I have a quick question?
 

I have a question. There's a guy who has the exact same setup I do and got his Z dynode at the same place but he's getting 10 more horsepower than I am. Does anyone know why that is?

EXACT?!?!?! Same tuner??? Same day??? Same tires??? Lol


All these factors can make a difference

As DE½ pointed out, you don't have the exact same setup. They may be very similar, but they're not the same.

10 HP is about 3% of advertised, stock output (332 HP). Between differences in cars, precision of dyno, and other factors, that's not enough difference to mean anything.

Do you both have same transmission type, same trim level?
Same wheels and tires?
Same amount of wear on the tires?
Were the tires on each vehicle inflated to the exact same PSI?
Did your friend have an oil/spark plug/air filter change recently and you didn't?
Were the oil and coolant temperatures the same on each vehicle during those runs?
Was the ambient temperature/humidity/barometric pressure exactly the same when each car was run?
Did they strap down the cars to exactly the same tension?

Lots of **** can cause a difference in dyno reading, I wouldn't sweat it too much.