Chevy Impala Forums - Reply to Topic
PCM and Technical Tuning PCM and High end tuning discussion here.

Thread: KR logging on 3.6L LFX engines Reply to Thread
Title:
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

Register Now



In order to be able to post messages on the Chevy Impala Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
10-20-2015 11:44 AM
jtrosky FYI - here is a link to the exact settings you need to enable true tap shift (this is from the Camaro forums, but I believe that this will work on the Impala too):

2ls with Sport Mode and manual mode - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com

Basically, the Camaro LS comes stock just like the Impala - with the ERS is manual mode. Apparently, these settings will make the Camaro LS act just like the Camaro LT, which allows for true tap shift from the factory.

It's funny, all of the "pro" tuners were telling the Camaro folks that it couldn't be done - and then some guy just tried setting the trans setting to the same values as the Camaro LT and sure enough, it worked!

EDIT: By the way, this should also let us setup a "sport" mode, where you can make the shifts quicker/firmer and re-adjust shift points. Basically, when you go into "M"anual mode, you'd be in "Sport" mode (which would still shift automatically, but use the "sportier" shifts) - unless/until you use one of the paddle shifters - then you'd switch into true "tap-up/tap-down" mode (no automatic shifts). If you wanted to get back into automatic "Sport" mode, you'd hold the upshift paddle for 2-4 seconds and it would return you to "Sport" mode... Of course, while in "D"rive, shifting would operate normally. Pretty cool setup! Will have to try it myself soon....
10-17-2015 05:52 PM
jtrosky Haven't enabled it yet... I do know the correct settings to enable it, but just haven't done it yet. I'm not sure if you can set it up to work when in drive or not, but I think you can - have to re-visit the info on HPTuners...
10-17-2015 04:35 PM
F16vipers How do you like the true tap shifting? I've been thinking about enabling it on mine. Does it only function in Low or do you have to paddle shift in D also?
10-17-2015 06:09 AM
jtrosky Of course, one thing that should be mentioned in regards to Torque Pro vs. HPTuners monitoring - using Torque Pro is a LOT less "intrusive" since you can use it on a phone or small tablet without wires (uses bluetooth).

The HPTuner scanner application requires a Windows device and uses a thick cable between the OBD-II port and the Windows device (I use an Asus T100 tablet/keyboard dock combo, which works really well). I usually just put the Asus on the passenger seat so that I *can* review it in real-time if desired - but you could also just put it on the back seat floor or something and review the data later. Honestly, being able to review the data later, in the comfort of your home, for example, is the best way to use the data anyway. But it's nice having the ability to monitor real-time in certain situations as well.

Really, they are two different tools that can both be used in different situations. One "compliments" the other. :-) But for *true* data logging and analysis, HPTuners is the much better tool. For quick data review or code scanning, Torque Pro makes more sense.
10-17-2015 05:04 AM
jtrosky
Quote:
Originally Posted by retiredpauly View Post
Edit
Do I understand you that you can watch this happen real time as your driving ?
Yes, you can watch it in real time (along with TONS of other data) or, probably even more useful, is that you can "replay" the data logs at your leisure. And not just play the logs back at normal speed - you can play it back at multiple different speeds and even more useful, examine the data frame-by-frame. And you can also define "histograms", which allow you to easily identify peaks and problem areas without having to search through the logs. The HPTuners Scanner application really is a game-changer. I always thought that Torque Pro was awesome - and it is cool - but, the HPTuner scanner app makes Torque Pro seem like a toy in both the amount of data that you can review and the ways that you can review it.


Quote:
Originally Posted by bignick2015 View Post
These 3.6 cars (the 9th gen more so than the 8th) seem to be tuned to stay in a high gear as much as possible for economy, so tuning the transmission might help elminate some KR (by providing a quicker kickdown at less throttle %).
I completely agree. In fact, I've altered the transmission shifting tables quite a bit to do exactly what you talk about. I don't go into 5th and 6th gear as quickly as stock and I also release the TCC lockup clutch and/or downshift with much less throttle input now. Really does make a significant difference in the overall responsiveness of the car - it just reacts to throttle input so much better now.

Still messing with my tune - I just can't quit - I *love* logging data and trying new things. Now that I've got the timing and trans shifting refined just like I like it, I'm now going to start messing with:

- Reducing torque management slightly during upshifts - basically, I'm going to start by removing 10% of the upshift torque management during low RPM, low torque shifts and removing 5% of the upshift torque management during mid RPM, mid torque shifts. Plan on leaving torque management intact for high RPM, high torque upshifts.
- Going to try disabling "Torque Shaping" - supposedly, this will make the throttle feel a lot more like a throttle-cable driven throttle - more "direct" feel between pedal and throttle.
- Going to try disabling "Discrete Shift Torque" - basically, when this is enabled, the transmission will use a pre-defined pressure value for shifts for a given torque range (low, mid, high) - supposedly, this allows the transmission to learn the pressures quicker and easier. Some people like leaving this enabled and others like disabling it. Curious to see what difference it makes. In my mind, I'd want the computer to use the actual shift torque values instead of just "estimating" it like it does when Discrete Shift Torque is enabled.
- Going to enable true tap-shifting instead of the range-select version of tap-shifting that the Impala uses by default. Basically, this will allow me to select the gear that I'm in instead of just allowing me to select the highest gear that it will use. May be useful in the winter, so that I can start off in 2nd or even 3rd gear, for example.

