4l60e 2008 Silverado Standard Cab 4.8l Truck Norris NSR Stock Torque Converter

[GHuggins]

Last 4.8 I did with this cam ran and pulled better than a stock 6.2 non tuned if that helps you any... I haven't looked at your logs, but the tune looks a little low on timing in places where it needs it in the lower rpms. Just verify your mechanicals are indeed good with whatever shop verified things - ask them how they did the verification's. Honestly if it was off on the cam it should set a cam crank correlation, but will require some drive time to set the code if not out that bad.

Then when you say won't rip the tires off - power braking or just stomping from a stop?

[TheGizmo]

Last 4.8 I did with this cam ran and pulled better than a stock 6.2 non tuned if that helps you any... I haven't looked at your logs, but the tune looks a little low on timing in places where it needs it in the lower rpms. Just verify your mechanicals are indeed good with whatever shop verified things - ask them how they did the verification's. Honestly if it was off on the cam it should set a cam crank correlation, but will require some drive time to set the code if not out that bad.

Then when you say won't rip the tires off - power braking or just stomping from a stop?

Stomping from a stop will not even try to brake traction. It will try and power brake, but I didn't want to waste the rubber when my gut tells me otherwise. No codes set after CAM gear replaced, I can't say how many drive cycles have happened on a single tune to set a code for crank / cam correlation, but I know at least two have had two cold starts between tunes. The owner of truck is shop owners Son so I am not sure if they have reset codes recently while looking into other issues. I guess it's time pull the tech II out.

Interesting I did tell the owner before I tuned that cam should run on stock tune. The first day after cam was installed the truck did run but idle was cranky. I had two base line tune preps that should have run decently and that's when I found out the wrong CAM gear was installed. After correct CAM gear was installed the stock tune was in ECM and the idle and overall seemed worse than with the incorrect. After pulling my hair out on erratic surge idle after IAT was over 107'ish I found vacuum line not plugged in. This made an immediate difference, and I found #3 plug wire boot leaking to exhaust manifold randomly. I swapped wire 1 & 3 since 1 has less manifold surrounding it and my insulation leaks were gone and could not find anymore. After this the road test started and the engine idle seemed too high in D but continued on with test. The second observation was short coast to stop the engine would attempt to stall so a natural instinct from the pre EFI days or trying to get repeatability from known customer complaint was to prep for recovery. A normal coast to stop was no issues thought. Everything seemed decent throughout the rest of the first road test except first gear just seemed to be weak in part to full throttle. I did not see any knock jump out and trims were +20 on LT so I knew I had some tuning to work with and much was expected.

I am thinking after I have confirmed new pugs and wires, I should put the OE tune back in and get some logs. The OE tune was not ever flashed once the VAC and plug wire was resolved to get a base after CAM to compare. My original tune prep was not even flashed after the leak was resolved. Thats an error on my end wanting to get results knowing nothing was adding up with cold idle to normal operating temperatures on third part day. I have too much time vested in this one right now to just say this is all I can do when my gut tells me otherwise even if owner seems to think this is an improvement over stock cam.

[GHuggins]

It won't run on a "stock" tune just right until it does some self learning. A lot of people change things for these cams they don't need to. Usually they just require using stock or near stock rpm settings and then do the usual "big cam" mods to go with it. By that - as I know it's kind of contradictory - I mean leave rpm settings near stock, massage adaptive settings, raise min air slightly, tweak idle torque model as torque is almost always too high, tweak throttle follower to get torque commanded the same as delivered, raise idle timing up around 21, dial in injection timing (pretty important with this one), shift idle adaptive spark over a couple of cells, then dial in VVE, MAF and timing. Problem is people make the "usual" cam mods and then idle is all over the place and everything else then of course if you have exhaust or anything address all of that. It may just wind up being a plug that's bad - one cylinder makes a big difference...

This is a log from a 5.3 I'm doing right now - min air is too high pulling timing down and still needs air and timing tweaked along with some hot start surging issues addressed after I iron out the min air just for a reference. BUT you can see the tires start to spin on the first 3-2 downshift where rpms jump straight up and traction pulls timing. This log doesn't have any dead stop take offs, so not sure if will help much there. Timing should be close to what the 4.8 will take.

I had a 5.3 do like what your describing, but it was a cam with too much lift killing port velocity. Wouldn't get out of it's own way until 2000rpms. The truck norris isn't like that and you may just have a weak unmaintained engine.....

[TheGizmo]

Thanks for this information and pointers along with the log. I just went back through the tune before I started tweaking on adaptive settings before the vac leak was found. I don't recall if I adjusted out the throttle follower and I did not re-visit the injection timing. I will install stock and work it back out from that. Late Friday afternoon I will be back at the truck. I hope he has new plugs and wires installed.

On a side note, I will more than likely install this same CAM in my 2013 5.3 with 6L trans. This all depends on if I pull the engine and work the bottom half.

