150 B vs 150 C

[bartmc]

I know jimC flies a 150C and some of his numbers seem really fast for my 150B.
I was looking here
http://www.pilotfriend.com/aircraft%20p ... r/2/20.htm
and here
http://www.pilotfriend.com/aircraft%20p ... er/3/4.htm

and noticed that the 150C got 10Knots from the factory faster than the 150B (107 Vs 117)

How'd they do that?

 

[JimC]

 

[bartmc]

 

[Frank L]

 

[JimC]

 

[Raptor05121]

 

[JimC]