maybe not. The use of a turtle to affect plenum volume, carb signal, etc. sounds like a good idea but without a dyno test and track results, it's hard to say. Many drag racers do swear by turtles to generally improve low speed operation w/o affecting the top end. The great thing about turtles is one can swap different ones in quite quickly although minor jetting changes may take a tad longer.
http://www.brodix.com/parts/turtles/turtles.html