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Once you capped the red line, the wastegate signal became irrelevant... you neutered that control signal. Taking infrequent samples of the wastegate PID leaves you with a long duration of the last sampling - making it appear to stay high or low for a long time (right through changing events).
I see you now have a significant gain in EBP and boost, but I also see leaks. You'll need to go on safari for boost and exhaust leaks - sorry.
I know I have to continue to hunt down leaks. I also want to check other possibilities in parallel.
Sorry if this is a bit random - I just wanted to get it out there....
I also need to step up may game some because it seems like it might be getting worse. Doing WOT runs with not much load I have been seeing MAP values of 28-29.5 or so. This is near red line on RPMS.
Pulling a trailer, at about 2300-2400 RPMS I'm seeing a max MAP of about 27. I **assume** that with now load at the higher RPM that the truck actually requires less air/fuel than the truck WOT at 2300 RPMs going up a hill. Does that seem reasonable?
One thing that confuses me is exhaust leaks. At max boost / WOT the wastegate "hole" is pretty big. It seems to me that as long as capping the red hose produces a larger difference in EBP vs uncapped that any exhaust leak will be overshadowed by the wast gate hole.
One other thing that I noticed is that my filter minder is starting to move. It's still much closer to the new side vs the replace side, but I wonder if it could be restricting the air flow enough have an impact. Might that explain being able to make more boost with a low load vs a high load?
When doing these WOT runs, do I want to take my foot out of it as soon as I see 1200 on the EGT gauge?
Wastegate "hole"? With red line capped, it's now more of a wastegate "wall" - it's closed.
RPM redline? are you referring to another log? RPMs don't even reach 3000 on your graph. Redline is about 3250.
The "experts" say you can run your EGTs at 1250 (EGT redline) for a max of two minutes. There are a lot of variables at play, so it's an estimate. The concern is not a blast of hot air, the concern is "heat soak".
Heat soak: Light a lighter and just wave it by your palm at a distance of one inch. That's a WOT run, then a let-up. Now... hold that lighter under your palm for 5 seconds (in your imagination only - for readers that take everything literally). That's heat soak, that's damage, and that's like going up a grade for 5 minutes with EGTs at 1300 degrees while towing. Hot air is not the the thing, overheated metal is.
Boost/exhaust leaks make higher EGTs much easier than a sealed system. Fix the leaks, then revisit everything.
Wastegate "hole"? With red line capped, it's now more of a wastegate "wall" - it's closed.
Agreed. What I'm trying to say is that if it's possible to generate way more exhaust backpressure with the waste gate capped vs uncapped then any leak that might exist must be small in comparison to the virtual leak created by the wastegate. There must be some number (spread between max EBP plugged vs unplugged) that helps to gauge leaks on the exhaust side. For example if EBP can get typically get to 45 PSI with the WG plugged and 30 PSI with the WG unplugged, then the spread is 15PSI. If I can only make a spread of 7 PSI, then maybe I have a problem on the exhaust side. If I'm seeing 15PSI then I probably don't need to focus on exhaust side leaks.
I don't know if the above concept works, but it seems like something along those lines should.
Originally Posted by Tugly
RPM redline? are you referring to another log? RPMs don't even reach 3000 on your graph. Redline is about 3250.
Sorry. The above chart is just to show getting out of the throttle when EGTs hit 1200 or so.
My observation is that:
a) WOT at redline at ~55 MPH (at the 2nd to 3rd gear shift I think) I can seem MAP values of 28-29.
b) WOT at ~60MPH towing a trailer at 2500 RPMS I see a map more in the 26-27 range. Now this not apples to apples to a) but this operation is more real world (WOT pulling a hill at 50-65 mph).
I'm just wondering if there is anything the be learned by the difference between a and b other than higher RPM = More Boost?
Originally Posted by Tugly
The "experts" say you can run your EGTs at 1250 (EGT redline) for a max of two minutes. There are a lot of variables at play, so it's an estimate. The concern is not a blast of hot air, the concern is "heat soak".
Thanks, this is the magic number I was looking for. I get the heat soak issue too.
Originally Posted by Tugly
Boost/exhaust leaks make higher EGTs much easier than a sealed system. Fix the leaks, then revisit everything.
I've fixed every leak that can be found with the exception of a small manifold leak. Given that fixing a **much larger** up pipe leak changed nothing, I'm not too concerned about the pinhole (or smaller) manifold leak at this point. It seems like I have bigger fish to fry.
I'm just wondering if I'm chasing red herrings here. For example would it be possible that I can't hit max boost simply because my 5 year old AIS filter is a little clogged and the engine simply can't get enough air to make max power?
Stock tuning with some air mods and the red line capped:
I would focus exclusively on the anemic boost before I moved onto the EBP sensor. While the sensor is likely bad, that sucker ain't cheap.
