Join Date: Aug 2011
Location: Albuquerque, NM
Ferrari Life Posts: 11,849
It all comes down to what parts of the system you put on a 550 or a 575M. The springs, anti-roll bar and hydraulic steering ECU are identical (same part numbers) on the 550 and 575M with FHP. The brakes were identical on FHP and non-FHP Maranellos except for the Pagid Orange 4-4 racing pads and Rosso Corsa paint..
The big difference in the two set-ups for the 575M and the 550 is the shock absorber ECU. There was a 550 FHP specific Bilstein shock ECU, while the FHP 575M came with whatever stock shock ECU was being fitted at the time the car was being built.
So if you wanted to improve the handling on a 550 and not make it quite as hard riding, putting on the FHP or HGTC springs and the HGTC (FHP no longer available) anti-roll bar, without fitting the Bilstein FHP shock ECU, would do it. Alternatively, leaving stock springs and anti-roll bar in place, the FHP shock ECU alone will measurably tighten up handling without affecting ride too much.
There is an amazing difference in how handling is affected by shock ECUs. This is especially evident in the 575M, where the first Sachs Sky Hook shock ECU was set up way too loosely. Quickly remedied, but a very worthwhile upgrade for early 575Ms is a later shock ECU. Bilstein seem to have gotten it correct on the first try with the 550 shock ECU for a reasonable compromise between ride and handling. The Mannesmann-Sachs shocks and actuators on the 575M, however, are much more robust and reliable than the Bilsteins on the 550.
Present: 575M 135171
Past: Dino 246 GT 02984, 365 GTB/4 14009, 308 GTS 25125
Every day I look around, and if nobody is shooting at me, it is a pretty good day.