In the Ecuflash program there are Max Wastegate duties numbered 1-2-3. What are these used for????

 

I believe its like this
#1 for start up
#2 under normal conditions
#3 when ECU goes to limp mode

 

I've been trying to find out what the effects of changing these are.

Can anyone shed some light on how these are used during tuning?

TIA

 

Thanks Evo Kid, I guess il tune accordingly. My factory duties are set to 100%, for duties 1-2-3. Do you suggest tuning to 75% in any spacific area?

 

"#1 for start up
#2 under normal conditions
#3 when ECU goes to limp mode"

This was proposed for the IX ignition maps, but I've not seen it mentioned for the wastegate duty maps. I think the different maps might be related to gearing from some of the logic used in code that links to these maps. However, in the stock maps this feature appears to not be in use. Needs more work. Meanwhile, I'd be inclined to mirror changes across all three unless you've found that one in particular always seems to be used normally.

 

So Should i not even bother with any of these functions? Let me know...

 

Since they're on 100%, if you're not reaching your load targets you'll need restrictor &/or actuator modification to raise your boost.

 

My understanding is that the "Boost Desired Engine Load" plus the "Boost Control Load Offset" tells the car WHEN to use the BCS; and the "Max Wastegate Duty" tells the BCS HOW MUCH.

The "Turbo Boost Error Correction" attempts to curb the boost up or down depending on if the cars actual load is higher or lower in said RPM range than the target set forth in the "Boost Desired Engine Load" plus the "Boost Control Load Offset."

The stock wastegate duty is set to 100% because Mitsubishi hardwired in (so to speak) the max boost; ie when the wastegate is 100% closed, the restrictors in the BCS and the lack of restrictors in the boost line from the turbo housing, limit the max amount of boost the car can make anyway.

For example, stock is 100% and that allows the stock setup turbo to peak at 19psi.

On a modified car with the boost lines and BCS hoses modified, now you can run (example only, will be different for every car) 45% wastegate duty and get the same 19psi, or raise the duty number to raise the boost.

 

I will post a How To Easily Control Boost (At Your Own Risk) post this weekend. The summary is that it will cost you ~ $5 in parts and will take ~15 minutes and is easily reversible. Boost can be controlled in excess of 30psi and taper can be controlled much better than an MBC.

Parts needed:

(1) 4" vacuum hose
(2) 1 vacuum hose connector (ideally plastic)
(3) A few (3) zip ties


Specialty Tools Needed -- #59 drill bit

I may fabricate a bunch of these and sell them for ~$15 shipped if anyone is interested that way folks don't need to go find a #59 drill bit and misc. parts.

Once the part is installed you will need to adjust your WGDC, boost limit, offset, and error correction (I'll provide recommended starting point). You will be able to control your boost much better than an MBC and easier and cheaper than an EBC.

PM for inquieries / details or part request.

 

Sort of inaccurate there, as it is more the other way around...the wastegate duty cycle sets the boost regulation for the vehicle. this corresponding load is inputted as boost desired engine load + boost load offset. if the load is off + or -, the turbo error correction tables are used to regulate it back accordingly contingent on the loads seen. the 3 maps for boost desired load and max wastegate duty cycle are more gear dependent settings (1/2, 3/4, 5/6*). i believe this was done to counteract the effects of gear dependent loading. also, it seems the ecu has an additonal value it computes for cold start, which kicks in regardless of what values you input in the 3 maps. i confirmed this on the dyno and on the street with my own car.

 

Could it be the minimum boost before operating temp setting?

 

thats what i was leading to...that parameter overrides any setting you input into the boost maps (you would see basically plateuing if u datalogged it)...therfore putting the usual cold start, normal, dtc mode theory to a close (at least for the boost controls). keep in mind thogh that minium temp setting is only a temp related, and there is no value associated with it. that still remains to be uncovered.

 

I could def. be wrong as there is no real information about these settings anywhere to be found. I've been making changes to these settings trying to see what their effects are but it's a long an tedious process. I have not used a dyno because I feel they don't represent real life loading or air flow and therefore aren't a great means to data log. Living in Nevada I have access to some very wide open, no traffic, straight roads which are great for 5th and 6th gear WOT runs. I'm curious about your gear dependent idea on the "Boost Desired Load" maps. I've always thought of them like the fuel and timing; Hi Octane, Low Octane, and Limp. If they are indeed gear dependent settings that's way cool. In that case the boost can be programmed perfectly.

What changes did you make to test your theory? I know that the Wastegate Duty Cycle definitely has control over the boost, but I wasn't sure if it was so much of the "when to control boost" as opposed to "How Much." I know that when I first started making changes to my settings, I wanted to be safe so I set the wastegate duty to 30% across the entire spectrum and it would max boost to 15psi. So I raised the duty to around 45% and it got closer to stock. Then I raised it to 70% and it would boost to 24 psi so I dialed it back.

Then I started to wonder what was telling the BCS when to open and close and how much to open and close. In effect, what setting was telling the car when to add boost and how much, and when to take it away. That's when i started making changes to the BDEL (Boost Desired Engine Load), BCO (Boost Control Offset), TBEC (Turbo Boost Error Correction) and the MWD (Max Wastegate Duty).

I've been beginning to think that, like I posted above, that the BDEL and BCO were the settings that told the car what your target Load was for that given RPM. So say you have 159.4 for the BDEL and 90.6 for the BCO @ 4K RPM's, you're telling the car that you want to hit 250 Load @ 4K. If @ 4K RPM's the load is 240 then the TBEC figures out how much under target and adds to the MWD numbers so as to increase the boost. If it's over target then it takes away duty to decrease boost.

I'm probably wrong, I still have a lot of expiramentation left to do.

On anther note... I didn't think these cars had speed limiters. On two of my WOT runs I got the car up to around 150 and it felt like a very mild fuel cut-off; but then on my last run it was heading north of 160 with no cut what so ever. On my first two runs I started in 5th gear at around 3500 rpm, but on my last run I started in 2nd and worked my way through all the gears. Could the increased Load of starting in 5th have anything to do with a fuel cut? Just curious.

 

ST, have you described elsewhere the results you found from testing each gear and the duty cycle maps used? Sorry if I missed it, if not could you post the details?

 

ST's explanation of the WGDC would explain what I saw -- I put maps 1 and 3 to very low (thinking 1 was cold and 3 was limp) and tried doing 5th and 6th gear pulls and could not get a lot of boost....Then on the way home I tried a 3rd gear blast and it was OK....

I will make changes again and validate later today....Thanks ST!!!!