StatoJase

Hi, I have been running a gt4294 on my 408 which is too small for the engine and am going to upgrade the turbo soon, Everything else being exactly the same apart from the turbo will I need to retune this thing? The gt42 choked the hell of my engine on the dyno. GT4780 is what I am looking at at the moment.

MUSTANGBRKR02

iTrader: (91)

Yes you will

itsslow98

iTrader: (18)

Yea itll likely have different spooling characteristics and a lot more air going through.

SPRAYED 01

iTrader: (22)

Yes get it tuned

StatoJase

Yeah ok thought I would but was hoping to get away with running low boost until I had the facilities to get tuned again. Might hold off on the turbo swap. Will running high pre turbine back pressure cause any real dramas for a street strip car other than choke the power

Camaro9969

iTrader: (12)

Anytime you make any changes to airflow or basically anything it will need some sort of retune. With the turbo if your tune was spot on most likely will need just some minor tweaking of the ve table but will not be much

Ryans99ls1

iTrader: (16)

I swapped from a TC78 to a PT7675 and my AFR got a half point leaner. Not a big change but i still had it retuned. Picked up a ton of power though