Originally Posted by Memphis1
alright... i dunno know what part of the 35i and 35is are one in the same you guys don't get... if you just need the excuse because you paid more than fine, but don't spread it around as if it was a fact.
anyway... the ESS stage II willl make the 35i and 35is equal, the 3 more hp that you get in your 35is from factory becomes irrelevant with any tune, ESS, Dinan, JB whatever.
I do not own a 35is so have no reason to excuse anything, Sorry. The engine is the same but the 35is has the following: Different internals (more durable), different gear ratios, upgraded fuel pump (the one that now BMW offers as an upgrade to all the HPFP failures), a "little" less restricted exhaust, performance cooling system and of course the different ECU with overboost function on the ECU which respectively will give more power on an tuned car (and thats something you cant retrofit). And THATS why ESS (for example) raises the RPM limit to 7200 on the 35is/1M than 7000 on the conventional N54 engines. It's Basically the 1M tweaked engine.
Not bashing on the 35i, i actually own one. Just setting facts straight =)
Ps: the difference between the is and 35i in performance is around 30hp not 3. Proven on dyno's.