Mileage before dyno??

[gbvetracer]

Does anyone know the facts about how and when the GT's computer will be ok and ready for dynoing? We heard somehow the ecm or pcm doesnt program itself until a certain number of miles have been driven? Never heard of such a thing..... I know the opinions on engine break-in are different with everyone, but this idea that the cars computer might not act normal under WOT until a certain number of miles have hit., is a new one to us. I would think just letting the car run for 20 mins 3 days a week would help seat the rings and break the engine in....while varying rpms... but that wouldnt run up miles on it obviously.... any help would be appreciated... thanks !

 

[GT Tech]

There was a limiter built into the PCM from the factory. If I remember correctly, it was 3 miles, or 30 cycles of the key. It was a one shot deal. Once it went off, it would never kick back in. It limited the motor to 4000 rpm, and 0 boost. You would know right away if it was still was active.

I was one of 2 factory test drivers. One car a day, (in good weather ) got a 25 mile test drive. After the drive, we put a small sticker on the window stating that the car was selected at random to be audited for quality purposes, and the mileage accumulated.

Hope this helps :thumbsup

 

[Indy GT]

As engine Electronic Control Modules (ECM) become more sophisticated the more the engine manufacturer can do with them. The term "adaptive logic" has been coined for these newer high power ECM's. Thus the electronics "can" learn how you drive the car, the power the driver typically requests and "learn" how the car is driven. Some (not the GT ECM) can then alter engine paramaters to curb delivered power (spark advance, fuel rates, A/F ratios etc) and thus increase engine life (and possible warranty claims).

There is some knowledge aquired by the ECM in our GT's which fine tunes certain engine paramaters relative to indigenous baseline curves within the unit. If you ever disconnect the battery to change out etc. these refined paramaters are lost and the ECM must reaquire new refinement algorithms based on the driver habits after the battery disconnect. I have been told the adaptive logic will/does not limit full engine power on the GT. Note this ECU logic discussion is different than the 3mi/30start initial reductions discussed by GT Tech above. As he correctly states once this initial life threshold is passed it does not ever reoccur.

 

[Fubar]

If you ever disconnect the battery to change out etc. these refined paramaters are lost and the ECM must reaquire new refinement algorithms based on the driver habits after the battery disconnect. I have been told the adaptive logic will/does not limit full engine power on the GT.

Does this mean, if you drive the car conservatively on the roads and then take it to a Dyno, you should disconnect the battery and allow the ECM readjust?

 

[Fubar]

I was one of 2 factory test drivers. One car a day, (in good weather ) got a 25 mile test drive.

How long did you work at Ford before you got this job. I was thinking about putting in an application at Bugatti.

 

[nota4re]

After an accumulation of ~100 miles (conservatively), the ECU should have had sufficient opportunity to log its first tests and be in a "normal" run mode. As I understand there are essentially three states of the GT ECU.

1. ECU was pre-programmed to have a hard throttle limitation for the first ~5-10 miles of odomter reading. This was an intentional saftey feature to prevent any temptation of pre-owners of having too much fun while moving the car around and on/off transporters

2. The ECU does not achieve "normal" run mode until it has at least successfully run all emission level test one time. The tests are keyed off of different driving parameters and may take 50 miles or more to complete.

3. Following the achievement of all tests, the ECU remains in adaptive mode it's entire life. This is how ECU accomodate different driving conditions and the natural lifespan of the engine where efficiency will begin to erode (after 10's of thousands of miles.)

Ask 100 people the best break-in for an engine and you'll get a 100 different answers. In my reading - and in applying my own weighting to sources I trust and those that I do not, I believe the cornerstone is high cylinder pressures early in the engine's life are very desireable - and especially if they can be had without max rpm. Easy with a manual trans. It means WOT in higher gears and letting off well before redline. Rewind and repeat - occasionally.

 

[GT Tech]

Fubar,

I worked for Ford for 25 years before I went on the GT program. I spent 3 1/2 years on the GT, then took an early retirement. :thumbsup

 

[BlackICE]

Fubar,

I worked for Ford for 25 years before I went on the GT program. I spent 3 1/2 years on the GT, then took an early retirement. :thumbsup

What a way to retire, after working on the best car Ford had ever and will ever build! Thanks for all of your contributions in making this car happen.

 

[06fordgt]

I was told first 500 miles car controlled, then computer allows full use of motor.

 

[Indy GT]

ECU Technical

Thanks for the highly informative post nota4re! Although I did not have all the specific ECU facts at hand, your technical discussion aligns with what I have been told by the powertrain engineers.

As to disconnecting the battery prior to a dyno run, I would not think that is a good thing to do (or necessary). Let the ECU control the engine with it's acquired logic as to how the car has been driven.

I also concur with the high BMEP during break-in to better seat the rings. Pretty easy to do with the manual transmission as noted, and the synthetic OEM oil is just fine for the break in procedure.
Just my $0.02 worth....

 

[nota4re]

As to disconnecting the battery prior to a dyno run, I would not think that is a good thing to do (or necessary). Let the ECU control the engine with it's acquired logic as to how the car has been driven.

Agree... no need to disconnect the battery before a dyno run. FYI: Druing typical dyno run to measure TQ (and its computed derivative called HP), the care is at WOT. As such the ECU is in Open Loop Mode. Pre-programmed internal tables are used along with sensor input (MAF, IAT, etc.) to get the right values. Learned values such a fuel-trim mostly help the ECU to achieve 14.7:1 more quickly while in Closed-Loop operation.... a mode that is really never in play on the typical dyno run to measure TQ.