Was this your stock hpop after a rebuild or still untouched? After how many miles too? I dont think my hpop hits that high, maybe that's why my truck doesnt like the higher hp tunes
A plugged air filter will keep boost and EBP low. That sounds weird, but we've all heard a vacuum cleaner speed way up when the hose gets plugged. That's the air being evacuated from the compressor wheel, offering less resistance, and it takes less push to make the wheel spin faster. It's difficult to tell the difference from exhaust leak and plugged air filter with data alone - so a visual inspection for soot under the hood or a dirty air filter is needed.
A boost leak is a whole 'nother matter: The turbo is blowing far more air volume, so the EBP skyrockets and the boost... well.. doesn't.
A healthy truck with a stock turbo will show about 18 PSI boost (MAP 32-33 PSI at sea level), with EBP hovering above it with 37-43 PSI. The spread gets bigger with tunes: I've seen many stock turbos with 53 PSI EBP and 39 to 44 PSI MAP, but this can be deceiving because the EBP sensor maxes out at about 53 PSI. The back pressure can be higher and we have no way of knowing how much.
The graph was from Stock-ish Stinky with 240K miles on the HPOP. I was having an issue with ICP nosedives on tunes, and the T500 was recommended to fix the ICP. While the T500 was a huge improvement with the chipped truck, it didn't solve all my woes - the problem ended up being elsewhere.
You would have more back pressure with the red line off and plugged than on the wastegate plugged in. Your wording is a little confusing but I dont think it works like that
A plugged air filter will keep boost and EBP low. That sounds weird, but we've all heard a vacuum cleaner speed way up when the hose gets plugged. That's the air being evacuated from the compressor wheel, offering less resistance, and it takes less push to make the wheel spin faster. It's difficult to tell the difference from exhaust leak and plugged air filter with data alone - so a visual inspection for soot under the hood or a dirty air filter is needed.
A boost leak is a whole 'nother matter: The turbo is blowing far more air volume, so the EBP skyrockets and the boost... well.. doesn't.
A healthy truck with a stock turbo will show about 18 PSI boost (MAP 32-33 PSI at sea level), with EBP hovering above it with 37-43 PSI. The spread gets bigger with tunes: I've seen many stock turbos with 53 PSI EBP and 39 to 44 PSI MAP, but this can be deceiving because the EBP sensor maxes out at about 53 PSI. The back pressure can be higher and we have no way of knowing how much.
^^Nuggets o' Gold^^
I've been seeing relationships and corridors of values indicating performance or lack thereof, but haven't zeroed in on the exact details. This post helps a LOT.
Saved, filed, in my reference library Thanks, Rich
Yes, I found that post by tugly super useful too. Thanks!!!
Now, just to add to my confusion about my own truck. I finally saw 16 PSI of boost today and managed to capture a log for it. I have not changed anything. The EBP seems less noisy here too. I don't have any way to explain why.
Should I expect to see max boost pulling a hill with trailer (~8,000 lbs) at about 60 MPH? The MAX I can find in my logs is 14.32 PSI at 2898 RPM with MAP=28.5 and EBP 35.5.
Yes, I found that post by tugly super useful too. Thanks!!!
Now, just to add to my confusion about my own truck. I finally saw 16 PSI of boost today and managed to capture a log for it. I have not changed anything. The EBP seems less noisy here too. I don't have any way to explain why.
Should I expect to see max boost pulling a hill with trailer (~8,000 lbs) at about 60 MPH? The MAX I can find in my logs is 14.32 PSI at 2898 RPM with MAP=28.5 and EBP 35.5.
I would think that the 3rd gear run would require WAY more CFM than the 2nd gear run. Does this in any way help with my clogged air filter theory?
The air filter visibly looks fine. I guess I could weight it, but I don't know what a new one weighs....
I did have to roll off the throttle on hills quite a few times due to EGTs getting to 1250....
In the graph the first part where the ebp jumps up, the boost actually goes down a tiny bit and it happens again in the graph towards the end.
This seems like what Tugly was saying about the boost leaks, because the map drops 1 psi or so and ebp increases 5 psi. But I'm no expert with these data logs yet so I'm sure if im right someone will chime in soon
Have you replaced your intake boots or at least cleaned them?
if your getting 16 psi on a stock setup then you are darn close to max, within 5% of max.
The problem I see is that you should not be seeing 1250 EGT's in a stock setup.
Could you take a pic of your air filter? Also see if Kiwi 2 or Dash Pro will allow you to monitor your Manifold air temps.
The data is a bit confusing and hard to read & see the colors. Any way to increase the line fonts?
.............Should I expect to see max boost pulling a hill with trailer (~8,000 lbs) at about 60 MPH? The MAX I can find in my logs is 14.32 PSI at 2898 RPM with MAP=28.5 and EBP 35.5.....
Not in OD, but close in 3rd. The issue again in my mind is your EGT's. With those higher rpm's I would expect to see more around the 1100 degree range.
The turbo pic looks good, looks clean and no oil or dirt build up
Thanks, Rich 
