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 FAQ: How to tune the PCM? (Series II SC)

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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 02, 2014 1:25 pm

Abaddon wrote:
That doesn't sound right. Dyno time is dyno time. What they tune during the session is what you're paying for. I see no reason to buy anything else from them. I haven't been pleased at all with them lately. Last time I emailed them asking what the difference was between the Lucas and Bosch Injectors, all I got was "Bosch is a better Injector". Yeah thanks idiots. That REALLY helps me out. They're customer service is shit IMO.

wow..  dunce 

They are telling me that it will cost more in dyno time to get me to a base tune than it would to load the 1.0 PCM.

So I ask them, well, since I am paying for dyno time and for parts and install for the cam, can't you just load the 1.0 for me and we will tune from there?

They said I have to pay for it before we start tuning..... come on..
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matt270avian
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 02, 2014 1:48 pm

You're just paying for their "expertise" on the 3800 platform... The only thing I would even consider letting them do is the cam after reading all of this. There's probably plenty of good dyno shops around you that would do it for way less than what ZZP wants.
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 02, 2014 1:50 pm

Kinda need to get the thing tuned before I drive it home, tho
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 02, 2014 8:08 pm

Does anyone have the ZZP 1.0 PCM .hpt file or want to split the cost with me?

Curious to open it up and compare it to mine..
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptySun Apr 20, 2014 12:54 pm

Please help me understand why my KR drops as my RPM and TPS increase. There is only 1 KR spike after I am WOT. Any ideas why? Shouldnt KR increase as RPMs increase?

Does it have to do with the LTFT #?
FAQ: How to tune the PCM? (Series II SC) - Page 8 Captur10
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptySun Apr 20, 2014 3:36 pm

KR is applied immediately when knock is heard. It doesn't immediately go away as soon as the knock is suppressed though, it decays slowly. So you should always see it slope down after you get your KR peak(s). What you have is some reoccurring KR. It's hearing knock, retarding timing, then once the timing starts to come back up as KR decays, it's hearing more knock again and so you get that stair-stepping kinda stuff in your graph. Definitely got some knock there to work on.
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptySun Apr 20, 2014 5:04 pm

turtleman wrote:
KR is applied immediately when knock is heard. It doesn't immediately go away as soon as the knock is suppressed though, it decays slowly. So you should always see it slope down after you get your KR peak(s). What you have is some reoccurring KR. It's hearing knock, retarding timing, then once the timing starts to come back up as KR decays, it's hearing more knock again and so you get that stair-stepping kinda stuff in your graph. Definitely got some knock there to work on.

But look at the timing graph. it doesnt go back up, it keeps going down as KR decays.


Do I have a lean condition? Is my LTFT a clue?
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyMon Apr 21, 2014 10:03 pm

Do I have this right? When it comes to tuning, is the name of the game to advance the hot spark timing table as high as you can without causing knock? Up each cell to it's max but keep KR at 0?

Is that what this is all about?

I changed my hot octane spark table by upping timing in each cell by 2%. I FELT an instant power increase across the band. Do I just keep pushing my timing until I see knock and then adjust as needed to keep timing high and KR zilch?


here's my timing table now. I am getting minimal KR with this tune but a definite increase in power and MPGs. I am shocked. I dont know how else to explain my results. I feel the power and I see my gas tank staying fuller.

FAQ: How to tune the PCM? (Series II SC) - Page 8 Captur11
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 23, 2014 10:19 am

You don't want to necessarily go as high as possible. There are theoretical 'optimal' timing settings based on RPM and cylinder pressure to have the explosion happen at just the right time. That's really where you want it to be.

For emissions reasons GM makes their "acceleration pump" action a bit lean. I can't remember the setting, but it's basically fuel enrichment for throttle movement. When you snap the throttle open a blip of extra fuel is added to counter the rush of air. That is off a bit giving you the KR spike on throttle movement. One thing you can easily change is the rate at which KR ramps down. (again, I forget the name of the setting but it's in various tuning guides).

There's a book by Greg Banish - http://www.amazon.com/Engine-Management-Advanced-Greg-Banish/dp/1932494421 I highly recommend it as he covers all of those factors. He doesn't get specific to any particular tuning software. It's worth the $15.
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyWed Apr 23, 2014 9:46 pm

Thanks, Deek. Do you still have that upload URL where I can look through the files and stuff?
Is that a sticky somewhere?

How do I know what is optimum for my setup?


Looking at this scan, does it seem like the shifting of gears caused a false positive KR response?
Why else would KR spike when RPMs drop? Did the transmission trigger the KR microphones?
FAQ: How to tune the PCM? (Series II SC) - Page 8 Captur12
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 8:33 am

A couple things I see with that scan:
You are pig rich. AFR cmd is 11 -> 10 that's way too much fuel.

O2 is weird - a steady 12.6? No change at all? Do you have a rear O2 sim? You might be reading the wrong O2 sensor.

