Finally paid to tune the LS3

I took the car to a tuning shop yesterday about 3 hours away. They have a mustang load bearing dyno whose bearings are rated at 3000HP, and they provide tuning classes for SCT & HPTuners. I'm including the tune I arrived with (113013-Postintake) and the tune I left with (TTS-DriveHome). I don't have the files/graphs yet, but to my recollection the corrected HP was around 430 and the corrected torque was around 390; he estimated it read 15% lower than a Dynojet. We didn't perform a baseline pull. The old tune was basically a tune provided by Steve Williams mail order, with spark removed where there was knock, idle timing tables meshed with main tables, and street tuned VE/MAF tables using my NGK AFX.

The tune I arrived with was OLSD because I knew my O2's were dead (replaced them a couple days before the tune but didn't change the tune) and due to blending problems between MAF/VE causing some drivability issues.

He likes to use LTFT's for part throttle (to account for varying weather conditions), and wideband only for WOT. He said STFT's reacted too quickly and there wasn't a worry about cell-to-cell cross contamination with the LTFT values. I believe he stayed in a cell until LTFT's stabilized and STFT's went to zero. We found 15-20rwtq in part throttle by adding timing. Compared to my NGK wideband VE table (which was within 2% typically on the same day I calibrated it), the LTFT's reported it being rich by up to 15%, but was much closer in the upper MAP regions. I was disappointed that the PE AFR ramped in so slowly on my PCM, and the MAP kPa above 6000 seemed to be lower than it is on the highway. The HP was basically flatlined from around 6000 to 6500, and he wouldn't run it higher because there was nothing to gain and I was manifold limited according to the kPa logged... so I don't know where the power begins to drop. I plan on taking it to a local Dynojet soon to get comparison numbers and maybe they'll run it higher.

The bucking issues I had are almost completely gone, I still have a tiny bit between 1000 and 1500RPM. But I'm having more stalling issues than I had before and I'll be working with him to get those sorted. Part throttle in 5th gear is much better, and it's so nice to not have to clutch-in early to avoid bucking.

I'l post more when I receive the data.

where is this shop at? city state??

Odessa FL, slightly north of Tampa. They are a tuning school and very rarely tune individual cars due to class scheduling conflicts.

Regarding this tune, I'm confused on the methods. I had always used a wideband to tune the entire VE & MAF tables, initially using AFR error and more recently using lambda error but I had read you could also tune part throttle using STFT's although I never tried that method. So I'm worried that the VE & MAF tables aren't as accurate as they could be.

I'm adding the most recent update calibration and default log to see if any other senior tuners with their own shop have opinions on the results. It would apear that the stalling issues are mostly rectified with this calibration on a warm start, don't know yet on a cold start.

If I understand the setup, this is a Gen III Tune running a LS3 (reluctor wheel convertor or new wheels?). The 97/98 PCMs are the slowest, least capable PCM's available and aren't near as capable todays PCM's. There might be some bucking due to processing speeds I would think.

You can tune the MAF and VE using the narrowband generated LTFT/STFT's but only in the STOICH (non-WOT) condition. Not sure why they do it that way other than they expect you to tune all the non-WOT parameters and then take to a DYNO Shop for the WOT (they install the WB) tuning?

Ed M

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Originally Posted by JimMueller

Odessa FL, slightly north of Tampa. They are a tuning school and very rarely tune individual cars due to class scheduling conflicts.

Regarding this tune, I'm confused on the methods. I had always used a wideband to tune the entire VE & MAF tables, initially using AFR error and more recently using lambda error but I had read you could also tune part throttle using STFT's although I never tried that method. So I'm worried that the VE & MAF tables aren't as accurate as they could be.

I'm adding the most recent update calibration and default log to see if any other senior tuners with their own shop have opinions on the results. It would apear that the stalling issues are mostly rectified with this calibration on a warm start, don't know yet on a cold start.

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So the reason this tune solved the stalling is you have moved the adaptive idle control up to 45 mph via the Throttle Cracker parameter. What this does is allows the idle adaptive timing control to assist in maintaining your closed throttle idle speed parameters. I have used this technique on big cam/LS1 PCM setups as well. It is probably not a recognized by some tuners, but it works. Haven't gone as high as 45 mph. I set it to parking lot speeds of say 15 mph or so. Also, do the RussK RAF tune procedure to get the idle air close to ideal.

