Yes, or if you are like me and tune a bunch of different evos every week you can just switch the scaling back and forth on the "Alternate Boost Desired Engine Load" map depending on what type of boost system you are tuning and if you are using alt maps or not.

 

thanks tephra. hopefully i'll have time this weekend to play with the car and see what i can do with v5

 

no prob's

RL I just created a new catagory - "Direct Boost" and had duplicates of all the tables in there.. so I could see both BDEL (in the Turbo cat) and Target Boost (in the DB cat)...

 

I think it was discussed once before but only briefly so I would like to again bring up the idea of gear dependent boost control.

The idea was to assign BWGDC #1 to gears 1&2
BWGDC #2 to gears 3&4
BWGDC #3 to gears 5&6

What do you guys think about this idea. I have done a fair bit of tunning with the direct boost control system, and while I have managed to achieve pretty good results I always find that it is a compromise between reaching maximum boost in lower gears and not over-boosting in higher gears.

I know Tehpra is working on a PID boost control system but I don't really know what his goals or methods for the system are going to be, maybe something of this nature can be included. Does anyone have a link to a post where Tephra outlines the goals of the new system?

 

I think it is a band-aid. I'd rather have a full PID controller or at least a 3d map with all the tables. It would be quite annoying tuning different gears in different tables.

 

my goals are simple.

a boost control system that doesn't spike (much) and reacts the same in all gears

 

i.e. what the car should have came with

 

Sound like some good goals to me.

I don't know all that much about PID controllers but from what I can gather I believe what we have is a P controller if I'm not mistaken. Is it reasonable to assume that by simply adding I and D values into the equation we can achieve such a boost control system? Forgive me if I'm saying something silly or obvious but I am just trying to understand exactly how you will achieve an accurate boost control system.

From Wikipedia

 

basically we need our boost control to take in more variables. A full 3d map of RPM, WGDC and load or TPS would really help.

 

Correct me if I am mistaken, but I think that would still be a P controller. You would just be using more inputs in calculating the P value.

 

basically when its done you will have a 2d or 3dmap with RPM on the Y and throttle on the X and target psi/load as the map..

you wont need or be able to specify the wgdc...

I have started the code but havn't had to time to debug it properly..

 

nevermind.

 

Its closer to an I system. The WGDCC is the I value. I do like the idea of a PID system, but I think the OEM system gets a bad rap. It lacks a few features not related to PID control, but otherwise can be made to work very well.

 

Quick question. What happens if you are in third or fourth at 4K RPM with very low boost (light on pedal) and hit it WOT (like in a freeway run) when you overshoot boost by more than 3 you will correct with a -18% WGDC your boost will drop and will never come back because anuthing less than -1.4 is zerod. Is that right? Thats what happening to me with the load based setup on a sudden freeway pull that overshoot boost.

 

you got it, but on the current system its the best you have got.... otherwise you are overcorrecting way to much on spoolup... you just have to remember not to stab it in 5th unless you want to be stuck under your threashold (~18psi is not so bad IMO)