CL problem

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08-10-2009
Bluecat

2010 Camaro / blower - OL/CL problem

I've got a new camaro with a TVS1900 that I'm having trouble with getting it to kick out of closed loop. The PE enable TPS table is labled as "HOT" and is apparently just that since reguardless of what I put in the table it doesn't leave closed loop until 55%. The problem with this vehicle is that at low rpm it will make 3-4 psi of boost on as little as 30% tps. And under that much load its to lean for it to run right and bucks and hunches until you either get out of it or get on it enough to hit pe.

This is a problem I've never had before because any blower car I've ever tuned that was this new has always had a centrifical style blower or a turbo, and low rpm - low tps boost is not a problem. And obviously most older style ecm's have both a "standard" and a "hot" PE enable TPS table so get it to do what I want isn't a problem.

Also I noticed the OL lookup works a little different than in the past vs the newer computers. If I disable CL via the temp thresholds is works just like the older pcms. If the PE EQ is less than the end result of the OL EQ, it goes with the OL EQ value. This lets me use the IVT Gain table for boost enrichment. Set the pe table to 1.13 across the board and let the IVT Gain table pull it down to 1.22 or so once you get into boost. But after you enable CL, when it does finally see enough tps to kick into PE is just goes with the PE value reguarless of if the values of the OL tables is richer or not. That stinks...

So what I'm asking is what are the rest of you guys doing on newers cars with positive displacment blowers that only have a "hot" tps PE enable table?

...and to the HPT people - Is thier any plan to add the normal operation tps PE enable table to the newer calibrations?
08-10-2009
Frost

Hey Phil,

I did an PD'd e67'd TBSS that only shows the hot table but it seem to be the active choice in that cal for PE selection.

I know that Speed Inc has tuned/run a setup as you are describing, maybe PM Jim a link and see if he can shine a light on their own setup. Perhaps they are just living with it for now as well.

http://www.hptuners.com/forum/member.php?u=3130
08-10-2009
Bill@HPTuners

Quote:

Originally Posted by Bluecat

I've got a new camaro with a TVS1900 that I'm having trouble with getting it to kick out of closed loop. The PE enable TPS table is labled as "HOT" and is apparently just that since reguardless of what I put in the table it doesn't leave closed loop until 55%. The problem with this vehicle is that at low rpm it will make 3-4 psi of boost on as little as 30% tps. And under that much load its to lean for it to run right and bucks and hunches until you either get out of it or get on it enough to hit pe.

This is a problem I've never had before because any blower car I've ever tuned that was this new has always had a centrifical style blower or a turbo, and low rpm - low tps boost is not a problem. And obviously most older style ecm's have both a "standard" and a "hot" PE enable TPS table so get it to do what I want isn't a problem.

Also I noticed the OL lookup works a little different than in the past vs the newer computers. If I disable CL via the temp thresholds is works just like the older pcms. If the PE EQ is less than the end result of the OL EQ, it goes with the OL EQ value. This lets me use the IVT Gain table for boost enrichment. Set the pe table to 1.13 across the board and let the IVT Gain table pull it down to 1.22 or so once you get into boost. But after you enable CL, when it does finally see enough tps to kick into PE is just goes with the PE value reguarless of if the values of the OL tables is richer or not. That stinks...

So what I'm asking is what are the rest of you guys doing on newers cars with positive displacment blowers that only have a "hot" tps PE enable table?

...and to the HPT people - Is thier any plan to add the normal operation tps PE enable table to the newer calibrations?

AFAIK the table that is currently in there is the ONLY table in the pcm we just decided to recycle the name more than likely instead of making up a new one which saves us time.

Regarding the tps gm changed how this is read & how it works on most all gen 4 pcm'd vehicles

This is what our engineer had to say regarding this a while back

"Try with smaller values for the enable TPS. From memory it's the same weird ETC % area - idle offset % the LS2 uses. Ie. You need to set it to values like 15-20% for tradtional TPS/ETC% of 40-50%"
08-10-2009
Bluecat

Quote:

Originally Posted by Frost

Hey Phil,

I did an PD'd e67'd TBSS that only shows the hot table but it seem to be the active choice in that cal for PE selection.