Ed M

It's a GenIII tune on a 1998 Camaro with original OS & harness. Hand built LS3 longblock (not purchased from a vendor as a complete package) with a 24x reluctor wheel. Although I specifically have extra bungs in my collectors for widebands, they chose to use a wideband clamped to the driver exhaust, saying it would only be a 1/2 point leaner.

To be clear, all the post-dyno adjustments have come as e-mail updates from the tuner/instructor. I had the RAF table within 1 gram from about 40*F to 235*F before the instructor touched the tune. I don't understand why he changed that table, he only stated that it is now what a cam this size requires. Will changing the VE/MAF/advance tables alter how much idle airflow it wants, thus needing different values that what I arrived with?

There are also areas where the STFT & LTFT's remain far from zero, I'm waiting for his feedback on that.

Quote:

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Originally Posted by JimMueller

It's a GenIII tune on a 1998 Camaro with original OS & harness. Hand built LS3 longblock (not purchased from a vendor as a complete package) with a 24x reluctor wheel. Although I specifically have extra bungs in my collectors for widebands, they chose to use a wideband clamped to the driver exhaust, saying it would only be a 1/2 point leaner.

To be clear, all the post-dyno adjustments have come as e-mail updates from the tuner/instructor. I had the RAF table within 1 gram from about 40*F to 235*F before the instructor touched the tune. I don't understand why he changed that table, he only stated that it is now what a cam this size requires. Will changing the VE/MAF/advance tables alter how much idle airflow it wants, thus needing different values that what I arrived with?

There are also areas where the STFT & LTFT's remain far from zero, I'm waiting for his feedback on that.

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while you may have gotten some training from the tuning school...
there are things you seem to maybe not have grasped completely yet...and thats ok... you cant get everything in as short of a time as that class probably was.
you will understand why as you learn from hands on playing with it.

the RAF is a table that tells the car how much air it needs at idle...
a bigger cam needs more air to idle
and it needs more air cold than it does hot

so you can set up LTIT+STIT (Long term idle trims and short term idle trims) in the scanner and the combo of the 2 will tell you just how much air it is commanding
sometimes it takes a few passes to get it correct because it can only move as far as the ECU parameters are set up to allow.

then you often need to add a small amount to it to get it to idle as its far easier to let it have slightly too much and it has to take a small amount away rather than to not have enough and have to try to add to it.

also, your spark tables in the idle area are all over the place, and probably way too low of timing to be able to keep a rock solid idle
the Idle air will be a crutch to this if the Timing is not correct

your spark in idle areas needs to be consistent in both driving and idle tables and it needs to be a static value so the IAC and spark can do their jobs properly
a spark value that varies in the idle tables will only cause instability
it wants to see a certain amount of timing to be stable, and then gets told to use less than it needs and it cant correct fast enough.

I did not attend a class... I paid a flat rate to have the PCM calibrated by the class instructor. I arrived at 10AM, and I left around 5PM. He reviewed and made some initial changes before beginning the actual tuning. The last tune I made any changes in was the one which I had loaded when I arrived at the tuning shop (the tune named 113013-postintake1). All subsequent changes were made by the instructor.

Attached are logs from last night & this morning, no problems that I can feel or see specifically with idle stability, with the exception of it overshooting once last night and it idling a little high, and a small range of slightly high idle in the warm start log frames 650-700. There are instances of what appears to be burst knock, bucking, and large ranges where the fuel trims are off significantly.

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Originally Posted by mowton

So the reason this tune solved the stalling is you have moved the adaptive idle control up to 45 mph via the Throttle Cracker parameter. What this does is allows the idle adaptive timing control to assist in maintaining your closed throttle idle speed parameters. I have used this technique on big cam/LS1 PCM setups as well. It is probably not a recognized by some tuners, but it works. Haven't gone as high as 45 mph. I set it to parking lot speeds of say 15 mph or so. Also, do the RussK RAF tune procedure to get the idle air close to ideal.

Ed M

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Ed, disabling/raising the throttle cracker still won't allow the adaptive idle to work above 0 mph in my experience.

Russ Kemp

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Originally Posted by Russ K

Ed, disabling/raising the throttle cracker still won't allow the adaptive idle to work above 0 mph in my experience.

Russ Kemp

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Russ,

I have done this on my 2004. Here is jims log which shows 0% TPS and 22 mph and what I thought was adaptive idle timing control trying to keep the closed throttle rpms at the idle specified value. What do you think?

Attachment 43024

Ed M

I was @ a dealer show in Tampa a few years back & asked the Tuning School if there was a course available & I would take some extra time to attend. They did that, I sent them an email afterwards outlying my concerns, I've never heard back. I agree 100% with S2H comments.

