The upgraded engine in manual cars gets a flatter torque curve as well, helping improve responsiveness. (kbb.com)
... and here is an interesting print out of torque curves, comparing a 40 mm length with a (ridiculous, but interesting) 330 mm length. (mechanics.stackexchange.com)
, respectively, while sporting a broader torque curve for more immediate and powerful acceleration response. (chicagoautoshow.com)