Quote:
Originally Posted by buildbright
I can respect that piggybacks are not for you but don't spew incorrect info. Any aftermarket item that changes engineered variable's can put increased stress on the engine. Thus causing decreasing reliability. This could be a simple exhaust or air intake.
If you don't like piggybacks don't sell them but don't say they are not safe because you personally don't like them. I personally am going to trust Hartge that has been tuning since 1971. Turner Motorsports which actually has a successful Motorsport record. BMS and others which have 10's of 1000's piggybacks installed and successfully working. What is you experience?
|
What sort of "incorrect info" was posted about piggybacks?
Any tune that increases output will increase stress on engine and transmission components, no one is arguing that.
The post by Ilia@IND only pointed out some of the limitations of a piggyback, giving examples of which parametres not being able to be controlled by a piggyback. Hardly any news in that at all, kinda like pointing out the difference between a DC9 and a F16 fighter jet...
For a mild tune a piggyback ala Hartge, AC Schnitzer etc works fine, since it only adds a mild increase in power that is well within safety limits (I assume). If you want a serious tune, you need to change the software.
One other major reason German tuners often use a piggyback is because that makes homologation for road use easier and cheaper (as required in EU). With a piggyback you can use stock software in the DME/ECU for the emissions test cycles, meaning the car will still comply with EU emissions legislation without need for expensive complete new tests. The piggyback only becomes active outside the EU-cycle criterias (like at full throttle, above certain RPM's etc).
In Germany it's illegal to market or sell any tuning items that isn't accompanied by a certificate of compliance with German/EU-legislation (according to a ruling by a German court).
So piggybacks are preferable to German tuners also because of ease of homologation, not because they are better. And they use one type/brand of piggyback that is adapted to fit different models. That means that things like ElectroMagneticalCompatability etc. don't have to be tested and documented for every installation. They can use the same documentation since the piggyback hardware is similar.
AC Schnitzer M5 piggyback fitting instructions:
http://preisliste.ac-schnitzer.de/ac.../121410710.pdf
520d TÜV approval (took this one since it's both in German and English):
http://preisliste.ac-schnitzer.de/ac.../121490170.pdf
Interesting that the description reads:
"Modification of the injected fuel quantity at full load"