Also I responded to your Mustang dyno questions in another thread, not knowing where the dyno was located. They should know how to do what you asked, if not they should have embraced the opportunity to learn something new.

As it's begun to get hot, I've been kicking on the AC right after I start the car. I've experienced multiple instances of the car stalling when slowing/stopping. Same issue as last summer, reported to this tuner before and during the visit; just didn't become a significant issue until the weather began getting hot. I tried to contact the tuner two weeks ago and he hasn't responded. I spoke with the office manager today and I inferred that because they spent so much time trying to get the dyno files off their computer to me that they've went above and beyond.... but to try to reach out to him again.

Any of you have suggestions on what to monitor (and what to change based upon those logs) to prevent the stalling without inducing other undesirable behavior? Is it as simple as raising the RAF a little bit at lower engine temps?

its all in the Idle Air tables....
probably not enough in the Base Running Airflow, and then the adaptive idle air parameters probably are not set right either.


you can also add 25~50 rpm to idle RPM, but usually its not necessary to do so.


you may also need a little bit of change to the throttle follower/cracker tables....
but I cant tell unless I'm sitting in front of it and driving it down the road or doing loaded driving on the dyno.

Hey, post your stock tune, I would like to do a compare and see what all has changed.

I added 25RPM to the In Gear AC on settings, from 46* on up, and raised the AC Offset Min/InGear, and it's stalled once so far with that change. So far I'm frustrated trying to balance an unecessarily high idle while preventing stalling under all conditions. If I have to make an emergency stop and the car stalls, there's a delay in making further emergency maneuvers. Can you tell me what PIDs to log, and how to correlate those values to changes needed in the required tables?

I've attached these calibrations:
Stock tune
Download from ecm 2-20-14: The baseline this tuning shop began with on 2/20 dyno session
Revised after dyno tune 2: The final revision provided from the tuner through e-mail on 2/22/14
Revised...Final: Current calibration

This tuner chose to begin from the calibration I arrived with, not from the stock calibration. The calibration I arrived with is a combination of settings from Frost's mail order tuning, and online ideas.

Change the Throttle Cracker enable/disable speeds back to stock. That should be your starting point.

I changed the throttle cracker enable/disable speeds back to stock. Arriving back to idle seems to be a bit less stable, no stalling yet but the weather hasn't been as hot recently. Prior, the stalling was occuring when the car had sat outside in the parking lot all day without shade, pretty hot days (mid-90s); it would start and leave the parking spot okay but if I had to clutch-in and brake hard, the RPMs would fall too fast and it would stall. As the runtime increased I couldn't duplicate the behavior.

I went to another local dyno over lunch today for a comparison. The attached Mustang dyno sheets are what I left The Tuning School (TTS) with, however I wasn't provided a printout or the files until weeks after I paid them, and only after repeated communications. They just didn't know how to get the files off the Mustang computer, it's not nearly as straight forward as doing it from a Dynojet computer. The odd AFR graph (done in the driver side tailpipe, after the cats) caused me to re-visit all the part throttle using new NBO2's and I used my existing permanent NGK AFX WBO2 in the driver side collector (I have two bungs per collector).

Today's shop was Next Level Performance (NLP), and the owner has certificates from 2008/2009 from attending Greg Banish's courses, and they even host them at their shop sometimes. Since I was last there they upgraded the dyno to the load-bearing version of the Dynojet from their prior version. If I chose dyno tune yet again at NLP, it'd be another full tune starting from the factory calibration, not just a WOT tune (they don't offer WOT-only tunes). That'd be another $550. I requested they place their AFR sensor in the same bung as my AFX, but instead they used the spare passenger side collector bung. The owner did say that Greg (Banish) has a serious difference of opinion with how TTS performs their calibrations.

So the AFR curve is now at least fairly straight, but fairly rich, and the peak numbers are way lower than expected even for a small cammed LS3. So I'm wondering if my NGK AFX sensor is out of whack? It's never been removed since it was installed, nor even a fresh air calibration done since the original install. I'm picking up a new Bosch 15401 sensor from Autozone after work and will try to resolve the potential sensor issue this weekend.

I've also attached my lambda scanning config in case I have something setup wrong. I use the reciprocal of Equivalent Ratio in formulas because Commanded EQ behaves oddly in my scanner connected to my PCM.

I am curious for your updates. As someone learning to tune, I enjoy these types of threads.