How to use the High and Low WGDC Tables

**Siegel Racing** · 08-31-2005, 04:27 PM

I almost feel I should apologize for not explaining this earlier, but I thought it was in the ST instructions or something:

The "Low WGDC" table in ST is the same as the "Initial Wastegate Duty" table in Ecutek. The "High" is the same as the "Max."

The short and sweet of it is that the car can roughly:

ADD 10%
or
SUBTRACT 50%

to/from the values in the Low map.

I know this may be a totally different paradigm than what some people were thinking, but if you like, try it. Actually in this forum, I know you will all try it

I've never set the High to lower than the Low, but within reason all that really happens is that car can add 10% or subtract 50% from the Low.

There have been times that I have seen it not want to break over my High setting, but for the most part it will blow right through it, up to approximately 10% over the low.

The WRX's only have High/Max maps so when the STi came out everybody used the Max like they had on the WRX's and set the Low 10% under that. If you do it that way it will appear that the car can run from 60% under the Max up to it. But if the "Initial" is a good description than I like to hope that "as soon as your foot hits that throttle position at that rpm, the car goes to the initial wastegate setting and runs turbo dynamics (gains) from there."

I thought, hmmm, what if I set the Low to only 8% under the High, will it respond faster? Well it did, and it blows right through the high number, up to 10% over the Low (assuming it's still under desired boost).

If you are running under 50% in the low map it will sometimes add over 10% to the low, and on some occassions I have seen it not run over the max even when actual boost was lower than desired.

I made a pretty excel table that takes the whole Low map and "creates" a High map with all the numbers exactly 8% over the low. I haven't had to think about it since

This is another advantage to the Perrin EBCS: you generally use NOTABLY lower WGDC's with the EBCS and it has more "authority." Therefore with the lower numbers in Low, it can go lower overall . IE if you had 80% to make 14 psi on the stock selenoid, in creep situations it can only go down to 30% and even then there is the restrictor, with the EBCS you might have 60% in there so it can go down to 10% with no restrictor.

Let me know if this works for you. (paypal me Chipolte money if you are really happy

)

SS

the blue thing · 08-31-2005, 07:37 PM

wow thanks for the info, I was playing with the ST 5 mins ago before reading your post. So do you suggest people remapping the WG DC low at all? or do we just simply make the WG DC low 8% higher than the WG DC high

cnstman · 08-31-2005, 07:52 PM

so wait, what is the high for then if the ecu will only go 10% over the low?

**Siegel Racing** · 08-31-2005, 10:50 PM

Not sure what the high really does... it appears to be semi-worthless...

set the Low 8% UNDER the High...

SS

WolfPlayer · 09-01-2005, 03:34 AM

I've seen my car go 20% over the low.

The high semi-worthless? Definitely not for me. Data logs showed 75% DC in the upper regions corresponding to Cobb's stage 2 map. All I did (initially) was to raise values in the 'high' table and the WGDCs jumped up immediately.

So far, my experience is showing things that are against what you said. 20%+ over the low Wastegate map and my high wastegate map being totally useful in allowing the WGDC to raise up.

I look at these maps like a window ... but a window that has modifiers added/subtracted to it depending on weather, altitude, etc.

t

jays05 · 09-01-2005, 04:35 AM

I'm not sure what to think here, I'll have to do some more testing this weekend. My logs also seem to stick to the High map values at WOT, however I found that tuning the Low map made the car a lot more responsive. I have 40% in my Low map at 3200 and 3600, and I see 52-53% in my logs, which matches up exactly with the High map.

WolfPlayer · 09-01-2005, 04:49 AM

Quote:

Originally Posted by jaygoesfast

I'm not sure what to think here, I'll have to do some more testing this weekend. My logs also seem to stick to the High map values at WOT, however I found that tuning the Low map made the car a lot more responsive. I have 40% in my Low map at 3200 and 3600, and I see 52-53% in my logs, which matches up exactly with the High map.

So, Jay, you are seeing 12-13% above the low .... and I can pretty much guarantee that if you raise the high value then your WGDC will jump up higher than 12-13%. I think Scott's figure of 10% doesn't take into account something. It might be fine for where he is located (environment)? -- but it just doesn't work like that on my car. An easy test for you would be to lower the LOW wgdc map. It will still try to reach the high value and will go above 10% trying to get to it.

t

**Siegel Racing** · 09-01-2005, 10:56 AM

I said that if your low is near or under 50% it will overshoot by more than 10%, but not usually much more.

The other "qualifier" is that it can only change at a certain rate. If you have 80% in one cell, and 50 in the next it won't get down to 50 that fast.

I'm dying to see what results come from this stuff...

For those that want to experiment. Try setting your whole low map to 40%, and you're whole high to 60%... see what happens...

As I said, WITHIN REASON I have not found much outside the add 10 or subtract 50 from low...

SS

WRX_XB9R · 09-01-2005, 12:44 PM

I have taken the rescaled Wolfplayer map and added to the HWGDC map to get my boost up. I am currently at 15% above the LWGDC map. It runs fairly close to the High map. This is 13 to 15% above the Low map. My settings are 70 for low and 85 for high. I did test at 20 to 25% above the Low map but I could build no more boost at higher rpm. I dialed back the High map to a manageable level.

