BlackS197Stang

I just got an '06 GT with a Whipple HO kit. Woo hoo! It still has a custom dyno tune from when it was in CO (high altitude), when it had a 2.9 pulley. The most recent owner before me kept that tune, but changed the pulley to a 3.5. According to the boost gauge, it's making about 9 lbs of boost at WOT. Another issue is it may not be emissions friendly, which could be a problem at inspection time, but it's probably OK. I'm wondering if I should just download the stock Whipple/Ford Racing tune. If so, I was looking at the included Pro Cal flash tool and it has the instructions on the side of the unit. The 2 options are "performance calibration install" or "stock calibration reinstall". I assume the latter means the stock engine (pre supercharger) tune. Would I need to load the stock tune back in the car before I load the performance/Whipple tune, like you do with an SCT tuner? Or will the Pro Cal just write directly over the custom tune?

Simon1

I would leave it alone and not touch anything.

However, if you must. Use your SCT and return it to stock and then flash with PRO CAL tool.

moosestang

Always return the stock tune before flashing a new tune. The Pro cal tuner will save the stock tune.

Diabolical!

+1, but if I were in your shoes, I'd pony up for a new dyno tune. It's the only way to get the balance of performance and longevity that you're comfortable with.

07 GT E UPP

+1 to the new custom dyno tune !!

908ssp

True dyno tune. You never know what they might find and the phone tune won't find it.