02 tahoe 5.3 summit 450hp, RPM level 5 4l60e.. tuning advice

[02hotrod]

hey guys.. this is my first post. here it goes!
so I installed some new parts on my 02 Tahoe 4wd, ill list below. the tune I got from my local tuner is far from my exceptional. I've gone 4 rounds back and forth with data logging and tunes that they send back. It's like my concerns are not being addressed.

for example:
running rich - tuner verified that
idle is too low
stalling while going from drive to reverse, not all the time.
stalling while turning into parking spots etc. again not all the time.
feels low on power at lower rpm
while at 3/4 throttle from a dig feels slugging, after 3k rpm its very noticeable that the tune feels more spicy. its like flipping a switch. something isn't right.
the trans shifting is probably the most frustrating thing.
1st to 2nd- is fine, but really hard at WOT
2nd to 3rd- depending on throttle goes in and out of lock up it feels like it's searching. also at WOT it'll also do this
3rd to 4th- hangs in 3rd a lot longer than it should, for example I'll let off throttle in 3rd it stays in 3rd and will eventually shift to 4th. 4th also searches like 3rd.
normal highway speeds normal driving goes in and out of lock up
if i want to pass someone on the highway feels like I need to give it lot more throttle than I should for it it downshift
my tow /haul button was supposed to have a more aggressive shifting table.
could someone look over my tune and data logs. Am I being over critical? The drivability just isn't there and I've lost all conference in my tuners abilities.

thanks in advance for any advice or edits.

engine spec:
* Horsepower: 450+
* Torque: 420+
* Block: Seasoned OE LM7/5.3L iron
* Bore/stroke: 3.800-3.820 in. x 3.622 in.
* Year range: 1999-2007
* Displacement: 323 C.I.D.
* Crankshaft: OEM GM 3.622 in. stroke internally balanced 24-tooth reluctor wheel
* Connecting Rods: OE GM forged powder metal 6.093 in.
* Pistons: Hypereutectic flat top
* Piston rings: Moly
* Compression ratio: 10:1 compression
* Camshaft: Summit Racing Pro LS Roller
* Camshaft specifications: Lift- 550/550, Duration @.050- 222/232
* Camshaft bearings: Installed and clocked to OEM position
* Cylinder heads: #799 OE aluminum 64cc 2.00 in./1.55 in. valves
* Freeze plugs: Brass installed and sealed
* Rocker arms: OE powdered metal 1.7 ratio
* Oil Galley plugs: Installed and sealed

stock flex fuel injectors
stock fuel system
stock intake

long tube headers 3" collectors
high flow cats
3" x-pipe - deleted y-pipe
dual 3" all the way back
magna flow mufflers


cam specs:
part number sum-8713r1
Basic Operating RPM Range: 2,500-6,500
Intake Duration at 050 inch Lift: 222
Exhaust Duration at 050 inch Lift: 232
Duration at 050 inch Lift: 222 int./232 exh.
Advertised Intake Duration: 274
Advertised Exhaust Duration: 284
Advertised Duration: 274 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.550 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.550 in.
Valve Lift with Factory Rocker Arm Ratio: 0.550 int./0.550 exh.
Lobe Separation (degrees): 112

trans specs:
Media Blast Transmission Case
RPM Level V 3-4 Clutch Pack
RPM Reinforced Sunshell with Collar and Bearing
Heavy Duty Double Caged 29 Element Sprag
4L65E Low Roller Clutch
Billet 4th Gear Servo
Transgo HD-2 Shift Kit
Corvette Servo
Wide 2-4 Band
Updated Aluminum Accumulator Piston
Bushing Kit
New Shift Solenoids
New GM Valve Body Spacer Plate
GM Filter
RPM Spec Clutch and Band Clearances
Seal & Gasket Kit
RPM Sleeved Input Drum
Billet Over-Run Piston
GM 5 Pinion Planetary Gearsets ? Front and Rear
Dyno-Tested Before Shipping
2200 stall

3.73 gears






2002_Tahoe_222-232 LTH 91 oct 3.73 2200 stall.hptdata log after tune #4.hpl

[Hondaeater]

Welcome to the forum.
You should have less than 30 channels logging at time. The Gen3 especially the P01 do not have the bandwidth for all these channels. Unfortunately we must work on parts of the tune at a time not all at once.
What size TB do you have.
DBC use IAC to set the idle not the BRA table. Your IAC count is too high at idle. IAC count should be 30-40 at idle.

