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[Gremlin85]

Engine Diag, under airflow should be all the settings. That the place you changed things?.

Yes. But I just noticed that I didn't change the desired boost (psi) in overboost error to read 165 kPh. Do I need to do anything to the overboost hyst?

It feels like I'm learning to do this all over again

[Terminator2]

I've been running your somewhat tamer cam tables for a while now, the ones you posted above really killed my cruise MPG for a DD. I have to get my Boost & DAL's in order before I start on anything else.

Killed MPG and response IMHO. Exhaust cam opens too soon to allow for peak cylinder pressure to be reached. Needs more retard at 40,50,60,70% loads than you do at 120%+ loads Car pulls more vac on the guage and airloads at cruise remaine the same but car suffers from a feeling of some turbo lag as you roll into the throttle as well as a 10-15% drop in fuel mileage.

[gmtech16450yz]

Killed MPG and response IMHO. Exhaust cam opens too soon to allow for peak cylinder pressure to be reached. Needs more retard at 40,50,60,70% loads than you do at 120%+ loads Car pulls more vac on the guage and airloads at cruise remaine the same but car suffers from a feeling of some turbo lag as you roll into the throttle as well as a 10-15% drop in fuel mileage.

Sounds like you're not compensating for the cam timing changes with other tables. You can't make big changes like this without making other things work with it. The stock turbo needs no help from cam timing to spool, actually it's the opposite, this turbo has a tendency to spool so fast all it does is spike then drop. The secret is a smoother build of boost, not an immediate 0 to 30psi. Believe me, I can show you logs with this cam timing that spools hella fast straight to 30psi, the cam timing does not kill boost spool.

The best analogy I've had for this is the theory that retarding the ignition timing will also spool the turbo faster because of increased exhaust temps. To me this is an example of engineers thinking too much. OK, so increased exhaust temps do help turbos spool faster, but think about what you're doing when you retard the ignition timing to the point of making a difference in exhaust temps... YOU LOOSE TONS OF POWER! I would never retard ign timing to try to help a turbo spool faster, all that would do is make the off boost part of the power worse, which in turn would make a peaky, hard hitting midrange with no low end. Which, btw, most people would think is stronger by the seat of the pants or butt dyno "feel" because of a weak low end and then a hard hitting surge of power.

The other thing to remember about the big cam timing retard at freeway cruise, it's only there for two reasons. Emissions and fuel mileage. Do you know why mileage goes up on stock cam timing? Because retarding the cam timing reduces pumping losses. In an oversimplified way of explaining this, if you have a motor that makes 150hp at freeway cruise rpm and throttle, and the car only needs 50hp to maintain that 65mph, you're loosing efficiency. If you make that motor only put out 50hp because that's all it needs, you increase efficiency. Highest mileage is reached at the lowest rpm AND the highest throttle opening at any given load. If you actually made a motor that only put out 50hp so it would be at full throttle at freeway cruise, it would get far better mileage than the 150hp motor. Only problem would be if you wanted to accelerate! (No wait, Toyota already made one, it's call a Prius!) Retarding cam timing in the midrange will almost always result in power loss on most any motor, turbo or not.

[Terminator2]

Sounds like you're not compensating for the cam timing changes with other tables. You can't make big changes like this without making other things work with it. The stock turbo needs no help from cam timing to spool, actually it's the opposite, this turbo has a tendency to spool so fast all it does is spike then drop. The secret is a smoother build of boost, not an immediate 0 to 30psi. Believe me, I can show you logs with this cam timing that spools hella fast straight to 30psi, the cam timing does not kill boost spool.

The best analogy I've had for this is the theory that retarding the ignition timing will also spool the turbo faster because of increased exhaust temps. To me this is an example of engineers thinking too much. OK, so increased exhaust temps do help turbos spool faster, but think about what you're doing when you retard the ignition timing to the point of making a difference in exhaust temps... YOU LOOSE TONS OF POWER! I would never retard ign timing to try to help a turbo spool faster, all that would do is make the off boost part of the power worse, which in turn would make a peaky, hard hitting midrange with no low end. Which, btw, most people would think is stronger by the seat of the pants or butt dyno "feel" because of a weak low end and then a hard hitting surge of power.

The other thing to remember about the big cam timing retard at freeway cruise, it's only there for two reasons. Emissions and fuel mileage. Do you know why mileage goes up on stock cam timing? Because retarding the cam timing reduces pumping losses. In an oversimplified way of explaining this, if you have a motor that makes 150hp at freeway cruise rpm and throttle, and the car only needs 50hp to maintain that 65mph, you're loosing efficiency. If you make that motor only put out 50hp because that's all it needs, you increase efficiency. Highest mileage is reached at the lowest rpm AND the highest throttle opening at any given load. If you actually made a motor that only put out 50hp so it would be at full throttle at freeway cruise, it would get far better mileage than the 150hp motor. Only problem would be if you wanted to accelerate! (No wait, Toyota already made one, it's call a Prius!) Retarding cam timing in the midrange will almost always result in power loss on most any motor, turbo or not.

We did not have access to those injection angle tables before so yes it was missing half the puzzle but I still think you have the midrange intake and exhaust cams advanced a little too far as far as overall drivability and efficiency are concerned (with the stock intection angles). Tom shares my opinion, but I have not tested the advanced injection timing with advanced cam tables yet. I will do so today to see what happens.

[BackyardTurbo_FTW]

Watch your Rail Pressure when switching to Fuel Mass mode instead of Normal..

