Side by side comparison between my runs with my friend in his 981 Cayman S during the JRP track event at Canadian Tire Motorsport Park. Both cars are manual and on the same tires. Mod lists are below. Both cars definitely can find more time; I braked earlier into 2, 3 and 8 to be conservative with brakes and he is relatively new to the track so he's also finding out the limits of his car. 

2018 M4 ZCP
-Ground control camber plates
-K/N filter
-Apex Sm-10 wheels
-275/305 Nitto Nt-01
-Schroth quickfit harness
-PFC-08 pads
-Endless RF650

2014 Cayman S (981)
-Monoball front/rear
-solid bushings
-Gt3 control arms
-Rays TE37 
-245/275 Nitto Nt-01
-Ferodos Ds1.11
-girodisc rotors
-Castrol SRF
-Slight tune for midrange torque; no peak power increase