Nice build and details.
You need larger steps between the TCC apply and release and they should be progressive.
Minimum throttle release has been changed.
Shift lock should be disabled.

The stall is most likely because it is set to go into idle routine at 11 mph. Your Cracker air adder is disabled at that point and no longer contributes air, and the IAC count is too high so it does not have enough left to open and save the stall. Get the IAC count in line and set the Throttle cracker enable/ disable back to stock.

Use these channels if you want to help guide you in setting the IAC.

[HATEHPTUNERS]

You have the tire size listed in your tune as 29.77".. Is that correct? The reason I ask is because the shift issues you are describing usually come with tires that are larger than 31".. At least that has been my personal experience. Usually with tires under 30" you don't see many shift issues, unless someone has been jacking with the trans tables.

[Alvin]

The biggest problem I see is the IAC counts are very high. This means the valve is as opened as it possibly can and still cannot let in enough air for a good idle. You need to either enlarge the hole already in the throttle body (my choice) or open the blade position but make sure the TPS % reads zero. I have instructions how to setup a throttle body I can link if I need to.

It doesn't look rich by the log. The fuel trims were really close.

The trans stuff just takes time/experience to get right.

You should trim down your channels.. Logging too much will slow things down.

[02hotrod]

hondaeater..like the name!

thanks for the help. so I reconfigured my channels.
my TB is stock, I have the tall truck intake. not sure of the actual size of the TB.
I'll data log this morning and post this afternoon with the new channels.
thanks again

[02hotrod]

thanks for the reply. honestly I haven't looked at that. I have 20" rims I'll have to check the overall diameter to verify if that is correct.

[02hotrod]

thanks for the reply, I did cut down on the channel list pre hondaeater, Ill be posting a new data log this afternoon. I would be interested in those instructions for the TB hole resize.
thanks again

[Alvin]

here you go

https://www.pcmofnc.com/2021/03/05/i...throttle-body/

[02hotrod]

hey man.
so i was able to data log this morning with the new channels.data log 1 idle tuning 10-10-22.hpl

[02hotrod]

my tire size is 31.9. I'll have to change that in the tune. thanks for catching that.

[HATEHPTUNERS]

You are UNDER GEARED. You can try and tune around it... But it's just a crutch. If I were in your shoes... I'd swap to a higher numeric gear ratio, and a higher stall converter NOW. If you make those changes, it will make the combination feel more "alive"... Also, your BRAF #'s are showing signs of needed improvement. I've run your latest log using an IDLE DESIRED AIRFLOW graph and it shows your Base Running Airflow #'s in your tune are significantly lower than what the engine actually needs. This is why your log shows your LTIT + STIT requesting as much as +8 lb/hr at parts of your log. Russ K Idle config can be found easily. It will help you dial in your BRAF. After that, your IDLE COUNTS will need to be logged and possibly adjusted. DON'T make any changes to blade position until AFTER the Russ K IDLE CONFIG is done and the BRAF is dialed in, and then do another log. Depending on if you need to LOWER, or RAISE, the IAC counts will determine your approach. Closing the throttle blade INCREASES idle counts. Opening the blade REDUCES idle counts. Sometimes drilling the hole in the blade larger is necessary but that should be a last resort.

Also, your trans shift scheduling tables show that your NORMAL tables are actually HIGHER than your PERFORMANCE tables in the upper TPS% ranges. In the lower ranges, your normal tables are lower.. In short, your NORMAL table in the upper TPS range IS going to hold the gears longer until you hit those specific MPH #'s.. With 3.73's and 32" tall tires.. Your current set up is going to make for a lagging upshift, and poor performance, and slow acceleration, and feel like it has less power than it truly is capable of making. Re-gear it, re-stall it, and life will be drastically improved. I'd recommend at minimum 2800RPM stall speed, and 4.33's. At 70 MPH with 4.33 gears, and your current tires will give you 2234RPM.. That is more than livable on the freeway and will make the truck get up and move in the lower RPM range.

