Have a couple quick questions about this ecu controlled boost fiasco lol. Im still playing with boost, and have learned quite a bit about tuning it in the ecu. I have it figured out how to raise it, relatively. I just cant combat against all this taper. Im getting it to hit 1.5 bar or so which is about what I want, but it tapers to 1.2 by 7k. I have a works hose, so with their flash I was able to hit 1.4 and hold it to redline with no taper. That part is worked out. But going higher induces way too much taper, so...

My question is this...should I set turbo boost error correction to zero'd out? Ive noticed that playing with that makes boost go up and down a touch.

What I have now is lower error correct numbers on the neg side (-6.5), wg duty set to 56 from 3k on, load offset at 130, and desired load 138.1 across the board. This was set from a modded euro RS map and I copyed it over. Ive played with my map plus a few others.

I figured out if I play with load offset it will increase or decrease boost linearly. Im thinking that desired engine load will do the same thing. While typing this I started thinking, what if I gradually increase desired engine load up from 130 thru to redline? Any insight would help on this.

I know John, JCS and Evo_Kid have been playing with this quite a bit!

 

load offset + desired load = target load cell on your map

Max WG Duty + error correction = actuall wg duty

For example:
If you want to hit 240 load cell at 3500 rpm and 200 load cell at 7000
set desired load to at 3500 to 130 and load offset to (240-130) = 110
set desired load at 7000 to 90 (200-110)= 90
then do a vertical tapper from 3500 to 7000.

Does that help any?

 

Im following you on the load. The only thing you lost me on was the vertical taper. from 3500 to 7000. Did you mean on my wg duty, taper those upwards? (example: 50's in 3k up to 80's at 7k type thing). Also, zero out error correction?

 

What doesnt make sense to me is if I have all my desired load set to 159.4 + 80 for load offset to put me in 220/240 cell, all my wg dutys are set at 50 from 3k up to 7k, 0 on error correction, why it tapers. It would make sense to taper if my desired load decreased as my rpms raised. Lower load would seem like less boost to me. This is what is boggling my mind. The way I look at it seems right, yet it still tapers down

 

Isn't 50 WG duty cycle keeping the Wastegate solenoid closed more often? Try Maxing out the WG Duty Cycle to 127.

 

A few quick questions before I start giving advice. Do you have the stock restrictor pill in or does that get altered with this WORKS hose you have? I dont know anything about that particular product so bear with me.

All I can suggest is curve your boost limit and WG duty cycle towards max by redline. For instance it could look something like this (this is by no means gospel I am trying to illustrate):
..............WG D/c.......Boost
4500........50..............138
5000........55..............148
5500........60..............153
6000........65..............157
6500........70..............159.4
7000........75..............159.4
7500........80..............159.4

Or some such.

I can personally tell you mine is setup completely different than most and it works well for me. You will always have some taper as VE improves and air requirements cant be kept up with at higher rpm. 1.5 down to 1.2 Bar is more than you should see though. It should be able to maintain almost 1.5 (not on the factory gauge disregard it) all the way to redline though with a properly curved map.

John

 

Works flash comes with a new boost hose, the whole "T" actually. Supposedly has a new restrictor in it.

Ya I'll give that a try. Thats similar to my works flash actually, except the works is 94.5 at 7500 with 159.4 desired. I havent tried bumping the duty cycle past 100 up to 127. Thats my next course of action.

John, any chance I could persuade you into sending me your map? I can offer an IX FQ340 map Ive been playing with in return, or a modded euro RS map!

speedy213@***.net if anyone wants to exchange

 

John's suggestions are sound. I would suggest 100% on the solenoid from 5000 or 5500 RPM up, just check you don't overboost on a gearchange.

My AVC-R map is as follows:
Boost targets:
up to 5000 1.65
5500 1.60
6000 1.55
6500 1.50
7000 1.45
7500 1.40

Duty cycles:
up to 3000 90%
3500-5000 65%
5500 70%
6000 upwards 90%

The AVC-R uses a 3 port solenoid, but there is no reason the duty cycles wouldn't be wildly different in shape with a stock 2 port solenoid with restrictor and hose changes like you have.

I'm fairly convinced that I have everything the turbo can safely give on the pump fuel I use. I let it overboost to see peaks up to 1.80kg/cm^2.

Note that the loads I hit as RPM increases diverge from the absolute manifold pressure. This is the drop in VE, so it might only hit 220 or 230 at high RPM when you would expect 240 from the boost.

I have a IX FQ340, but the previous owner had a crap Ecutek map flashed over the top of it. I would really like to see a standard IX FQ340 map if you have it. johnbanks@dsl.pipex.com

I previously posted my maps on openecu under my tag s54fan. However, it wasn't a boost control map as I use the AVC-R and just played briefly with the AVC-R solenoid connected to one of my JDM/UK twin solenoid channels.

 

I need to look at more disassembly when I have time, but I believe that 100 is still the maximum duty cycle worth putting into the duty maps. Also the result of the error correction map is a ramp rate up/down that is applied to the duty cycle. It is not simply added on when this boost error is seen. That would be a proportional only system - it behaves like an integrator with gain based on the boost error - ie a sort of PI system.

 

Ahh, So that makes sence. From reading the previous discussions I thought the error correction was an additinal duty cycle allowance.

An additional note:

You can rescale the Max WG Duty cycle maps rpm column if you need more granular control in a particular area. For Example:


Stock
500 100
1000 100
1500 100
2000 100
2250 100
2500 100
2750 100
3000 100
3500 100
4000 100
4500 100
5000 100
5500 100
6000 100
6500 100
7000 100

Current
500 90
3500 90
4000 91
4250 91
4500 94
4750 91
5000 91
5250 91
5500 92
5750 90
6000 90.5
6250 90.5
6500 91
6750 91.5
7000 92
7500 92.5

I Was able to get very repeatable results this way. I only spike about .5 psi over what it hold from 4k-6k and then tappers smoothly about 2psi to readline, which is what I wanted.

 

You can always zero out the error correction, and get the boost where you want it using the WG Duty. After you get it where you want it, determine your load throughout the rpm range, and plug those load values in the Boost Desired Engine Load(desired load minus Load Offset) maps. Fill the Error correction map back in, then check to make sure that your boost is still where you want it.

 

^ excellent suggestion for getting it smooth.

 

Someone explain the desired load more.

I thought load was just how much load was on your car. Like if you going up a hill the load would be more. What does the deresied load do, is that where the ECU would like the load to be before it enable full boost control or something. What if it doesnt hit the dersired load, does it not give frull boost control. I understand how you guys are saying to set it, but do get what its doing.

 

Think of load as proportional to air mass per cylinder event. In some ways comparable to boost, but affected by temperature of the charge, and volumetric efficiency of the engine.

 

^^

Thant didnt help at all. I know what load is. tell me how desired load relates to boost.
If you can answer some of my questions in my other post.