Shifting can absolutely cause KR and it's generally okay to ignore. Based on both KR spikes I see, you should shorten the recovery rate.

Your STFT is 0 the entire time. That's not right either.

What kind of scanner is this? Are you using a WB O2 sensor?

Also - PM sent.
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 8:43 am

First thing to realize about KR: it is not RPM dependent. It's easy to assume knock is created as RPM increases, but it's actually not the case (I think it's assumed because boost rises with RPM). Actually though, increasing RPM decreases load, helping the engine breath, which lowers knock.

Knock is more dependent on octane, boost, timing, A/F mix, and most of all, load.

Load, in simple terms, is when the engine/drivetrain is using the most torque. In our cars this occurs at low RPM. Our tall gearing has a lot to do with it. For given amounts of boost, A/F, and timing, you'll always see more KR at very low RPM under high loads. When you shift up a gear at WOT you increase load abruptly, lowering RPM. This is what I see happening in your 2nd graph.

Another example would be in OD climbing a hill. If you're not tuned for it, it'll be KR city. Drop to 3rd gear on the same hill and what happens? RPM increases, load decreases, and KR goes away.

One more example: pulling a trailer, the added weight is an extra "load". A car tuned for no KR without the trailer will see quite a bit more when pulling. RPM has nothing to do with it.

Knock is also timing dependent, so at any given instance if KR, retarding spark timing will help. This is why the PCM counters knock with KR - it's the quickest and surest way to make the adjustment electronically. Look at your graphs. After the KR steps, you can see timing is instantly retarded. This is partly why KR starts to roll off.

The other reason KR rolls off in the graph is because you are increasing RPM, which decreases load. The blips that don't follow upshifts are probably the result of A/F or timing issues. These can be tuned for correction.

Timing and A/F ratio can be tuned to a point, but there is an optimal value for each. Once you've gotten to that value it makes sense to stay there. Example, an A/F ratio of ~11.5:1 is ideal at WOT in my set-up. I can keep dumping fuel at it, but a 9:1 ratio isn't gaining anything power-wise, and it wastes fuel. Same with timing. There is a point where optimal timing produces the perfect amount of torque at a particular RPM. Beyond that point the efficiency is lost. No reason to push any further.

Your KR issue is the main reason I eventually started to support breathing mods and shift tuning (including minimizing TCC-lockup), rather than focusing on high torque and increasing boost with smaller pulleys. Why increase load and KR when you can maximize power through RPM and air flow, automatically addressing the knock issue. This is also why I don't have an IC - don't need one.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 8:57 am

deekster_caddy wrote:
A couple things I see with that scan:
You are pig rich. AFR cmd is 11 -> 10 that's way too much fuel.

O2 is weird - a steady 12.6? No change at all? Do you have a rear O2 sim? You might be reading the wrong O2 sensor.

Shifting can absolutely cause KR and it's generally okay to ignore. Based on both KR spikes I see, you should shorten the recovery rate.

Your STFT is 0 the entire time. That's not right either.

What kind of scanner is this? Are you using a WB O2 sensor?

Also - PM sent.

Yeah,,,,, dont mind that WB O2. I dont have one installed and it just reads 12.6 the whole time.

I will take it off for the next scan I post.
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 12:36 pm

charlieRobinson wrote:

deekster_caddy wrote:
A couple things I see with that scan:
You are pig rich. AFR cmd is 11 -> 10 that's way too much fuel.

O2 is weird - a steady 12.6? No change at all? Do you have a rear O2 sim? You might be reading the wrong O2 sensor.

Shifting can absolutely cause KR and it's generally okay to ignore. Based on both KR spikes I see, you should shorten the recovery rate.

Your STFT is 0 the entire time. That's not right either.

What kind of scanner is this? Are you using a WB O2 sensor?

Also - PM sent.


Yeah,,,,, dont mind that WB O2. I dont have one installed and it just reads 12.6 the whole time.

I will take it off for the next scan I post.

Oh - just saw the 'real' O2 sensor. That's not much better. Seems like you are way too rich. Kind of normal for a starter tune though, so no worries there.

Those KR blips are small and go away quickly, plus are right at the shift, so I'm not majorly concerned with them. Just the KR sensor doing it's job. Did you read through the tuning guides?
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 1:50 pm

Not yet,but thanks for the reminder, Derek. I will try to review them tonight.

They should make more sense to me know that I have some EXP.

Also, do you guys use the 'scan thingy' tool?

I used it last night for my MAF tuning and timing tables and the results it spit out looked legit.

I uploaded the new tune before my commute to work. I am going to scan it as soon as I can then get back to the tweaking.


SO GLAD I MADE THE DIVE AND GOT THE HPT PRO. THIS IS SO REWARDING AND SO MUCH FUN.
INSTANT POWER AND MPG GAINS AND I DONT EVEN KNOW WHAT IM DOING.