You are set in your tune to a blended tune-MAF & VE-until 2000RPM. Then MAF only above 2000RPM due to Dynamic air disable.. Were you aware of that? Was it set that way on purpose? What were the considerations for MAF only above 2000RPM? Under full throttle, or at, or above, 13,500HZ the MAF is going to revert back to the VE table.. But you have DYNAMIC air disabled at 2000.... I'm not sure what's going to happen under full throttle when, or if, the engine exceeds the 13500HZ MAF point.. Maybe someone smarter than me can explain what will happen in that circumstance. I'd be interested to know if that was done on purpose.. and if so... what was the reason. I'm trying to understand what was the goal in setting up the tune that way. Not saying it's wrong-because I don't know that it is... I'm just trying to educate myself on what I'm seeing.

[02hotrod]

You are UNDER GEARED. You can try and tune around it... But it's just a crutch. If I were in your shoes... I'd swap to a higher numeric gear ratio, and a higher stall converter NOW. If you make those changes, it will make the combination feel more "alive"... Also, your BRAF #'s are showing signs of needed improvement. I've run your latest log using an IDLE DESIRED AIRFLOW graph and it shows your Base Running Airflow #'s in your tune are significantly lower than what the engine actually needs. This is why your log shows your LTIT + STIT requesting as much as +8 lb/hr at parts of your log. Russ K Idle config can be found easily. It will help you dial in your BRAF. After that, your IDLE COUNTS will need to be logged and possibly adjusted. DON'T make any changes to blade position until AFTER the Russ K IDLE CONFIG is done and the BRAF is dialed in, and then do another log. Depending on if you need to LOWER, or RAISE, the IAC counts will determine your approach. Closing the throttle blade INCREASES idle counts. Opening the blade REDUCES idle counts. Sometimes drilling the hole in the blade larger is necessary but that should be a last resort.

Also, your trans shift scheduling tables show that your NORMAL tables are actually HIGHER than your PERFORMANCE tables in the upper TPS% ranges. In the lower ranges, your normal tables are lower.. In short, your NORMAL table in the upper TPS range IS going to hold the gears longer until you hit those specific MPH #'s.. With 3.73's and 32" tall tires.. Your current set up is going to make for a lagging upshift, and poor performance, and slow acceleration, and feel like it has less power than it truly is capable of making. Re-gear it, re-stall it, and life will be drastically improved. I'd recommend at minimum 2800RPM stall speed, and 4.33's. At 70 MPH with 4.33 gears, and your current tires will give you 2234RPM.. That is more than livable on the freeway and will make the truck get up and move in the lower RPM range.

You are set in your tune to a blended tune-MAF & VE-until 2000RPM. Then MAF only above 2000RPM due to Dynamic air disable.. Were you aware of that? Was it set that way on purpose? What were the considerations for MAF only above 2000RPM? Under full throttle, or at, or above, 13,500HZ the MAF is going to revert back to the VE table.. But you have DYNAMIC air disabled at 2000.... I'm not sure what's going to happen under full throttle when, or if, the engine exceeds the 13500HZ MAF point.. Maybe someone smarter than me can explain what will happen in that circumstance. I'd be interested to know if that was done on purpose.. and if so... what was the reason. I'm trying to understand what was the goal in setting up the tune that way. Not saying it's wrong-because I don't know that it is... I'm just trying to educate myself on what I'm seeing.

OK! that is a lot of info that you just bestowed upon me, it'll take me some time to figure all that out being that I'm a novice to tuning. I'm willing to learn!. In the short term it sounds like I need to re-gear my truck, I was thinking about 4.56 already. it's NOT my daily so I'm ok with the higher RPM's at higher speeds also it'll hardly drive on the highway. as far as the last part goes the tuner set all that. I guess my next question is, will any of what you explained hurt my engine or trans? or its just going to be annoying until I change the gearing, stall and tune? I really do appreciate your input and taking time out of your day to help me with this.

