Difference in throttle percentage

[Alin]

Main question i have is this:

Whats the difference between 80% throttle and WOT?

5th gear WOT overboosted a while back (months ago, havent been WOT since) due to the wastegate crack but on saturday i gave it about 80-90% and maintained 20 psi and had no issues. (My god did it feel good. Havent felt that in a while :lol: )

What changes during WOT compared to any other throttle percentage?
[MENTION=1]IGOTASTi.COM[/MENTION] [MENTION=662]Batmobile_Engage[/MENTION] [MENTION=1507]Spamby[/MENTION] [MENTION=1069]35r[/MENTION] [MENTION=3416]WRB_STi[/MENTION] [MENTION=600]black bandit[/MENTION] [MENTION=652]Grinder34[/MENTION] [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=4577]TK-421[/MENTION]

 

[Batmobile_Engage]

Whats the difference between 80% throttle and WOT?

20%.

:rofl:

 

[Alin]

Well then.... :tard:

Cant believe i didnt know that!

Someone ban him please. :fuji:

 

[black bandit]

The ecu targets different levels based on throttle position. So if you were relatively low load in 5th and went wot it would target probably your max boost. Then your wastegate had to work a lot harder to control the spike in boost with the oncoming load which caused you to overboost.

If you come on it slower, your wastegate doesn't have to work as hard to control the boost and therefore doesn't overboost. Hope this makes sense.

 

[Alin]

The ecu targets different levels based on throttle position. So if you were relatively low load in 5th and went wot it would target probably your max boost. Then your wastegate had to work a lot harder to control the spike in boost with the oncoming load which caused you to overboost.

If you come on it slower, your wastegate doesn't have to work as hard to control the boost and therefore doesn't overboost. Hope this makes sense.

Ok.

Situation 1:
3k rpm i go 50% throttle and gradually increase to 70% until 4.5k then i go WOT.

Situation 2:
3k rpm i go 80% throttle and at 3.5k i go WOT.

Then situation 1 should not spike while situation 2 does spike?

When i spiked a few months back, it was similar to situation 2 but i went WOT at 4k rpm.

I have a few more questions as well but lets get these out of the way first.

 

[black bandit]

No not necessarily, it depends on the gear and load of the car. Really neither should spike too much as long as the interpolation is smooth in your target boost map, which I'm sure they are.

The difference between 80% and wot is probably no more than 2-3 psi. Was it cold when this happened?

 

[Alin]

Has to be due to the crack. Never done it before and georges tune was spot on.

It was 70-80 when i visited [MENTION=662]Batmobile_Engage[/MENTION].

So its all relative to load?

 

[HolyCrapItsFast]

20%.

:rofl:

Good Answer!

 

[Batmobile_Engage]

You honestly haven't been WOT since you were here?!?!?!

I haven't been WOT since 7:15am today. :rofl:

In all seriousness, I guess I didn't understand what you were asking...hence the snarky comment. :lol:

 

[Alin]

Ive barely gone wot in the past year and a half :lol:

Aside from tuning of course.

 

[HolyCrapItsFast]

Has to be due to the crack. Never done it before and georges tune was spot on.

It was 70-80 when i visited @Batmobile_Engage.

So its all relative to load?

Yes. load is the key. And the ability for the GD to react to spikes in boost are adjusted with turbo dynamics proportional and integral gain settings. There is no per-gear tables like in the GR-GV so we have to do things the old fashioned way.

The effect of spiking or over boost can be minimized if we tuned the gain settings but I'm lazy and don't want to :lol:

 

[Alin]

We will just wait until the nee turbo is in! :ty:

At least i can do 80% now. :rofl:

 

[black bandit]

Was it the p0244 code?

 

[Alin]

Ah i dont remember the code but it was for wastegate solenoid.

 

[black bandit]

Ah i dont remember the code but it was for wastegate solenoid.

Yes that's the same code.
[MENTION=9]HolyCrapItsFast[/MENTION] couldn't you bump up his max wgdc limit in the range that he overboosted? As long as his wgdc isn't close to the max?

I know some tuners will use the max wgdc table as a backup to overboost and set them sensitive.

 

[WRB_STi]

Turbo is done. :subaru:

 

[WRB_STi]

What are you using for a boost controller?

Also, have you considered a hybrid controller?

 

[Alin]

Grimmspeed 3 port ebcs

 

[HolyCrapItsFast]

Yes that's the same code.
@HolyCrapItsFast couldn't you bump up his max wgdc limit in the range that he overboosted? As long as his wgdc isn't close to the max?

I know some tuners will use the max wgdc table as a backup to overboost and set them sensitive.

Max WGD isn't really going to fix over boosting at least in my tuning strategies. If the car is over boosting, the system is going to strive for a lower waste gate duty, and adversely the more load, the more the turbo is going to want to produce more boost. They kinda fight each other. Since the WGDC tables don't reference load we need to rely on turbo dynamics gain settings to set the change rate under different conditions.

In a way you could manipulate the Initial and max WGDC table to achieve less of an effect but you need to find a balance because if the difference between the two is to small, then you won't hit target in lower gears or not at all and if the difference is to great, then you will certainly over boost more easily.

The system will always look at the Initial WGD table first and apply those settings. Then if it needs more, it references the Max WGD table and applies more waste gate duty up to the max. The Gain tables limit or manipulate the rates at which that occurs, so the gain tables will have more of an effect on over boosting and spiking issues

 

[TK-421]

Max WGD isn't really going to fix over boosting at least in my tuning strategies. If the car is over boosting, the system is going to strive for a lower waste gate duty, and adversely the more load, the more the turbo is going to want to produce more boost. They kinda fight each other. Since the WGDC tables don't reference load we need to rely on turbo dynamics gain settings to set the change rate under different conditions.

In a way you could manipulate the Initial and max WGDC table to achieve less of an effect but you need to find a balance because if the difference between the two is to small, then you won't hit target in lower gears or not at all and if the difference is to great, then you will certainly over boost more easily.

The system will always look at the Initial WGD table first and apply those settings. Then if it needs more, it references the Max WGD table and applies more waste gate duty up to the max. The Gain tables limit or manipulate the rates at which that occurs, so the gain tables will have more of an effect on over boosting and spiking issues

1st I personally agree with [MENTION=9]HolyCrapItsFast[/MENTION] the boost control system when utilizing either a stock BCS or a 3 port like the GS. With the stock system it's a little less complex, but essentially what needs to happen is the WGDC needs to work in a linear fashion, you can't expect the turbo to create max boost pressure and for it to be solely regulated by just the wastegate. Being the fact that [MENTION=1172]Alin[/MENTION] has a 3port GS EBCS it operates in a different fashion compared to the Stock EBCS. The Stock EBCS runs in a bleed mode where it allows the wastegate to read all of the boost pressure at first and then bleeds off the excess back into the turbo inlet pipe just before the turbo, which is why some people tend to hear a flutter type of noise, it's the excess pressure being pushed back into the inlet. The Grimmspeed on the other hand runs in a interrupt mode where the wastegate literally sees zero boost pressure so at first the turbo will have a much higher level of initial response compared to the stock system, which is why the wastegate duty cycles both high and low and the turbo dynamics proportional mapping must be scaled to the proper settings, if just the wastegate duty cycle was adjusted to compensate for the initial turbo responsiveness there would be too many fluctuations in boost level which would result in either a over boost or under boost condition, depending what load compensation table is selected by the ECU.

Below ow is a small video covering the basics of tuning the boost control system using the Cobb ATR explained by FASTuuN

http://youtu.be/2zufnLglnpY


And second, I do apologize in advance for any delays in response to threads, I am preparing to make a road trip to Virginia Beach, I learned earlier today that my grandmother passed away and I must attend her funeral on Friday. So sorry [MENTION=1172]Alin[/MENTION] if I'm unable to answer any mentioned posts