However maybe I need to add some more to the low map in the upper rpm range so that I can increase the boost more easily. Also adding to -8% may make the boost spool more quickly.

More CMT is needed.

WolfPlayer · 09-01-2005, 04:44 PM

Quote:

Originally Posted by Subaru of Gwinnett

For those that want to experiment. Try setting your whole low map to 40%, and you're whole high to 60%... see what happens...

Check out some of the other posts on this board. I did that less than a week ago ...

Experiments with WGDC (low) map

t

**Siegel Racing** · 09-01-2005, 06:44 PM

Just like Christian said, he sets the high to 5-8% over the low. At that point there is no mystery... a few other tuners set their low to 5 under the high, I use 8 under... I still feel like the high is close to worthless - if you set the high near 8 over the low, the car will run from 50 under the low to 10 (or so) over...

SS

WolfPlayer · 09-02-2005, 03:11 AM

Quote:

Originally Posted by Subaru of Gwinnett

Just like Christian said, he sets the high to 5-8% over the low. At that point there is no mystery... a few other tuners set their low to 5 under the high, I use 8 under... I still feel like the high is close to worthless - if you set the high near 8 over the low, the car will run from 50 under the low to 10 (or so) over...

SS

Now that makes a lot of sense to me. Yea, if your low is only under the high by 8% then you'll only see about a ~10% increase .... which is the 8% to get up to the high 'cap' + some value (2% in your case) for environmental conditions.

1) How do you ensure you get no boost creep with only an 8% difference?
2) Are these numbers for the Perrin EBCS? If so, then don't both answering #1 because I know the answer.

t

**Siegel Racing** · 09-12-2005, 06:29 AM

Creep is a TOTALLY different issue. On one hand all you need to do is make sure that there is "room" to go low enough duty to prevent it.

The ecu appears to be able to add 10% or subtract 50% from the low to do what it needs. As long as 50% under the low is low enough, there shouldn't be creep.

Honestly creep has not been much of an issue lately. It might come back to the forefront again when it gets cooler. I've gotton more aggressive with the temerature to wdc adjustment tables... when it falls under 50 F i start to remove wdc.

I use the 8% offset on both EBCS's and stock selenoids.

I haven't even looked lately, but the FXT's maps have the high exactly 7% over the low in the entire map...

I bet they consistenly overshoot their High by 3%

SS

cnstman · 09-14-2005, 06:54 PM

did some logging tonight, my low is 25, my high is 30. i see values from 27-36 in my logs. that is up to 44% above my low.

probably has to do with the fact i am at 6000' and my boost targets are higher than the turbo can run. even with my 18 g and 15 psi wastegate can, my boost tapers to 15psi at redline. this is with a ebcs in interrupt mode.

**Siegel Racing** · 09-14-2005, 07:17 PM

I meant 10% wastegate duty, as in 25+10 = 35, however I also said that if low is under 50% that it sometimes adds a bit more

25+11 = 36

SS

09-14-2005, 07:17 PM	#15
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	I meant 10% wastegate duty, as in 25+10 = 35, however I also said that if low is under 50% that it sometimes adds a bit more 25+11 = 36 SS This ad is not endorsed by this member. Please register or login to hide this ad.

08-31-2005, 04:27 PM	#1
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	How to use the High and Low WGDC Tables I almost feel I should apologize for not explaining this earlier, but I thought it was in the ST instructions or something: The "Low WGDC" table in ST is the same as the "Initial Wastegate Duty" table in Ecutek. The "High" is the same as the "Max." The short and sweet of it is that the car can roughly: ADD 10% or SUBTRACT 50% to/from the values in the Low map. I know this may be a totally different paradigm than what some people were thinking, but if you like, try it. Actually in this forum, I know you will all try it I've never set the High to lower than the Low, but within reason all that really happens is that car can add 10% or subtract 50% from the Low. There have been times that I have seen it not want to break over my High setting, but for the most part it will blow right through it, up to approximately 10% over the low. The WRX's only have High/Max maps so when the STi came out everybody used the Max like they had on the WRX's and set the Low 10% under that. If you do it that way it will appear that the car can run from 60% under the Max up to it. But if the "Initial" is a good description than I like to hope that "as soon as your foot hits that throttle position at that rpm, the car goes to the initial wastegate setting and runs turbo dynamics (gains) from there." I thought, hmmm, what if I set the Low to only 8% under the High, will it respond faster? Well it did, and it blows right through the high number, up to 10% over the Low (assuming it's still under desired boost). If you are running under 50% in the low map it will sometimes add over 10% to the low, and on some occassions I have seen it not run over the max even when actual boost was lower than desired. I made a pretty excel table that takes the whole Low map and "creates" a High map with all the numbers exactly 8% over the low. I haven't had to think about it since This is another advantage to the Perrin EBCS: you generally use NOTABLY lower WGDC's with the EBCS and it has more "authority." Therefore with the lower numbers in Low, it can go lower overall . IE if you had 80% to make 14 psi on the stock selenoid, in creep situations it can only go down to 30% and even then there is the restrictor, with the EBCS you might have 60% in there so it can go down to 10% with no restrictor. Let me know if this works for you. (paypal me Chipolte money if you are really happy ) SS This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by Siegel Racing : 08-31-2005 at 04:42 PM.