[Fast4.7]

You are UNDER GEARED. You can try and tune around it... But it's just a crutch. If I were in your shoes... I'd swap to a higher numeric gear ratio, and a higher stall converter NOW. If you make those changes, it will make the combination feel more "alive"... Also, your BRAF #'s are showing signs of needed improvement. I've run your latest log using an IDLE DESIRED AIRFLOW graph and it shows your Base Running Airflow #'s in your tune are significantly lower than what the engine actually needs. This is why your log shows your LTIT + STIT requesting as much as +8 lb/hr at parts of your log. Russ K Idle config can be found easily. It will help you dial in your BRAF. After that, your IDLE COUNTS will need to be logged and possibly adjusted. DON'T make any changes to blade position until AFTER the Russ K IDLE CONFIG is done and the BRAF is dialed in, and then do another log. Depending on if you need to LOWER, or RAISE, the IAC counts will determine your approach. Closing the throttle blade INCREASES idle counts. Opening the blade REDUCES idle counts. Sometimes drilling the hole in the blade larger is necessary but that should be a last resort.

Also, your trans shift scheduling tables show that your NORMAL tables are actually HIGHER than your PERFORMANCE tables in the upper TPS% ranges. In the lower ranges, your normal tables are lower.. In short, your NORMAL table in the upper TPS range IS going to hold the gears longer until you hit those specific MPH #'s.. With 3.73's and 32" tall tires.. Your current set up is going to make for a lagging upshift, and poor performance, and slow acceleration, and feel like it has less power than it truly is capable of making. Re-gear it, re-stall it, and life will be drastically improved. I'd recommend at minimum 2800RPM stall speed, and 4.33's. At 70 MPH with 4.33 gears, and your current tires will give you 2234RPM.. That is more than livable on the freeway and will make the truck get up and move in the lower RPM range.

You are set in your tune to a blended tune-MAF & VE-until 2000RPM. Then MAF only above 2000RPM due to Dynamic air disable.. Were you aware of that? Was it set that way on purpose? What were the considerations for MAF only above 2000RPM? Under full throttle, or at, or above, 13,500HZ the MAF is going to revert back to the VE table.. But you have DYNAMIC air disabled at 2000.... I'm not sure what's going to happen under full throttle when, or if, the engine exceeds the 13500HZ MAF point.. Maybe someone smarter than me can explain what will happen in that circumstance. I'd be interested to know if that was done on purpose.. and if so... what was the reason. I'm trying to understand what was the goal in setting up the tune that way. Not saying it's wrong-because I don't know that it is... I'm just trying to educate myself on what I'm seeing.

Tune is set that way because someone was too lazy to dial in the VE table all the way.

That 5.3L will not even come close to hitting 13,500 hz.

[HATEHPTUNERS]

Thanks Fast! I know that most factory tunes have the Dynamic Air disable set at 4000 so I was just wondering why someone would have lowered his down to 2000. I'm learning it's very common for "TOONERS" to just do the MAF tuning, and leave the VE table alone as apparently it just takes more time.. Since they did not tune the VE table, or the upper RPM ranges of the VE table.. What happens under full throttle? Does the MAF just run the show? I thought, and I could be wrong here... that under full throttle the PCM resorted back to fueling the engine from the VE table.. If the TOONER did not tune the VE table, and the data in the cells is wrong, is there not a possibility to burn up the engine by running it too lean, or just not making the best power because of running it too rich? What do TOONERS do when they just do a MAF tune, do they go into the VE table and just globally add 20% or some other random # to keep it from leaning out under full throttle?

[Fast4.7]

Thanks Fast! I know that most factory tunes have the Dynamic Air disable set at 4000 so I was just wondering why someone would have lowered his down to 2000. I'm learning it's very common for "TOONERS" to just do the MAF tuning, and leave the VE table alone as apparently it just takes more time.. Since they did not tune the VE table, or the upper RPM ranges of the VE table.. What happens under full throttle? Does the MAF just run the show? I thought, and I could be wrong here... that under full throttle the PCM resorted back to fueling the engine from the VE table.. If the TOONER did not tune the VE table, and the data in the cells is wrong, is there not a possibility to burn up the engine by running it too lean, or just not making the best power because of running it too rich? What do TOONERS do when they just do a MAF tune, do they go into the VE table and just globally add 20% or some other random # to keep it from leaning out under full throttle?