Lots of cool, fun stuff you can do!!!
08-10-2015 06:00 PM
jtrosky Yeah, I spent a lot of time review logs and used the IAT table and IAT multiplier table to get a good mix of where and when to removing timing based on temps. Someone on the HPTuners board recommended it. What's nice is that there is an "IAT Advance" PID so you can actually see exactly when and how much timing it's removing when reviewing logs (so it definitely does work).

Still need to dial it in a little more as I drive in some more temperatures, but so far it's seemed to help quite a bit (between it and modifying the high/low spark tables themselves in a few places - especially the 1200 RPM row!

I never in a million years planned on getting into car tuning, but it's been an extremely rewarding experience. I'm a computer guy by trade and I've always loved exploring every option when dealing with computer stuff (first thing I do when using a new device or new app is explore all of the options and mess with them), so tuning these computerized cars is a dream come true - TONS of options!!! :-)

Sent from AutoGuide.com Free App
08-10-2015 05:27 PM
F16vipers
Quote:
Originally Posted by jtrosky View Post
Yeah, I probably shouldn't worry about it since it does it from the factory with the factory tune, but since I don't need to squeeze every last drop of power from the car, I decided to attack the problem a little. It's amazing how much the KR can be reduced/elminated by just removing a degree or two of timing here and there. Now, the most I ever see (so far) is 4 degrees - and even that is rare - it's usually 2 or less now. I've also started to tune the IAT (Intake Air Temp) spark modifier tables so that the hot weather (IAT's over 95F) don't affect it so much. Surprisingly, the IAT tables weren't used at all from the factory (or with the Overkill tune).

I've also settled on a compromise between the stock and Overkill tunes regarding how fast it restores timing when it does detect knock - the stock tune restores timing VERY slowly and the Overkill tune restores it VERY quickly. I decided to go with a "middle of the road" value so that it restores timing relatively quickly, but not as quickly as the Overkill tune. I've been doing a LOT of logging with HPTuners and I've learned so much about how these cars work - I mean I've really learned a LOT! :-) Very cool stuff...

I've found that the car defaults to the High Octane table and only moves towards the Low Octane table if and when it experiences knock. Since I saw KR so often with 93, I can only imagine how much timing gets pulled with 87 octane! There is no doubt in my mind that this car runs better with 93 octane fuel.

Sent from AutoGuide.com Free App
I remember about a year ago we both were a little hesitant to jump into the tuning world but I'm sure glad I did. Good call using the IAT table...I honestly never messed with that because I figured the car wouldn't use it since the stock values are all 0...might have to give that a try because the temperature seems to be the biggest culprit for KR for me.
08-10-2015 01:41 PM
bignick2015 Retiredpauly, I figured it probably WAS a typo, but just wanted to add a warning, just in case someone found a "race fuel" additive of some type that contained it and figured it would be OK or beneficial to use the stuff.
08-10-2015 12:04 PM
retiredpauly My mistake in my first posting I made. I did in fact say methanol.
The subsequent posting I referred to it as ethanol.
Maybe spell check got me or I didn't proof read it.
I dunno
But I meant ethanol.
08-10-2015 07:54 AM
bignick2015
Quote:
Originally Posted by TSS View Post
No, but I watch the KR closely on the Lincoln. No issues, but I watch it. As you know, KR is the worst under lugging conditions (ie. struggling in a high gear when you should really be in a lower gear).
These 3.6 cars (the 9th gen more so than the 8th) seem to be tuned to stay in a high gear as much as possible for economy, so tuning the transmission might help elminate some KR (by providing a quicker kickdown at less throttle %).

Quote:
Originally Posted by retiredpauly View Post
What's the ethanol content of your 93 gas.
Y'all have different requirements there than we'all do.
Our "premium" gas (shell) has no methanol.
Just wondering if it's the same for you. ?
No gasoline you buy (unless you're buying racing fuel) should have methanol! That stuff will eat your fuel system even at low concentrations, and should be considered a contaminant, not an additive. I'm assuming you meant ethanol (all pumps around here are labelled 10% or "up to" 10% ethanol).
08-09-2015 10:08 PM
jtrosky Yeah, I probably shouldn't worry about it since it does it from the factory with the factory tune, but since I don't need to squeeze every last drop of power from the car, I decided to attack the problem a little. It's amazing how much the KR can be reduced/elminated by just removing a degree or two of timing here and there. Now, the most I ever see (so far) is 4 degrees - and even that is rare - it's usually 2 or less now. I've also started to tune the IAT (Intake Air Temp) spark modifier tables so that the hot weather (IAT's over 95F) don't affect it so much. Surprisingly, the IAT tables weren't used at all from the factory (or with the Overkill tune).

