Is there such a variable or table in the EVO 8 ROM? I have an EVO 8 with the 96420008 ROM and ECU Controlled Boost with the GM 3 Port.

I have notice in a few occasions that when the car is cold if I accidentally press the accelerator too much the boost climbs way past my set point in the ECU Boost Control. It is like if the car is not doing any correction or using any setting for boost control when the car is cold. And boost climbs like if the WGDC were set at 100% when it is not. I have seen boost of over 25 PSI and then I let off the gas but when the car is at operating temperature I never see more than 23 on the ECU Boost Control Setup.

The logical thing would be to run wastegate pressure when the car is cold but in my case it looks like I am running with no boost control at all. Anyone else have notice this on an EVO 8?

 

How do you "accidentally" press the pedal hard enough to build that much boost on a cold motor?

Just curious.......

 

There is such a variable yes.
I used to think that ECU uses a WGDC map other than #1 when the temp is under the value in the table. But i think this might have been wrong. Although it would make total sense where you can set WGDC at like 40% for example in that table to have low boost when you're warming up.

 

If you are not careful enough you will hit that PSI especially in first gear. It has happened only like 2 or 3 times but I have seen it and can confirm on the hold feature of the gauge. Maybe after a hard day of work I am not 100% aware of this. Thrust me it can happen. I am just trying to find a way to correct this

 

OK so what you are saying is it should be somewhere and that is true because I can replicate the behavior (but I don’t want to). But you do not know where that table or variable is. All my WWGDC tables are the same so that should not be it. It should be something like a min temp to enable boost control. If under that the car just uses 100% WGDC. Maybe I should try logging on a cold engine but I since it is not intentional II don’t have any logs.

 

Yes there is a table that limits WGDC on cold motor/CEL

On 05 and above there is a "Max WGDC vs Coolant Temp" table

On most of the roms there is also a "Max WGDC cold engine/CEL"

Which Rom ID are you using?

 

yes the "Min temp for boost control" variable is WRONG - dont use it

 

My car is an 04 EVO 8 with ROM ID 96420008. If you know the address or how to add it please let me know. I fear my wife will use my car after a cold start and overboost without knowing (its not that hard). I am little paranoid with my car.

 

Thinking more about it has to be a different variable. Why would it overboost only when it is cold if all the max WGDC never change. If it is cold the ROM is not looking at the MAX WGDC tables and is using the max as 100%.

I am not sure if a "Max WGDC vs Coolant Temp" would do it because why only when it is cold. The max on the WGDC are the same for all temps.

Also according to Mr Fred there is no "Max WGDC vs Coolant Temp" in the 96420008. Meybe there is a "Max WGDC cold engine/CEL" but I don't know.

 

Stock boost control system is designed to use 100% WGDC at all times and it does not overboost.

I thought what you're trying to do is to limit your boost on warm-up, to not put stress on the engine until it's up to operating temp and the tables Bryan noted will do just that.

But i reread your first post and i think you may need to retune your boost control. If it shoots over the desired boost all the time on the first pull and doesn't do it afterwards, it may be that you need to lower your WGDC in that area. The reason it doesn't happen on second pull and thereafter may be that you set your error correction negative on your first pull and your WGDC is adjusted lower from that point on.

But that may not be it..

 

The "min temp for boost control" setting is really a WGDC setting. My understanding from looking at the ROM code is that its used when the engine is in limp mode. It may also be used for when the engine is cold as well, but I haven't seen anything that indicates this. If you change the scaling on that definitition from temperature to WGDuty, it should show up as 62.5%. You could try setting it to 10% and see what happens.

 

I just changed the scaling for the "Min Temp for Full Boost Control" to WGDC and it reads 0% stock. The stock value for the Min Temp is 85C wich is 185F very close to a warm up temp on the EVO.

I have not tried changing that value yet. I did not realize it was there until now. Is that definition wrong on EvoScan? The address is 2200 on my ROM.

 

Sorry, a custom definition is needed to read the variable properly please paste this in your ECUFlash ROM xml file:

<scaling name="WGDuty16" units="%" toexpr="x/2" frexpr="x*2" format="%.1f" min="0" max="100" inc="0.5" storagetype="uint16" endian="big"/>

Then change the scaling name in the Min temp for boost control to "WGDuty16". Now it should read 62.5%. If not, then something is still not right with the setup.

 

If the "Min Temp for Full Boost Control" is a WGDC I believe a 62.5% should not let the car boost to over 25 psi (on a GM 3 Port setup). Is that definition doing the same in all the ROMs inlcuding the EVO 8.

 

Have anyone tried changing that variable "Min Temp for Full Boost Control"? What was the outcome? Is it really a WGDC or a Temp?