Whatever you set the Dynamic air flow transition RPM to is where it goes to full MAF. When tuning the MAF you set it to like 400 rpm so that it never uses the VE tables. That being said I only tune my VE tables to ~4,000 rpm except for WOT. WOT I will tune the VEs to fuel kill. I will tune the VEs up to 4,000 rpm across the rest of the MAP range. I shoot a little high at say 5,000 rpm and 20KPA. My logic there is if I am over 4,000 rpm and low KPA it is because I just lifted off the throttle and its transitioning to DFCO anyway. As long as it is not lean on a throttle lift until the DFCO activates the short terms will pull the slight extra fuel. I generally transfer fully to the MAF by 3,000 rpm because it usually has a more accurate signal than the MAP based VE table does. The MAF is measuring airflow, the MAP is merely a pre-programmed approximation.

I have my Express vans 383 transfering fully to MAF fueling as soon as the MAF signal is clean at about 1,600 rpm. That is a personal preference thing based on how consistent the fueling is on MAF only using a LS3 MAF in a 100mm MAF housing with a 6:1 flow straightner. With the old stock Vortec 3.5" MAF I had it set for 3,000 rpm. Once again based off where the signal cleaned up.

[HATEHPTUNERS]

Thanks kindly for your personal take on the information. I find it very difficult to tune the VE tables anywhere above 3K or so because I'm doing road testing.. By 3K things are getting busy pretty quickly, even when you limit it to 2nd gear. Nice to know I can transition to MAF at 3K and still be okay. You mention the MAF signal "cleaning up".. Is there a way to log that to see where the signal begins to provide a more accurate, or stable, signal? Is it just something you watch for on a basic log such as following the hz, or lb/hr reading from the MAF? I guess as long as I keep the transition point above where the MAF usually starts to provide a stable signal, I'll be okay. Maybe that's why the factory sets them so high at 4K.. they know by that point there is enough airflow across the MAF sensor that it should be providing an accurate/stable signal by then.

[Fast4.7]

Thanks kindly for your personal take on the information. I find it very difficult to tune the VE tables anywhere above 3K or so because I'm doing road testing.. By 3K things are getting busy pretty quickly, even when you limit it to 2nd gear. Nice to know I can transition to MAF at 3K and still be okay. You mention the MAF signal "cleaning up".. Is there a way to log that to see where the signal begins to provide a more accurate, or stable, signal? Is it just something you watch for on a basic log such as following the hz, or lb/hr reading from the MAF? I guess as long as I keep the transition point above where the MAF usually starts to provide a stable signal, I'll be okay. Maybe that's why the factory sets them so high at 4K.. they know by that point there is enough airflow across the MAF sensor that it should be providing an accurate/stable signal by then.

You pretty much nailed it. You can watch the frequency in the datalog. Some setups with alot of reversion or a descreened MAF will dance around with 300+ HZ swings which can be a 3-4 MAF cell drift. The engine will also let you know what it likes if you go to MAF only too soon. The air/fuel ratio will have nasty swings as well as the short term fuel trims will swing wildly above and below Zero, sometimes as much as 6-8%. With the VE and MAF tables properly tuned the switch should not even be noticeable. I have noticed the switch point on stock engines on the dyno before as well. On a stock setup that I was datalogging as it was dyno'd had a large spike in pulsewidth right at 4,000 rpm and the corresponding AFR dip on the dyno's wideband.

[Tunercharged]

I like the responsiveness of MAF only tuning in open loop. I just set the maf cells for the lambda I want using my wide band. I only have one maf table, 32 cells I think, and that is plenty precision for me. PE on top adding when needed and crank the WOT timing, easy.idle rpm might have to be a little high but no more so than VE tables running the show I should think. Closed loop is where wild cam can spoil the idle tuning easiness.