I know that Speed Inc has tuned/run a setup as you are describing, maybe PM Jim a link and see if he can shine a light on their own setup. Perhaps they are just living with it for now as well.

http://www.hptuners.com/forum/member.php?u=3130

Yeah, I'd felt the same way. I was just using the hot table assuming it was the only table. I would just put the numbers in there that I would normally use on a big cam or set it up appropriate for a blower, but I don't know that I've ever actually looked at a log to see if it was doing what I told it. I never had a problem that cause me to question it. So the earlier ls2/3 stuff might use the hot table exclusively, but I know a new camaro dosen't. :banghead:
08-10-2009
Bluecat

Quote:

Originally Posted by Bill@HPTuners

AFAIK the table that is currently in there is the ONLY table in the pcm we just decided to recycle the name more than likely instead of making up a new one which saves us time.

Regarding the tps gm changed how this is read & how it works on most all gen 4 pcm'd vehicles

This is what our engineer had to say regarding this a while back

"Try with smaller values for the enable TPS. From memory it's the same weird ETC % area - idle offset % the LS2 uses. Ie. You need to set it to values like 15-20% for tradtional TPS/ETC% of 40-50%"

Roger that. I've got in the habit of logging etc pedal % since that seems to be close to what normally gets used in table look-ups for the tranny and so on. Atleast when there is no etc limiting going on.

The values I have in that table right now are from logged data on how much tps it took to reach 105 kpa at the givin rpms of the table. I'll scale that table back by .33 and see if it changes anything. It just seemed like in the logs that the magic number was 55 etc pedal % regardless of rpm, so I was assuming that there was a table populated my all 55's that I couldn't get to. Hopefully I just need smaller numbers. Thanks for the quick responce Bill.
08-10-2009
Chris@HPTuners

most tuners out here are setting the enable % to 5-15% on PD blower apps. It really has to be a lot lower than LS1 style becuase it is a non-linear weirdly calculated value rather than just a straight linear % TPS or pedal. This typically enables PE around 20-30%.

There is still only one enable table in the code (the is a Baro offset table but have only ever seen it calibrated to 0). Send your file to support if you want me to check it.

Chris...
08-10-2009
Frost

You're the man Chris!
08-10-2009
INTMD8

Fwiw on our car I disabled dynamic airflow and ltft's and tuned it strictly with the maf. PE set to 1.25 across the board and the car will go straight to 11.8-1 if I go WOT at 2k rpm.

Driveability seems perfect at all throttle/rpm/load positions though I can log something specific if you like.
08-11-2009
Bluecat

That was it. At 2000rpm it took a value of 9 in the table to get it to switch out of closed loop by 110kpa. That corisponded to etc pedal of 32% and absolute tps of 40%. Thanks for all the help everyone.
08-11-2009
5_Liter_Eater

Glad you were able to get it sorted.

Just want to chime in and say I think it's BS that something as simple as PE Enable is so damn complicated now. It's like GM is making things more complicated/confusing with each new PCM on purpose...:mad: I don't think all this complication is making vehicles run any better. [/RANT]
08-11-2009
Frost

Quote:

Originally Posted by INTMD8

Fwiw on our car I disabled dynamic airflow and ltft's and tuned it strictly with the maf. PE set to 1.25 across the board and the car will go straight to 11.8-1 if I go WOT at 2k rpm.

Driveability seems perfect at all throttle/rpm/load positions though I can log something specific if you like.

How much MAF do you have left from where you guys are now?
08-11-2009
Chris@HPTuners

Quote:

Originally Posted by 5_Liter_Eater

Glad you were able to get it sorted.

