Jimmy-D

I thought the second position was the one before you turn the car over?

Jimmy-D

Nobody has yet answered the question that why would one have to do this adaptation if you have a tune

jmartpr

I have also read in some posts about disconnecting the negative from the battery during the installation and the ECU will re-learn everything once the power is back....

jmartpr

If I have to guess given my limited knowledge of Porsche ECU's I guess most tunes would address fuel/timing calibration but the TB calibration/adaptation is probably to give the ECU the range of operation for the new TB.....probably the ECU recognizes that the TB is new and different. You stomp on the pedal and the signal send from the TB goes out of the range pre-established on the ECU for the stock TB......
so you get a CEL or less performance given that the throttle opening is out of place on the ECU fuel and timing maps. If there's an option to calibrate with PIWIS best guess is that it's necessary every time you change the TB.

d00d

I got this from the 987 IPD plenum install document, not sure where Greg got it initially, probably from a shop manual.

Depends on how you look at it I guess.
If off is 0, power would be 1st, and start would be 2nd.

Jimmy-D

^Correct

CAlexio

We need to summarize what we know almost, but not sure I'm the best to do it as I have only read on here the info. What I gather thus far is:

-with tb and plenum you can recalibrate during ignition with the gas pedal procedure.
-without a tune you will get a cell no matter what
-the hanging throttle issue has happened with a tune while under heavy usage at the track.

Any other core conclusions we can draw? I have yet to install my Tb and plenum and was keeping my fingers triple crossed that I wouldn't have to do the tune in order to avoid the cell... Kind of bummed now

kitwetzler

That's good news, I'll try there again. I called and the SA I got after a 15 minute hold had no idea what I was talking about :P

kitwetzler

AFAIK, the 981 SDI9 does NOT do the throttle body adaptation this way. I'd love to be proven wrong, but unless you turn the car to the on position, the throttle body doesn't move at all in the 981. I saw that in the 987.1 guide but the 981 does not do this.

d00d

Good to know, thanks.
Even so, usually a procedure like that doesn't go away between ECU versions from the same company, unless that information is from the older Bosch ECU.
If anyone can find the source that would be great.
Looks like the 987 DFI SDI3 is also from Siemens, and the Durametric can start the adaptation for that version.
Maybe what jmartpr describes causes it to start an adaptation, or it will just start on it's own at some point.

jmartpr

If we could get the details on how the adaptation is done with PIWIS or Durametric.....IMO I would think that letting the car do it's own calibration on a DBW (drive by wire) part would be more risky and less precise than providing the ECU manually the minimum and maximum points for the TB operation.....unless the TB has the ability to send to the ECU throttle plate percentage opening and the ECU adjusting it in relation to gas pedal positioning, but I doubt this could be the case.

d00d

In the Audi world the Durametric analogue is VCDS which provides more functions overall, and the TB adaptation there is accomplished automatically by just starting the process;
http://wiki.ross-tech.com/wiki/index...ment_%28TBA%29

BGB Motorsports

Thanks for the support. It's amazing how all of us can share information despite selling competing products. Reasons like this are why those that choose to collaborate will always go further than those that do not.

As of right now, I know of 2 ECU vendors that have been able to turn off the request to the instrument cluster to throw the code for the MAP/MAF being improbable. Prior to this, doing the throttle body adaptation used to buy you some time but it was never 100% guaranteed as I can think of a story from everyone about how sometimes the CEL would return and then go away again after a while.

Every single time you program the DME you must do this adaptation or the car will run in what's called Reduced Engine Power UNLESS the battery gets unplugged during the entire process; if so, you can navigate through it and the car will run and will not be in Reduced Engine Power BUT the CEL usually returns. This is why tuners have implemented this into their protocol so that the writing software does it or else there's no way the car would run well after programming.

Here's the thing...while everyone is saying this is all you have to do, i'm still skeptical that it's a true 100% success ratio. Some people have been successful, some have not. It seems that those that do it, drive around on the street and they're fine but once you drive the car at WOT and mash the gas half a dozen times, the rumors are that the next time you turn the car on the fault comes back. As of now, both Cobb and my other tuning partners have found a way to get rid of the CEL on the cluster. You could try another dealership...I can't imagine anyone would say no if you said "charge me 1 hour's labor and please re-adapt my throttle body." I can't believe they would say "no, we don't want to" but then again, some dealerships are hesitant to touch anything and others are super gung ho.

I too was baffled by the different sound that he had afterward but he said once he went to the dealership, it cleaned up. I'm still unclear though but if that's the report, then I trust it.

Agreed. The calibration is designed to calibrate the pedal position to the voltage sweep of the throttle blade. Every time you turn on your key, that click you hear is the throttle plate waking up and talking to the ECU.

To confirm based on what I know:

1.) I don't think that's the same as doing a TB adaptation with the PIWIS but I am not 100% sure because the ECU stores a fault if you put a new throttle body on and do not run the adaptation. HOWEVER, if the car goes to sleep long enough, there's a good change it will resort to a self adaptation because others have installed throttle bodies and have been able to drive their cars without doing it with the PIWIS BUT, the CEL has returned even though the vehicle has functioned fine post install.
2.) Without a tune there's an 80% chance that you will get a CEL but I tell everyone that they should expect the CEL 100%. Some folks say they have not, Fabspeed reports not...I'm not refuting what they're saying but i'm a skeptic when it comes to how fickle these cars are and I can't believe that will fix it 100% because I've gotten calls from frustrated GT4 owners who had a dealership clear the CEL and had it return.
3.) The hanging throttle body has happened with a tune AND without a tune. Someone on here PMd me to say that some of the Club Sports experienced an issue on downshifts with AND without programming at Laguna Seca this past weekend. So...the more I dig, the more I find.

In addition, I got impatient and called IPD and they said that of the 200 981 plenums they've sold and of the 60 GT4 specific sales, only 2 people have reported the issue of the hanging throttle. At this point, it's rather inconclusive as to what the cause of the problem is but it's clear that it's not a result of aftermarket mods. My apologies for the lack of responses lately but I've been doing homework on this subject and did not want to chime in until I had gathered more facts. I am still a bit baffled though and i'm ready to wonder whether the auto blipper is confused. We just finished the buildout of a PDK 2.7L 981 race car that now has a 3.8L 991 motor, got re-coded as a GTS and then flashed with Cobb tuning and it ran flawlessly for almost 400 miles. No issues with hanging anything. I can list almost a dozen 981s that we have built that have larger throttle bodies. Before the GT4 and the recounts of the hanging blade, I had never ever heard of such a thing. Make no mistake though...now that a few race teams have had problems and my phone has been ringing non-stop, we should have some more information over the next 2 weeks. Something is causing a problem somewhere...we just need to find out what and where.

jmartpr

John...is there a way to know if the engine is running in the Reduce Engine Power (REP) mode? Any codes? If for some reason you are at REP mode can unplugging the battery for a long period reset the ECU into regular mode?

user1029

Does a CEL from race headers throw the car in limp mode? Or is it just a nuisance?