Another thing which influences tuning is the orientation of the air intakes of the INS box.
When they're positioned towards the front of the car you will create a RAM-air effect in the straights, thus leaning the engine.
In touring we all position the intakes towards the rear.
I don't know if this is a common thing to do in 1/8 as well but I think the effect will be even worse on a 1/8 because the intake is out in the open, in clean air.