Originally Posted by RS211

When a GIAC dealer tells me Porsche can scan the ECU for reflashing and stored performance history I kinda believe him. I'm sure if there is a major driveline issue the dealer will call in the factory rep to do the indepth scanning.
Well I guess there are no dyno sheets from any vendors that show claims in performance other than just full throttle dyno pulls. Or are there any before and after exhaust system dyno sheets showing the gains being lost from the freer flowing exhaust with the ECU adapting back to stock settings, or dyno sheets showing the IPD Y manifold gains being removed by the ECU...

If you are going to sell a tune showing proof is the best way to do it..

I'm not asking for code just the normal dyno sheets any car guy would ask to see before purchasing anything that makes performance claims...and then have them fade as time goes by without a warrantee voiding reflash tune...

Again I'm not knocking the GIAC reflash, I would just like to see more than just a wide open dyno sheet...I don't mash the peddle every time I exit a corner in the canyons so it's that tip in response data that I would like to see, GIAC vs stock.
When being trolled by fools and responding is not abrasive the way I see it.

I joined to learn something, not to make friends with sheep or those that correct my spelling.

At this time I'll just sit back and wait for someone to write an undetectable tune and enjoy the response and tone of my new exhaust..

Originally Posted by wrs

Look, this is software and data. The most common way to determine if anything has changed, a scan if you will, is a checksum. We used MD5 checksums on our code, it's pretty reliable. I am sure that the ones used now are longer but nevertheless, any change in data or code will be easily detected.

Originally Posted by RS211

I wonder if anyone can do a data dump/wipe clean and insert the changes without showing up as a modification ?...
I'm no tech guy so my wording may be off.

Originally Posted by wrs

No, the checksum wouldn't match. That is the point of the checksum. The manufacturer will checksum what has been delivered and that won't change. Things that change will be the parameters that are modifiable through any adaptation of driving conditions/habits and stored. The tables that determine boost, fuel mix, timing and other variables that are adjusted with loading will be fixed data and should not change but these are what GIAC and any other flash tuner will modify. Any change in that data will result in a different checksum than the one stored when the ECU was flashed by the manufacturer at delivery. Typically the checksum is encrypted with a key before being stored. This way the mod companies have a difficult time making a mod and storing a new checksum to fool either the manufacturer or the software itself which may refuse to run if the checksum doesn't match.