[TheGizmo]

Sorry for the long delay for an update. Not much has changed or has been done. Still no plugs installed or WBO2 sensor. I did put stock back in truck and see if it would run since this was not done after the leak was found. The truck actually started as and idled as suggested. I did not try and see if surge idle would learn but installed 1st tune and idle was much better. Owner installed a throttle body spacer in hopes this would help the bottom rpm range but this did not fix his problem.

Watching misfire monitoring and trim action and a major imbalance of trim between both banks I am certain spark is the major culprit. I have the wideband kitted and ready to install and this should take place between Monday and Tuesday along with new plugs and wires. As a side note as a test before the WB gets installed, I put a MAF tune for a stage 2 cam I was working on and disabled CL operation and misfires went down a lot and richness by smell seemed to be mild (No Cats) compared to CL trimming. After plugs and wires are installed I will verify NB against WB.

Other note, I am pretty sure I am not dealing with any transmission issues after looking at factory trans tune and modified tunes everything seems to happen correctly as commanded after slight calibrations. This thread is probably in the wrong topic at this point, but maybe this information will help someone with similar situation.

[TheGizmo]

Any thoughts on this except the obvious that I may be missing? Plugs and wires have not been replaced yet but did install WB on bank 1 side then swapped to bank 2 side just to make sure the NB sensors are working correctly. I am seeing an imbalance between left and right bank and had a thought maybe the NB sensors are causing a false rich condition, but I am not seeing this being the case but the plugs causing a misfire.

I did not try and tune for open loop due to the imbalance that I am pretty sure is spark issues or fuel delivery. Plugs should be done tomorrow.

WB Bank 1
23-01-30 16-15-57.hpl

WB Bank 2
23-01-30 17-11-59.hpl

[GHuggins]

Advance injection timing about 25 degrees and retest. Usually bank to bank like this are injectors or corresponding restrictions or weaker than the rest cylinders. Inj timing can help things burn more equally by getting the fuel atomized and burnt more uni-formally.

[eighty6gt]

Greg, how much are you changing what value to move it by 25 degrees? Is this a global change? IE: parameter 3120, or:
injection boundary normal table.png

[GHuggins]

Eighty6gt. Yours is a gen3. I can't remember on those - think .01 was 5 or 6 degrees or something like that. Try lowering the whole table .05 at a time until fuel trims are the most negative and you have good throttle snap response.

[TheGizmo]

Thanks, wish I would have read this earlier, but I must have been on the right track because this is what I tweaked on mainly today after plugs and wires were installed. Plugs and wires made a huge difference and the trims started to balance out better. I then tweaked on Injector timing but I retarded it. OEM was originally 110 normal op temp and in the previous logs I posted it was 105. Today I left it at 101. Up and down from this point seemed to plateau. I did not feel comfortable tweaking lower and did not seem necessary to go higher than stock. I guess my thought process is backwards on injector time calibration, or I am just thanking backwards on the injector being advanced from time. I will try going in other direction Wednesday or Thursday.

On the GEN3 is the number just an engineering number without a known scale or is it in RAD? Just curious if it actually correlates with somethings that can be useful to do a quick conversion, or a table for someone to use in the future.

GEN4 ECM - 13337.png

23-01-31 16-57-54.hpl

[blindsquirrel]

And MAP is still upper 80s at idle? Is that normal for that cam (107* LSA)? Do the brakes still work?

[TheGizmo]

Idle is 648ish. Brakes .,.,, it does not try and jump into traffic,,, much, the tune still needs therapy and to your point at low idle that is high never thought about, I guess will need a sign that says do not track wet mud on brake pedal, truck may or may not jump into traffic. Mud seems to help out with the rear wheel breaking traction was all excited for a moment and realized no changes were made and a clay tire trail following me. The last cam I did was 111* and had less overlap. Just got hammered on GEN5 but not the issues I am having with his truck. This is my first with close overlap with stock lift.

This is the current tune. I have a lot to clean up from trials. The owner swapped gas, and I think he said he added a bottle of alcohol to the tank. Along with heavy weight Oil for tractor.

Rooster_OK_01312023_TEST2.hpt

23-01-31 16-46-52.hpl

[blindsquirrel]

Back when I was young and stupid I had a SBC with a 266/278 (at .050!) 108*LSA solid roller, with vacuum brakes. It would stop just fine but you only got one shot at it. Had to be driven like a big truck with air brakes going down a hill, if you got on that brake pedal you'd better stay on it until you're stopped.

[GHuggins]

Maps usually around low to mid 70's on these. There are two different truck norris cams. One low lift and one high lift. As long as the braf is right, it shouldn't have an issue stopping.

You can go both ways on inj timing. Just find the one that better suites you.

[blindsquirrel]

Idling at 88kPa the brake booster would be awfully easy to deplete if you aren't careful with the pedal. 750-800 RPM and more idle timing would help a bunch. Think I remember seeing it at 13*?

88kPa is 12kPa below atmo, or 3.5in-hg, less if you aren't at sea level...

[TheGizmo]

Looking back through some logs tracking the 13* is coming from idle overspeed adder. I have not made any adjustments today and I did not adjust the idle after the plug change yesterday. The idle at higher speed seemed to have less of surge but this was too much on the stock stall at a red light. After reading Gregs reply about the idle should be close to stock on this CAM I backed up and loaded stock because I didn't check stock after vacuum leak was repaired.