08-31-2005, 07:37 PM	#2
the blue thing Amateur STI Driver Car: 04 Subaru WRX STi Fav Mod: Coming Soon Location: Canada Posts: 48 Join Date: Jul 2005 Trader Rating: (0)	wow thanks for the info, I was playing with the ST 5 mins ago before reading your post. So do you suggest people remapping the WG DC low at all? or do we just simply make the WG DC low 8% higher than the WG DC high

08-31-2005, 07:52 PM	#3
cnstman Spec C Club Car: 04 STi Fav Mod: GT-35R Location: Colorado Springs Posts: 1,326 Join Date: Jan 2003 Trader Rating: (2)	so wait, what is the high for then if the ecu will only go 10% over the low?

08-31-2005, 10:50 PM	#4
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	Not sure what the high really does... it appears to be semi-worthless... set the Low 8% UNDER the High... SS

09-01-2005, 03:34 AM	#5
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,620 Join Date: Jun 2004 Trader Rating: (6)	I've seen my car go 20% over the low. The high semi-worthless? Definitely not for me. Data logs showed 75% DC in the upper regions corresponding to Cobb's stage 2 map. All I did (initially) was to raise values in the 'high' table and the WGDCs jumped up immediately. So far, my experience is showing things that are against what you said. 20%+ over the low Wastegate map and my high wastegate map being totally useful in allowing the WGDC to raise up. I look at these maps like a window ... but a window that has modifiers added/subtracted to it depending on weather, altitude, etc. t

09-01-2005, 04:35 AM	#6
jays05 Spec C Club Fav Mod: when it's not blown up Location: Upstate NY Posts: 1,564 Join Date: Nov 2004 Trader Rating: (0)	I'm not sure what to think here, I'll have to do some more testing this weekend. My logs also seem to stick to the High map values at WOT, however I found that tuning the Low map made the car a lot more responsive. I have 40% in my Low map at 3200 and 3600, and I see 52-53% in my logs, which matches up exactly with the High map.

09-01-2005, 10:56 AM	#8
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	I said that if your low is near or under 50% it will overshoot by more than 10%, but not usually much more. The other "qualifier" is that it can only change at a certain rate. If you have 80% in one cell, and 50 in the next it won't get down to 50 that fast. I'm dying to see what results come from this stuff... For those that want to experiment. Try setting your whole low map to 40%, and you're whole high to 60%... see what happens... As I said, WITHIN REASON I have not found much outside the add 10 or subtract 50 from low... SS

09-01-2005, 12:44 PM	#9
WRX_XB9R Professional STI Racer Car: 04 WRB/ GOLD STI Fav Mod: snail sticker = 5hp Location: Raymore, MO Posts: 792 Join Date: Feb 2003 Trader Rating: (0)	I have taken the rescaled Wolfplayer map and added to the HWGDC map to get my boost up. I am currently at 15% above the LWGDC map. It runs fairly close to the High map. This is 13 to 15% above the Low map. My settings are 70 for low and 85 for high. I did test at 20 to 25% above the Low map but I could build no more boost at higher rpm. I dialed back the High map to a manageable level. However maybe I need to add some more to the low map in the upper rpm range so that I can increase the boost more easily. Also adding to -8% may make the boost spool more quickly. More CMT is needed.

09-01-2005, 06:44 PM	#11
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	Just like Christian said, he sets the high to 5-8% over the low. At that point there is no mystery... a few other tuners set their low to 5 under the high, I use 8 under... I still feel like the high is close to worthless - if you set the high near 8 over the low, the car will run from 50 under the low to 10 (or so) over... SS

09-12-2005, 06:29 AM	#13
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,239 Join Date: Mar 2005 Trader Rating: (2)	Creep is a TOTALLY different issue. On one hand all you need to do is make sure that there is "room" to go low enough duty to prevent it. The ecu appears to be able to add 10% or subtract 50% from the low to do what it needs. As long as 50% under the low is low enough, there shouldn't be creep. Honestly creep has not been much of an issue lately. It might come back to the forefront again when it gets cooler. I've gotton more aggressive with the temerature to wdc adjustment tables... when it falls under 50 F i start to remove wdc. I use the 8% offset on both EBCS's and stock selenoids. I haven't even looked lately, but the FXT's maps have the high exactly 7% over the low in the entire map... I bet they consistenly overshoot their High by 3% SS

09-14-2005, 06:54 PM	#14
cnstman Spec C Club Car: 04 STi Fav Mod: GT-35R Location: Colorado Springs Posts: 1,326 Join Date: Jan 2003 Trader Rating: (2)	did some logging tonight, my low is 25, my high is 30. i see values from 27-36 in my logs. that is up to 44% above my low. probably has to do with the fact i am at 6000' and my boost targets are higher than the turbo can run. even with my 18 g and 15 psi wastegate can, my boost tapers to 15psi at redline. this is with a ebcs in interrupt mode.