[PrematureApex]

Originally Posted by nicknaz

Regarding piggyback vs flash tune, my understanding has been that piggyback is "tricking" the ECU by intercepting signals, so because ECU is not aware of the actual engine load, it can't advance or retard ignition effectively and it will only retard timing when the knock sensor detects something (e.g. piggyback can't alter fueling and timing at a very granular level). That's why BMS uses the "back end" DME flash (e.g. flash tune) in addition to the piggyback.

It's worse than you thought....

You stated: The piggyback can't alter fueling and timing at a very granular level. You should probably know that piggybacks do not alter timing or fueling (sans a flex-fuel wire install), at all. That's all the factory DME. And it has been shown, time and time again, that the factory DME is actually very, very good at timing control, hence why the JB4 works so well and has been so successful. Yes, the timing control is limited to the DME and its use of the knock sensor. But it works well. Knock is not an issue.

But you mentioned the DME not knowing actual engine load, presumably as an attempt to identify a "fail safe" that's not effective when you use a piggyback. But aren't you're ignoring that the aftermarket reflash is going to have to alter that level. So perhaps your factory "fail safe" wouldn't be retained anyway?

Regardless, no one is arguing against flash tunes, they are superior in a number of ways. Yes, flash tunes are often used underneath a piggy in order to implement a more advantageous timing curve while retaining some of the things the piggies do well.

No question 3900 lbs. is a lot. That wasn't the point. The point was, it weighs the same as a 335 xdrive sedan. So are you suggesting that it's wasted for anyone to put a suspension or a swaybar on one of those? BMWs staple sports sedan?

A better handling car is a better handing car, period. Aesthetics aside. Why would you have an issue with someone wanting to make their family hauler drive better? You only like better handling if you're driving a sports car?