[gmtech16450yz]

Saw some of the stuff on not getting full boost duty cycle... All I can say is it's possible, there's obviously something going on between your guy's tunes and mine, I wonder if it's a difference in the Kappa vs. Delta OS's? I'm working on getting my boost back under control where I had it before, which means I'm almost stock on the new boost tables down low because of this happening... OUCH! Almost 30psi in 5th gear at 3100rpm. Don't try this on stock pistons. You can see I'm trying to drop duty cycle down from the 95% it started at but still not enough here. Full throttle in 5th gear is not something I would normally do, but I like to make sure boost levels are safe and low enough even under conditions like this.

[acesneights]

Probably a dumb question, but I looked yesterday for it and couldnt find it. What PID do you use for the boost dc?

[Iam Broke]

Boost Desired Duty Cycle in the scanner is what I use.

[T-Man]

John,

I think you're right about the skewing of the MAF Freq and it messing with torque calculations. I set my MAF Freq back to stock and (I plan to incorporate the global offset within the MAF Correction table) the car is MUCH more responsive than it was before, I.E touchy touchy... Prior to this, I had my DAL/MAL setup perfectly and the car was very docile and predictably smooth. This leads me to believe that you're correct.

Will report back later after I've had a chance to go WOT. Thanks for the tips John and thanks for the late chime in agreement Tom!

[Iam Broke]

T - If you correct in either the MAF freq or the MAF correction it'll skew the same air load readings. T2 convinced me of that last year. Try to adjust your Inj Constant instead sometime to get the trims in line. From what Nick posted the % change works the same way. I haven't tried it yet though.

I'm still seeking the 95% Boost Desired DC I had up top on the 'other' tune. I lost 1.5 psi at 6k and .3 sec off my 60-100 times.

[T-Man]

T - If you correct in either the MAF freq or the MAF correction it'll skew the same air load readings. T2 convinced me of that last year. Try to adjust your Inj Constant instead sometime to get the trims in line. From what Nick posted the % change works the same way. I haven't tried it yet though.

I'm still seeking the 95% Boost Desired DC I had up top on the 'other' tune. I lost 1.5 psi at 6k and .3 sec off my 60-100 times.

So, some slight changes to both tables, to fine tune fueling, would be acceptable. However, large offset changes will skew airload/torque calculations all to hell.

Is that correct?

Thanks Tom.

[Iam Broke]

I loaded Nick's DC Correction with 300 DAL's and boost was way down on mine in the midrange, it did see 95% DC for 1 sec at 6300 rpm though. Much slower overall.

I could watch the ramps in the graph though as it crossed each RPM threshold.

Here's what I logged on Nick's table in a 3rd gear pull...

3k - 15.5 psi
4k - 19.5 psi
5k - 21.6 psi
5.5k - 22.2 psi
6k - 20 psi
6.4k 18.3 psi

Stepping it up to try tomorrow. Just seems wrong somehow to have to do it this way.

Gotta be another table or twelve hidden yet.

[Iam Broke]

So, some slight changes to both tables, to fine tune fueling, would be acceptable. However, large offset changes will skew airload/torque calculations all to hell.

Is that correct?

Thanks Tom.

That's the way I see it. I believe you could zero out your LTFT's with the injector constant and then use MAF correction for the STFT's.

Remember that any % change in injector constant isn't passed on to the BCM for the DIC MPG's. Increasing the Inj constant made my displayed MPG's go up to 130% on E85 with the 'other' layer loaded.

[Leafy]

That's the way I see it. I believe you could zero out your LTFT's with the injector constant and then use MAF correction for the STFT's.

you could actually make a histogram that would do this for you. lets see. yes the value in the equation would be, [current injector constant]*[SENS.114]. Then you'd just log that into one cell and paste special add to the injector constant and that should work (unless your injector constant is more than one cell, then you would recreate the table). If I was to do this I would get the car tuned perfectly with normal gas and then put in a tank of e85 and run this histogram.

[T-Man]

you could actually make a histogram that would do this for you. lets see. yes the value in the equation would be, [current injector constant]*[SENS.114]. Then you'd just log that into one cell and paste special add to the injector constant and that should work (unless your injector constant is more than one cell, then you would recreate the table). If I was to do this I would get the car tuned perfectly with normal gas and then put in a tank of e85 and run this histogram.

Makes perfect sense Leafy. Thanks man

[sundevil07]

Just getting around to messing with this, i borrowed byt's duty cycle correction and dals and modified them to my liking. Seeing 94.5 wg dc at 6500, brought the boost on a little sooner and harder as well. Pull is very linear compared to my last tables. Tomorrow begins my quest into e with Drewbroo helping a TON!

[BackyardTurbo_FTW]

Tom, send me your file if you don't mind and Ill adjust the boost like mine to make sure its the same. Ive tuned several cars now with the new tables and haven't had an issue.


Im having major issues with the Fuel Pressure table, like it doesn't do what's commanded.. And not being able to log FRP still is also a major issue IMO. We need that.. We can log commanded but not actual. My table is set to ramp from 1700psi to 2300 at 6k. The car will hold 2200 flat then ramp to 2300. When I log commanded MPa, it shows it commanding exactly what it's doing and NOT my table that I have set. Either it's labeled wrong or we're missing something else that's not letting me adjust the pressure properly. I even tried to adjust the Positive Ramp Table with no change at all.

[Iam Broke]

Thanks Nick, I will send the one I tried last night for your review.

I wrote one with higher midrange settings but never loaded it yet to try.

Not enough time in the day...

[Terminator2]

Still cannot get above stock WG DC on my car or another car I am tuning on E-85 not sure what is going on but it seems like certain OS do not react the same I have an 09 GMPP stage 1 file in my car.

[BackyardTurbo_FTW]

Try using a regular 09 file with the Map values changed to GMS1 values and see if it controls boost for you (new tables are nice )