If you have been tunned on 150 shot pulling 5* timming on br7ef's and you tune for 250 2 8* timming. When you decide you want to drop back to 150 shot do you need to retune or just go back to your already tunned settings and run it?

 

You should just be able to drop it back to 5 degrees for the 150 hit so long as you have a way of doing that, and no other mods have been done in the meantime

 

You will need to change jets, and change timing back to what it was.

-Garrett