This is the low lift no springs required model and the springs did not get replaced. I had some though earlier in the tune process that I may be fighting weak springs. Specs: 212/22X, .498/.498, 107 LSA

Going to sleep on it and maybe I'll wake up with that Euricka moment. I am having a hard time thinking this may be something in this tune. I will be logging injector timing results in for +/- 25* maybe this will be that breaking moment so I can tune the idle smoother.

Think adjusting a few percent on Idle, Airflow, effctive area, percent max will help anything, I tried this before the vac leak due to seem to have to do this on large cams.

50 miles off the coast so baro offsets are very low. I actually commute to the coast daily and see very similar. After you mention the map it brought back some carb days where I experienced this. Only time I can ever say I had this issue was major leak.

I did check the manifolds with thermal imager yesterday. All 8 cylinder's seem to have even exhaust temp and I am not finding a cold spot from a vacuum leak.

Apologies for the mini books I am posting, trying to be detailed as possible.

[TheGizmo]

Today I did three road trials. -25* from stock injector timing, +25* from stock injector timing, and went back to the original tune or close to the original tune that was posted in the very beginning. After injector time adjustments I tired some final air and % max adjustments and I felt I might be getting close then I decided to try the best tune I had before the plugs and wires were replaced and time checked along with compression etc, etc... The owner also fixed the slight exhaust leak that was on bank 2 about where the back bed meets the cab. From feel and logs this current tune seems to be the best at the moment. Low torque still not great but the rest is not so bad.

I have data logger installed so over the next few days I will get some more data to dial in the rest a bit tighter and try and add some to the spark octane tables.

Do I use the virtual torque table to dial in the torque tables? If so, I can't seem to do this like the bug with GEN5 VVE table.

23-02-02 18-29-45.hpl

2008_48_TNCamNSR_02012023_TEST2.hpt

[GHuggins]

Yeah and HPT apparently changed their platform. I can't update beta at all as it's not compatible with a 32bit OS anymore. I'll take a look at things tomorrow or I guess later today now - if I get a chance.

[GHuggins]

Been going in circles with Paypal and trying to find out things from government all day on top of doing my other duties, so haven't been able to get around to looking at the tune until now.

750 idles not bad - better around 650 to 675 or even 700, but 750 is good for smoothing out the idle. About as high as I would go though as you'll start pushing much higher.

There's still some things you can do as far as timing and throttle. You can tweak the higher areas of the throttle tables or just lower the etc scaler. Torque management can be raised.

[TheGizmo]

Sorry I missed your last reply, I did not get a notification. It would be nice if an app was available for phones, don't get me wrong I would much rather post from a keyboard but throughout the days I think an app could be more informative of what's going on (I am sure I can do more to get better notifications). I would like to be able to pass some knowledge over to others in the future, but I am always on the go and mobile web browser view does not seem to be as good as full desktop browser.

I think I have learned more on this tune than any that I have ever done so far but still hitting roadblocks. I had a tune that was modified slightly from the one you looked at in hopes to tell something new or un-hide anything. After reviewing some standalone logs of the last posted tune of owner driving in various conditions the max torque really opened up after some adaptive learning. Seeing constant torque above 315 lb/ft and calculating engine speed with torque I am seeing theoretical in 350hp consistently (I know this is not a dyno pulled number, but it seems to be good reference to compare along with calculated torque). Other note to add is that the best pulls are early morning when we have cooler air temperature. Our area is seeing some mornings in the mid 30's but afternoon in the upper mid 70's. If you don't like our weather come back in an hour. This tells me a CAI could make a slight improvement. (Just installed S&B on my 2013 5.3l and with current tune before install seems to have a good effect, I'll be logging for an hour trip in the morning)

The downsides that I am still battling is WOT from 0 is still terrible and I see a constant 13* advance, that @blindsquirrel pointed out, at each pull, but I do not see knock pulling it down, so I am still trying to track this down. On the other side of the spectrum, I see inconsistent knock that seems to be false knock that is retarding time and killing some MBT. Very hesitant at the moment to keep adjusting spark tables due to the inconsistency of knock management. This could very well be a muffler hanger but when I do hear this, I cannot correlate it with knock graphing.

Another area is consistent stall for 2 secs between 1500 - 1600 rpms (OEM converter)

The last area that I am circling to again is the torque management. This truck does not have a t/c button and does not have a light that comes on during pre-run ignition lamp test and seems no matter what I do at ECM and TCM level torque management no changes are found or felt. Digging into this again I am finding out that this truck may not have t/c and stabletrack II. The ABS fuse has been pulled multiple times and absolutely no change.

This is tip into WOT, Timing does not match tables. I do not understand why this is 11.6* before knock pulled out 5.4*. Most of the time this is closer to 13 with no knock.
Screenshot_20230207_092549.png

Following WOT this log did very well for the most part.
Screenshot_20230207_093934.png