No luck with them. B2216 and B2217.

Trying to lift boost at low ECT, I use a 2.0 multiplier with 4 psi, yet, upon logging, there is no added boost , over that seen in the base desired boost table. 2000 rpm cruise and I can't exceed 15 psi max (abs). 20 psi (5.5 psi boost) should be doable.

Also, vanes are at 40% or so, so they are not tasked.

Just not working. Anyone else? Is something limiting boost that I don't see?

By cruise what exactly do you mean? Boost doesn't build when you are holding a constant speed on level ground. When you press the peddle down to the floor under these conditions what kind of boost can you acheive?

Any boost should be obtainable, given enough energy flowing through the vanes to create it. 2000 rpm, 30 mm of fuel, and vanes are at 40%, creating 15 psi abs (1 psi). I am looking for 23 or so, using a base table value of 14.5, plus the low ECT adjustement of 4 (using a 2.0 multiplier).

But it is not trying to produce the boost. despite the table adjustments, it just sits at 15.

Boost doesn't build when you are holding a constant speed on level ground.

It should build, if it is requested, and the energy exists to create it. I believe it does, based on vane position. I don't seem to be running up against vane position table limits.

Here are the applicable tables. You can see I have modified ect boost to come on strong at low ECTs. But it is not showing up on logs

also, is there a "desired" or "expected" boost pid...to compare against actual boost?

Why would you want to spin the the turbo up without it being up at normal operating temp?

I would quit trying to add boost before the engine warms up and concentrate on making the actual boost follow the desired boost table AFTER your truck warms up.

There is a point to it, and a good reason for it, particularly in the winter. The turbo is a great device to use to hasten warmup. I'll be glad to debate this later, but now there is nothing to debate, it is inop.

The problem is that efi puts the table in front of us, but I don't seem to get anything out of it. That also means it is not working as originally intended . Unless I am just not seeing something here.

So does anyone have any ideas?

have you tried adjusting 2218 & 2219

I see what you are getting at. Yes I have them adjusted. But the multiplier is zero at low IAT. I use it as a method to reduce boost at high IAT (again for a good reason) but have not verified whether ot not it is working.

When you press the peddle down to the floor under these conditions what kind of boost can you acheive?

Sorry I missed this. I can command and see well into the 30's , near 40 (again absolute), so I routinely open it up to 25 psi boost

bump

Is it just the ECT multiplier table that isn't working or does the IAT multiplier table have the same problem? I saw you haven't tested it yet but maybe you could to see if there is more than one problem here. Another thought is maybe GM doesn't acutally use these tables.

Is it just the ECT multiplier table that isn't working or does the IAT multiplier table have the same problem? I saw you haven't tested it yet but maybe you could to see if there is more than one problem here. Another thought is maybe GM doesn't acutally use these tables.

I'll test the IAT table today.

The IAT table works fine. I tested each again today, with radical boost enhancements above 25 mm of fuel and -2.0 and +2.0 mulipliers across the spectrum. The IAT table definately enhances/defeats boost. The ECT table definately does NOT.

I have decided Beta testing is not my cup of tea.

The IAT table works fine. I tested each again today, with radical boost enhancements above 25 mm of fuel and -2.0 and +2.0 mulipliers across the spectrum. The IAT table definately enhances/defeats boost. The ECT table definately does NOT.

I have decided Beta testing is not my cup of tea.
Good info even though you still haven't been able to get an answer yet. We have to try things to learn sometimes.

Tech support help please?

EFI staff.

This is an important table to my work. I could really use a hand. Is there any chance you could look into this?

Hmmm. Interesting.;)

I've been running cit1991's v6 economy tune, and I've noticed that it builds more boost when it cold ( < 35) out and the engine is cold than it does when it's warm out and/or the engine is warm.

I'm also playing with cit1991's tune, and I reduced the ECT Timing table factors to reduce boost at cold temps (< 40 F)

i dont know if this help but all i found that needs to be changed is the vanes
and i can get the turbo to do what ever i want.
buff i understand what your trying to do and the vanes wont really change from hot to cold ECT this way but perhaps you just need to change the vanes more to you likeing

if the table doesnt work for you that is a seperate issue:(

buff,
i give it a go when i leave work tonight, ill change it and see i anything changes for me,im not to concerened about this but i might be at some point in my tuning

Thanks Sweetdiesel

update: after adjusting max vane position, some ECT boost enhancement is possible. Just not what is predicted by the math with the multiplier. Further it appears that the vanes are inhibited by factors not shown by the current release.
If I understand what is in front of me, I take the base boost table, B2206, and add the boost found by multiplying the factor in B2217, by the ECT boost found in B2216. The resultant value is what I should see in the log, if the vanes are not at a limit. I have opened up the vane limits, and see minor improvement. But something else appears to be limiting, since vanes are in the 50's, and nowhere near explicit limits.
Or perhaps there is a hard limit on ect boost, or the muliplier limit of 2 to -2 is incorrect, or .... Obviously I can only see 22% of the PCM's storage, so what am I not seeing? I hope this might open the discussion toward understanding the limitations that we few find frustrating. I can see how these peripheral tables may have escaped testing, deferring to performance, that's fine, no argument. This software is amazing in its potential, and there are some other wonderful applications it could find itself useful for, solving issues of constant annoyance, that many have come to treat as... "normal". IMO, this is what really sets EFI apart from the boxes. The difficulty in reverse engineering a PCM does not go unnoticed, I know it is daunting. The added challenge of supporting the more "peripheral" data is also an added load, but it would be appreciated.

Then again, maybe I am just doing something wrong.

well, i tried it
your right, from what i can tell there was no change what-so-ever
i did not didle around i commanded 30 psi also increased the multiplier to 2and there was no change in my normal boost....hmmm

When it comes to vane control it does seem the ECM has a mind of it's own.