I have tried this experiment before. The answer is they spew different amounts. I'm guessing the reason has something to do with the carbon content in the drinks. And in case you're wondering, it's a fun (yet messy) experiment!
If You Shake Up Different Kinds Or Brands Of Soft Drinks (e.g., Carbonated), Will They All Spew The Same Amount?
Sounds like a fun experiment; just make sure you're not wearing good clothes when you try it. I would imagine that would create one sticky mess!