I've also settled on a compromise between the stock and Overkill tunes regarding how fast it restores timing when it does detect knock - the stock tune restores timing VERY slowly and the Overkill tune restores it VERY quickly. I decided to go with a "middle of the road" value so that it restores timing relatively quickly, but not as quickly as the Overkill tune. I've been doing a LOT of logging with HPTuners and I've learned so much about how these cars work - I mean I've really learned a LOT! :-) Very cool stuff...

I've found that the car defaults to the High Octane table and only moves towards the Low Octane table if and when it experiences knock. Since I saw KR so often with 93, I can only imagine how much timing gets pulled with 87 octane! There is no doubt in my mind that this car runs better with 93 octane fuel.

Sent from AutoGuide.com Free App
08-09-2015 09:29 PM
F16vipers
Quote:
Originally Posted by jtrosky View Post
I was just wondering if anyone has logged the amount of KR (Knock Retard) that they are getting on their 3.6L LFX engines. I'm always reading how these engines are tuned from the factory with lots of KR, so I recently started paying more attention to the KR levels in my HPTuners logs. I was kinda startled by the amount of KR that I seen in the logs! I've seen up to 9 degrees of KR, but that was rare - what really caught my attention was how *often* there was KR (not really the number of degrees of KR).

I always run 93 octane gas, so I really wasn't expecting to see KR so often. The hotter it is outside, the worse he KR seems to be. Also, certain RPMs seem to consistently produce KR - for example, between 1200 and 1300 RPM at light throttle, KR was particularly bad. I seem to be at 1200-1300 RPM a lot while just cruising at a constant speed and I would see KR until I either let off of gas a little or applied a little more gas.

Just yesterday, I removed a degree or two of timing at certain places in my high octane table, paying special attention to the 1200-1300 RPM range and sure enough, it seemed to help significantly, so I don't believe that this was false knock or anything like that. Currently, my timing tables are from the Overkill 91 octane tune, but KR was even worse with the stock tune (mainly because the stock tune is a LOT more cautious about removing KR, so you generally see it more often as it slowly restores the timing - the Overkill tune restores timing MUCH faster than the stock tune when it encounters knock).

Anyway, I was just curious if anyone else has logged and/or monitored their KR levels in the 3.6L LFX engine - and what their results were. Not just at WOT (where I rarely see KR), but at part-throttle as well.

Sent from AutoGuide.com Free App
Yea this car is designed to advance and retard timing at will. I also started running 93...I mostly worry about WOT...as long as no KR shows up there I don't worry too much about it. Temperature seems to have a lot to do with it. Once it gets below 70 degrees the KR starts to fade. As long as it's less than 10 degrees the computer can account for it and it's not doing any harm to the motor. If it's pulling timing at WOT you're losing power and nobody wants that!

I still have people argue with me about this car being able to take advantage of 93 Octane without a tune...and it sure can...the tables are already there and slowly but surely the computer will advance the timing if no knock is detected. Another thing I did was to decrease the rate and degrees the computer pulls timing...sometimes it will pull 4 or 5 degrees when it really only needs 1 or 1.5. Just be careful with those tables...because you still want it to retard timing when needed.
08-09-2015 09:23 PM
F16vipers
Quote:
Originally Posted by KG2014 View Post
The 87 octane I've been running is 12% ethanol. They do have ethanol free premium at one location about 15 miles north of me for $.40 more then the ethanol premium. How much does ethanol effect the gas?


Sent from AutoGuide.com Free App
93 Octane is 93 octane regardless of the amount of ethanol...ethanol has a lower BTU rating than gasoline and basically lowers the 'potency' of gasoline. It can reduce gas mileage and power...not a lot but noticeable.
08-06-2015 05:18 PM
retiredpauly I was thinking more of phase separation in the storage tanks at the dealer.
I pick up about 7% in mpg (L/100 km) if I use ethanol free fuel ( premium)
As to whether it knocks more or less I dunno.

Edit
Do I understand you that you can watch this happen real time as your driving ?
08-06-2015 03:16 PM
KG2014 The 87 octane I've been running is 12% ethanol. They do have ethanol free premium at one location about 15 miles north of me for $.40 more then the ethanol premium. How much does ethanol effect the gas?


Sent from AutoGuide.com Free App
This thread has more than 15 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome