Cannot get rid of TMA occurring when going from cruising to WOT

[cadillactech]

What boost controller and solenoids are you using? What is the duty cycle you are running them at?

[lynmup]

I am using the AEM true boost x. This occurs at any duty cycle but I haven't went past 40% with my current wastegate spring. It jumps to 15ish but immediately falls back down to 10ish and stays there. I'm trying to target 16psi as that is where I'm getting into fuel limitations.

I had an opportunity to do 1st through 3rd pull and it jumped to 15 at 5,500rpms and went back down to 10 before the shift and stayed there through 2nd & 3rd.

[cadillactech]

I would up the duty cycle and see what that does. If you get the same result, try running it just on gate pressure and seeing if all the mechanical systems work without the boost controller in the mix as a sanity check.

[lynmup]

On wastegate I'm only seeing 10 and with my cut-out open it'll go to 11.5 but it is smoothing consistent. I can't go much further than 40% duty cycle as I'm running into fueling issues. Really don't want to go above a 6.0 pw with so 40% is pretty much the top of my fuel limit.

Adjusting the crack pressure setting is making it go higher or lower but I need to do a bleed test to see where it really opens at to know where to set it but it seems 8.5 PSI is giving me the best results.

I have seen many posts of people not getting full pressure due to exhaust restrictions etc. I have a open non-chambered muffler but even with the cutout it's not giving me full wastegate spring pressure but is consistent.

[lynmup]

It has been a while since I have posted as I have several things I had to correct.

Bad Plugs
Bad plug wires (turbo header clearance issues)
Broken #3 coil wire

After finalizing the above list she is finally running great but I am getting this weird boost spike and PW spike when I go WOT and downshift with E85 that I didn't see with pump gas. This is only happening after final tuning and putting full E85 which is at about 76.5%. Seems there is a table somewhere that controls this but cannot figure out what. I do see an alcohol table called SOI Alcohol tables but when I look at it is it all weird looking with spikes and dips and I cannot figure it out. On pump gas I am able to go up to 20 pounds of boost before hitting the fueling limits and the boost graph is smooth and consistent with my AEM boost controller at 60% duty cycle but with this much E85, I am only able to get to 15-18% duty cycle. Does anyone know of a setting that effects E85 that would correct this spike?

Included a snip of pump gas to show the difference in the boost curve and pulse width compared to the E85 graph. Once this is sorted, I should be finally done with the tuning and can hit a dyno.

[lynmup]

Found a better example, in 1st gear it shows a spike in boost with a very high pulse width but 2nd and 3rd returns to normal and the boost is reflected with the duty cycle I am running. Cant really feel it when you start in 1st as it happens so fast but its there. I have to keep the duty cycle lower to prevent it from spiking too far which is causing the power to suffer in the other gears. I did since adjust the fuel a bit so the .75 is a lil fat in the pic.

[GHuggins]

Well, I can't help a whole lot on this one but if we think about it lean and low timing putting more heat into the exhaust makes a turbo spoil.

[lynmup]

The odd thing is this is only happening with E85. When I first put E85 in it, the mixture was diluted and it was not as prominent but once I got a full mixture, it was worse. I adjusted the shift down to 6,500 and it is livable but would like for it to be gone so I can get more boost for the entire run rather than adjusting it to compensate for this anomaly. I made a small adjustment to the SOI Alcohol Offset table to match a stock corvette and rescaled it to match my engine output. I may have seen a small improvement but need to go out and see if this is effecting that or not. Cannot find any info online regarding that table.

[GHuggins]

The alcohol table adds to the gas table as far as soi goes.

BUT again you went full mix and it started this - lean and low timing makes a turbo spoil. Your pulsewidth is high - you're possibly showing rich from fuel burning in the exhaust helping the turbo to spoil - need to go by soi for that. Plus full E usually needs more timing than lower E...

I find a stock newer ZR1's file is good to use for a lot of boost ideas as it's running a 2650 blower and bigger tb from factory. I actually have some heavily modified ZL1's out there running altered versions of these tables.

Basically pulsewidth needs to be below 5.6ish and watch timing from there.

[lynmup]

I have the alcohol table nailed down from our first discussions so I think I am good there. I did put the SOI a bit lower as the last tuner had it over 360 so I pulled it down to 330 and it helped some but is not fully gone. Would lowering the enrichment ramp in rate a bit help with this as well? Like I said, it is only on the initial hard hit that this occurs, the remainder of the shift is spot on...

Tried to open the file you sent and I am getting this...

[GHuggins]

You have to hook your interface to your computer and be connected to internet to open that file. You need to raise the soi instead of lowering it to keep fuel in the cylinder.

[lynmup]

I went to the truck and got it and can view it now, so comparing the two alcohol tables for PE, I should remove the added fuel at the start? Looking at the stock table and the one you posted it looks like no PE in that range but I did notice that this was set to virtual sensor so it doesn't have E85.

Also cannot copy over the differences. The scaling for the ZR1 is up to 2 g/s, my sock table only covers 1.36 g/s and it won't let me modify the row axis.

[GHuggins]

Copy with axis then hand edit. Sometime you can go into the compare file and copy those particular tables even when it won't let you in the main editor and it will transfer the axis, but certainly not always. Also there may be another table such as the soi that controls those axis in the other tables and you have to copy them from that table.

[GHuggins]

I didn't even look at the pics you posted. Those are the EQ PE tables not the soi tables. Those just control the afr being commanded.

[lynmup]

Not able to edit the row axis using Beta or the latest version. Should I email support for this or would it matter for anything over 1.36 as it would stay the same? SOI Base is not even showing in the compare file as it is greyed out.

Also, should I not worry about adjusting the PE table? You mentioned that it should be lean to get the turbos to spool and I had it somewhat fat in that area.

[GHuggins]

OK, maybe something got misconstrued here

You said your problem was that on full E you were over-spoiling the turbo's - right? Having to kill them which is causing it to not build in the other gears.

So I replied as to what makes turbo's spoil - being lean and low timing

So we then look at the log - you have overly high injector p/w's and from what you said low soi numbers. This is going to cause fuel to go straight into the exhaust = fuel burning in the exhaust causing the turbo's to spoil (I actually use this as a trick on 4th gen turbo setups sometimes) Causes the turbo's to come in hard and quick = a lot more power and torque in the lower rpm band.

What "I would think" you would need to do is to raise the soi numbers - open the zr1 file in a seperate editor and just look it over - it is a PD blower, but mostly the same rules apply. You're looking for your wot fueling to either get richer or for the boost hit to come down. You can also use those E tables and have them zeroed out going into boost.

Hope this clarifies it a bit

[lynmup]

Clear a mud! That is what I had to do is open another editor and do a side by side and add more fuel at the lower spots by following the log and editing where necessary. This what you are alluding to GHuggins?

The biggest issues I have is as soon as the PW starts to spike, is when I hit 1.36g/s. I put in a ticket to support to see if I can modify those parameter's. Anything above 1.36 I cannot control but just comparing files, the ZR1 file has more Injector timing in that area.

[GHuggins]

In the soi table, yes. Increase the soi numbers going into boost. You can try rail pressure increases - that all depends on injectors.

[lynmup]

So why is the ZR1 SOI Base table nice and smooth and the L83 looks like junk?

[GHuggins]

Different compression ratios, different fuel, boost, no boost and so on. I often smooth out the tables but I also work the other tables too that play into it. The stock l83 table for instance is optimized for no boost and it's fuel demands.