That's a good question. I think I've seen some in car vids of people making pulls with a piggyback. The boost gauge showing 18/20 psi. Hopefully someone will jump in to clear it up.
It had been brought up as a question. With a piggyback, is your boost gauge showing the higher boost. For lack of better word, the piggyback fools the ECU which in theory doesn't leave, shall we say any (being the key word) evidence of out of range operation. The vendors who sell said components state this as a key selling point. It's kind of like advertised HP gains/claims you read about. Whenever a product reads "up to X HP gain" in weasel word talk that means from 0 to whatever BS number their showing. This legally releases and protects them from you the consumer that may confuse mo noise with actual HP gain. The informed buyer aka gearhead typically doesn't have to worry about this. Now if you find yourself eyeballing that Tornado on Egay you may be in the" there's one born every minute" crowd. I hope the answer is yes on the following. In the event of a Powertrain failure when the vehicle is taken in for some high buck warranty and they put a seasoned master tech with a black belt level in extracting all available data from the factory Consult, will he see something that the mere mortal Tech could never have conceptualize. I gotta go guys, my Mom is calling me for dinner and meds.
Yes, any turbo car will if you listen closely enough.