of other things differently given that it wants to be inverted.

With the table at 100% duty it only made 10psi, even though I have 17psi of spring in there. I then tried the table at 80% and it made roughly 25psi up top, but a bit less lower in the rev range. I didn't go further as I'm on 98oct atm, but will revisit it when I switch back to e85 and send it to the moon again.

Is there a way to set up the wg like this and have the boost control work like usual? I think if you had a solenoid that works inversely to the stock solenoid it would work. I also read that hoontune figured something out and have a solenoid etc for sale, although the post was 3 years old.

Hi Puff
Did you have another play with that wastegate solenoid configuration?

Im considering attempting to fit a TS IWG75 twin port to my pulsar 3582r to get a wider range of boost control and have a wee scourge around for info before getting into it.

[Puffwagon]

Nah I didn't do anything else with it. I ended up running another wg spring and maxing the turbo out like that.

I had a wg reference line come off while messing around with it, made 45psi in the mid and broke a rocker arm as a result. If the motor wasn't built it would have broken a rod or piston too.

[RAWMotorsport]

9 hours ago, Puffwagon said:

Nah I didn't do anything else with it. I ended up running another wg spring and maxing the turbo out like that.

I had a wg reference line come off while messing around with it, made 45psi in the mid and broke a rocker arm as a result. If the motor wasn't built it would have broken a rod or piston too.

Cheers mate

[hjtrbo]

On 8/29/2021 at 7:53 PM, Puffwagon said:

I had a wg reference line come off while messing around with it, made 45psi in the mid and broke a rocker arm as a result. If the motor wasn't built it would have broken a rod or piston too.

Had something similar happen recently. Had no warning. Albeit significantly less pressure than what you had in your built setup. 

On 7/20/2018 at 2:06 PM, Roland@pcmtec said:

See auF0309 for how much torque is reduced in overboost (I would leave this enabled in case a hose pops off). Torque reduction will be both fuel and spark depending on how your torque source table is set up. 

Then setup your desired boost table to be maybe 10% above what you are generating in cold weather.  Once the overboost threshold is hit auF0296 this will reduce torque by cutting spark, fuel and eventually shutting the throttle completely. These features will save your engine so definitely worth leaving them on and testing that they work.

Then heeded the advice given above by Roland. I adjusted the over boost settings that were disabled by the previous tuner. Not sure why he needed to have this stuff disabled. He also had the boost error cam adder still in play, Muppet... I digress, sorry. Anyway, for my open loop setup, I set the desired boost to 4psi below nominal and ran a test and re enabled the P1227 fault logic. Worked perfect. The stock TM is quite aggressive so you know immediately something is wrong. Works a treat. Afterwards set the table at +2psi above logged nominal winter boost pressure. Hasn't kicked in yet to annoy me, everything is running good.

 

[Roland@pcmtec]

Most tuners disable overboost as a hangover from the old CAPA tuning days. Some even turn off the torque module switch. There was good reasons why this was done 10+ years ago, mostly due to lack of access to parameters. 

The only real reason to do it today -(disabling boost over protection) is lack of time to test the vehicle in cold conditions, lack of time to tune the closed loop PID control or simply due to mechanical reasons (poor wastegate control, eg a BF with a stock flapper and the customer wants 18psi in the mid).

The risk of toasting an engine might be outweighed by random over boost cut outs that occur due to lack of budget for the tune or parts. It definitely takes longer to set this up without causing nuisance cut outs, something that more customers are willing to risk than you might think. 

This said, any tuner should be able to set up the above if time permits and you specifically ask for it. 

We can walk any tuner through this is they have not previously done it and a customer requests it. 

[overlap]

On 1/31/2018 at 4:48 PM, Roland@pcmtec said:

Note this guide is an approximation and may contain errors. Caution should be used when using the assumptions made here. The parameters listed here are for BA/BF only, FG uses different parameter names. A separate guide for FG will be added later.

Boost Control

 

Hi Roland, Has there been an FG How too boost control guide written up yet?

Thanks 

[Roland@pcmtec]

21 hours ago, overlap said:

Hi Roland, Has there been an FG How too boost control guide written up yet?

Thanks 

No. 

It is the same as bf just with the extra tables discussed in this guide. 

 

[Roland@pcmtec]

This is good information worth reading in relation to boost control