I will be ordering a wideband O2 sensor this weekend.
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 3:30 pm

Now that I have HPT I don't use the scan thingy anymore. Once the tune is close I prefer to make changes by hand. It's typically only 3 or 4 cells I want to make changes to at a time on the big tables, once the main tuning work is done.

I'm psyched because HPT just gave me beta access to work on the Volt! wink
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charlieRobinson
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 8:21 pm

deekster_caddy wrote:
Now that I have HPT I don't use the scan thingy anymore. Once the tune is close I prefer to make changes by hand. It's typically only 3 or 4 cells I want to make changes to at a time on the big tables, once the main tuning work is done.

I'm psyched because HPT just gave me beta access to work on the Volt! wink



That's awesome. Did you have to spend credits to unlock the Volt or was it a beta free trial deal?


Is this another example of transmission noise causing KR? Would increasing shift pressure prevent this?

I havent even started tuning the transmission yet.
FAQ: How to tune the PCM? (Series II SC) - Page 8 Captur13
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyThu Apr 24, 2014 11:28 pm

No, it's not the transmission. It's the increased load after the shift, on top of a lean A/F mix (O2 value is low, and LTFT is +).

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 8:49 am

Does IFR determine LTFT? It's pulse width right? so lower values = more fueling?
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 10:40 am

IFR is one way, but setting IFR is better used for skewing rates to the middle cylinders, which run hotter. The right way to tune fueling is to modify MAF table. When you go WOT (open loop), your O2 stops sending feedback to the PCM, so it reads directly from the MAF table for fueling.

What you want to do is move your scan preview slider to the area where you have KR. Note the MAFF Hz values. Find those values in your MAF table and increase by 1%. Run again and scan. See if the knock goes away. If no improvement, you may consider cutting timing at the RPM where the KR is occurring.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 11:29 am

I understand that the MAF table is used when we are at WOT but what determines LTFT when are at closed loop and just cruising?

That's what im trying to tune now.

I changed my IFR back to stock after INCREASING the values slightly and scanned this morning and now my LTFT is 0 to -5. So I think I am on the right track.

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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 11:58 am

Sorry, I was thinking of injector skew perfect re: middle cylinders. 3 & 4 at 100, 1,2,5,6 at 96.

For IFR, mine start at 8% over stock (0 kPa), then 7% (10 kPa), 6% (20 kPa), and 4% for all the others above that. This is the way DHP programmed the 1.5 BIN, and I never changed it.

deekster can confirm, but my understanding is fuel trims start with the MAF table and then use input from O2 when at idle/cruise. So if your LTFT is off, it means O2 is telling the PCM to correct by x amount. Log the LTFT at specific MAFF values, then adjust the MAF table at those values according to how your rich or lean your LTFT indicates. For example, if LTFT is +2.3 at 4000 Hz MAFF, bump up the fueling in the table by 1% at 4000 Hz and do another run. You'll never get it perfect, but after about 50 tunes, my LTFTs are mostly between 0 and -2.3. Don't worry about decel numbers - they are more difficult to tune.

Be careful when you reset fuel trims, LFTF will set back to zero at start. Give it a few miles before you make any conclusions.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 12:56 pm

Fuel trims are based off your MAF Hz and O2 primarily. LTFT shows you the average for that particular point in the system (MAF table, VE table, MAP sensor, ECT, etc all taken into account and more). It's actually several tables working together, but the MAF and current O2 have the biggest impact. LTFT shows you the average correction needed. STFT shows you the immediate corrections (with LTFT already being accounted for).

There is always a little load spike during a shift. Don't fret over it. It's not "Noise" - it's actual KR from a massive change in load. Increasing shift pressure and shortening shift times will help improve your shift, but may not have any change on the shift KR. It may actually make that a little worse (it's a big load and shifting faster may make that load even bigger). Shorten the KR recovery time a little and don't fret over it. It's not a big deal.
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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptyFri Apr 25, 2014 1:46 pm

deekster wrote:
There is always a little load spike during a shift.


Just to add, raising the upshift points will lessen the severity of the load change a little (make sure your upper valvetrain is up for it). Also programming downshifts to happen sooner will keep you out of low RPM/high load territory, also makes throttle more responsive.

Just optimizing the PCM's downshifting is a great way to tune out KR, seriously.

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FAQ: How to tune the PCM? (Series II SC) - Page 8 Empty
PostSubject: Re: FAQ: How to tune the PCM? (Series II SC)   FAQ: How to tune the PCM? (Series II SC) - Page 8 EmptySat Apr 26, 2014 11:29 am

Is the AFR commanded a value that can be set in HPT or is it a compilation of different sets of data and dynamically generated?

If there is a table for it to set it, I cant find it.


How we lookin now? I am much happier with the LTFT. I think i will move on to transmission soon and see if i can eliminate the rest of the KR.
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