Quote:
Originally Posted by RJC-1
Quote:
Originally Posted by subzero05
a properly designed and engineered piggy back unit will never "defeat" the "pre-set" factory limitations set by the ECU. What is "sees and records" never changes. at WOT for example there are preset boost "limits" the ECU will expect to see. while a piggy back unit may alter the "signal" being sent from the sensor connections, the ECU itself still only "sees" those limits, therefore nothing is actually ever changed from stock. However in case of the JB4 unit for example, if you plug into the OBDII port , it can leave a fingerprint trace that something was altered if any changes are done thru it. Just trying to give some additional info on how they work etc.
|
Good to know, thanks, pardon my ignorance but if it's not changing/defeating factory preset levels (boost, timing fuel mix etc), then how does it increase power? My dealer says BMW frowns upons mods and if trouble arises, and it may have something to do with the mod in one way or another, the warranty may be negatively affected. I'm more than satisfied with the power as is and wouldn't risk it, but to each their own  |
When the ECU requests a certain boost target, the JB4 overrides it according to the map's preconfigured settings—it can do so because it's inserted in between the ECU and the turbo controller hence the term "man in the middle" that someone used earlier. As a result, it can "override" the requested target either additively by adding +4 for example to whatever the ECU's target was (that's map 1) or it can use absolute values ignoring what the ECU said entirely.
On the warranty question, yes, they're correct—as is mentioned here frequently: you pay to play.