Originally Posted by SteveMD
Hmm.. I hear you and agree but I find it hard to believe that a mild cam/compression tweak on the new motor couldn't produce a reliable 280-290HP.
Tuners will find this hard because of the valvetronic/VANOS/ECM but BMW engineers could probably do it during their lunchtime game of Minesweeper.
A set of cams and an ECM reflash for say $1000? Who's in?
Without wanting to sound too condescending, but you donīt know much about the latest technology found in modern cars such as a BMW E90 do you? The days of hot cams are long over. Most modern performance engines have some sort of variable valve timing. Have had such for years.
On an N52 engine you have double Vanos. So both the intake and the output camshaft get more or less fully variable timing by rotating the camshaft relative to the crank hydraulically. Thus the ECU can give the combustion chamber a soft cam profile for low revs thus producing higher troque and sharp cam timing for higher revs.
Plus the N52 also has Valvetronic meaning the lift of the valves is fully variable (there comes the bigger lift your hot cam used to provide).
Thus a different cam could not really improve much on a double vanos valvetronic engine. It basically allready has the hottest cam thats possible while compensating the ill efects a hot cam used to have (erratic idle, little torque at low revs) through lots of hydraulics and electronic gadgetery.
As for a compression tweak: Well the N52, again like most modern performance engines, allready runs at the maximim compression it possibly can without uncontrolled (early) combustions. in fact it wouldnīt last a thousand miles if it were to run with its maximum settings without the aid of a knock sensor (which detects early combustions) that is used to allign the ignition along the maximum ignition retard the current fuel allows. Raise the compression on such an engine and youīll simply get the knock sensor calling for help and the ignition turning back
Again, your talking old school. In the early days, you could raise the hp of an engine by rasing the compresion and advancing the igintion if you made sure ythe upgraded engine was run on high quality (high octane) fuel.
I really donīt want to step on your shoes here, but I think your idea of an engine improvement is stuck a bit in the past. Hot cams are fine for more hp from a 64 Chevy small block.
On an N52 engine things get a little