Just want to chime in and say I think it's BS that something as simple as PE Enable is so damn complicated now. It's like GM is making things more complicated/confusing with each new PCM on purpose...:mad: I don't think all this complication is making vehicles run any better. [/RANT]

this is what happens when you give engineers more processing power ;) you don't think Word, Excel, Powerpoint and Outlook really need a P4 2Ghz and 1G of RAM to run do you ? LOL
08-11-2009
INTMD8

Quote:

Originally Posted by Frost

How much MAF do you have left from where you guys are now?

I'll have to check the logs when I get back in town but I don't even think it's using half of what's available.

These new cars are gonna rock for big HP builds in terms of ease and simplicity.
08-12-2009
Blue-Z

Quote:

Originally Posted by INTMD8

Fwiw on our car I disabled dynamic airflow and ltft's and tuned it strictly with the maf. PE set to 1.25 across the board and the car will go straight to 11.8-1 if I go WOT at 2k rpm.

Driveability seems perfect at all throttle/rpm/load positions though I can log something specific if you like.

Just curious... If for some reason this car had a MAF failure or reverted to SD for some reason, wouldnt it go lean if the driver was to get it into boost?

Im by far no expert tuner, just was thinking about this and curious.
08-03-2012
10_SS

Quote:

Originally Posted by Bill@HPTuners

AFAIK the table that is currently in there is the ONLY table in the pcm we just decided to recycle the name more than likely instead of making up a new one which saves us time.

Regarding the tps gm changed how this is read & how it works on most all gen 4 pcm'd vehicles

This is what our engineer had to say regarding this a while back

"Try with smaller values for the enable TPS. From memory it's the same weird ETC % area - idle offset % the LS2 uses. Ie. You need to set it to values like 15-20% for tradtional TPS/ETC% of 40-50%"

My E38 Gen IV 2010 Camaro:
PE Throttle: 30% TPS PE = 60% Actual
PE Throttle: 5% TPS PE = 33% Actual

Quite a bit different.
08-14-2012
LSxpwrdZ

Here's another monkey bone to throw in these newer ECM's...

I tuned a couple of blower LS7's the last couple of day's and started off tuning them like I normally do by doing the VE first then switching to MAF only and calibrating that. When I finished up calibrating both individually I did a final pull running in mixed SD/MAF and the actual Lambda stayed lean even though it's commanding .77 lambda. So I changed the tune back to MAF only and did a pull and it was dead on commanded. Failed the MAF and ran the dynamic RPM up above rev limit so it would stay in SD and did a pull and actual was exactly what commanded read.

Someone explain that? I ended up having to disable dynamic early on at around 2500rpm and switch over to MAF only to keep the car happy and running the correct fueling.

I just thought it was weird that individually either of them operate normally but don't when mixed. These particular tunes were scaled 50% to regain headroom on the MAF table.
08-16-2012
Bluecat

I've seen that too. First noticed on auto camaros with maggies, as they build boost before the dynamic airflow high rpm disable kicks in. Fine it strait SD or MAF, but goes to hell in regular blend mode while in boost. What I saw was fueling literally cut in half for no reason, lol. Not had trouble with m6 cars though, and on ls7 cars I don't know that I've done a boosted one that build enough boost pre the maf switchover to show it. I've always assumed it has to do with the prediction coefficients. Those numbers are wildly different on the cars that don't act right, but to be completely honest I've never understood how those numbers actually work or how they relate. I know any time I've tried changing them or tried to copy over from a different tune that they go completely stupid. I assumed there was more tables than what we see involved and importing from another tune dosen't work because all the settings don't get brought over and end up miss matched. Even if they arn't the problem, I'd still like to understand them better.
08-16-2012
LSxpwrdZ

This particular LS7 had a Eforce blower so that really killed the 3000-4000rpm disable for me. Basically just had to lower the dynamic disable rpm to keep it happy. It was a mild setup so it didn't have much erratic MAF behavior either.