[tazandjan]

I get a lot of questions on the differences between the 550 and 575M, so here is something I wrote up for the 550/575M owners that may help those trying to decide which model to buy. Let me state upfront that both of these cars are about as bullet-proof as Ferraris can be, and either are great cars and great Ferraris. We have many 550 owners who really prefer the looks of the 550 and only 2/3 as many (2064 vs 3083) who prefer the looks of the 575M. Three pedal purists also like the 550 because it is difficult to find one of the ~12% (246) of 575Ms that were three pedal cars.

So here you go, another attempt to bore you to tears. If you have insomnia, read this just before bed time.

Here are some comments on the 550 and 575M that may help, leaving out all the obvious facts like the larger engine and availability of F1. First similarities. Brakes are just about identical with 330 x 32 mm F and 310 x 28 mm rear rotors with 4 piston Brembo calipers F&R. One of the rear pistons on the 550 is smaller, but that is the only difference. Transaxles are virtually identical with triple cone synchros on 1st and 2nd and double cone on the rest. Clutches were identical. Steering racks are the same. All 550s (and the 456/M) had a steering position sensor that improved handling feel, and only 575Ms built in ~Dec 03 or later have one. Both 550 and 575M were available with the Fiorano Handling Package, but the 550 only late in production.

The 575M has a larger intake opening and improved front brake ducting, but the bodies are very similar, with all aluminum panels, except for steel doors, over a steel space frame. The biggest difference in the engine, besides size, is the Motronic 7.1.1 ECUs on the 575M (5.2 on the 550) that provide coil on plug ignition and very precise fuel metering. COP is a big advantage because it eliminates all the high voltage passing through the spark plug wires from the 550's two coils. The Denso COP coil packs have caused very few problems, unlike the early Beru coil packs fitted to BMWs and other cars. COP ignition and more precise fuel metering have allowed the idle on the 575M to be reduced to ~750 rpm from the 550's 1000 rpm.

The more sophisticated 7.1.1 DME (also fitted to the 360, F430 and 612) has allowed a much more sophisticated exhaust bypass schedule, open at idle, closed at 1000 rpm, and reopened at 2720 rpm and 64% throttle vs the 550s wide open throtle at unknown rpm. The camshafts on the 575M are a little more agressive than the 550's, and peak power is produced at 7250 rpm vs 7000 rpm and peak torque at 5250 rpm vs 5000 rpm. Both hp and torque, however, are superior to the 550 at all rpms.

The 575M has a higher flow water pump than the 550 and also radiator fans that move more air at lower rpm. This has kept the 575M from having very many cooling problems so far.

The wheels and tires on the 550 and 575M are identical at 8.5Jx18" F with 255/40 18 tires and 10.5Jx18" R with 295/35 18 tires. The standard 575M wheels are lighter weight, however, and 19" wheels were optionally available. The 575M was the first car fitted with a Beru TPMS system, which has been reliable except for the short life (3-5 years) of the sensors mounted to the valve stems on the inside of the wheel.

The interior of the 575M shares an instrument cluster design with the 360 and F430, with detail differences vs the 550's mix of centrally located and center dash instruments. Not much to choose between the two. The driver's seat on the 575M is fitted with standard memory.

The ABS system on the 575M is a generation newer than that on the 550 and, combined with the digital throttle on the 575, provides a far smoother and less intrusive ASR system.

The Bilstein shocks and the shock actuators on the 550 (and 456/M) were replaced with nearly bullet-proof Mannesmann-Sachs shocks which will probably outlive the owner. A huge improvement in reliability.

The 575M was partially fitted with silicone water hoses for longevity and with much improved motor mounts, but nearly all 550s have been upgraded to the 575M parts. The 575M has far superior and far cheaper fuel pumps that are less affected by ethanol in fuel.

There is an old wive's tale that the 575M is more electronic than the 550 when, in fact, some 550 ECUs, like the fuel cooling and ASR exclusion ECUs, were eliminated on the 575M. Neither car, however, has had many problems with the ECUs, so the point is moot.

Hopefully this will give you some idea of the main differences. There were 3083 550s built, all with three pedals, and 2064 575Ms, 246 of which (~12%) were three pedal cars. The transmissions on the F1 and three pedal cars are identical, as are the clutches. Only the T/O bearings and shifter mechanisms were different, plus the addition of a clutch position sensor and one additional angular speed sensor for F1.

Taz
Terry Phillips

[JazzyO]

Fantastic post, Taz. Question - I always thought there were around 3,600 550's built. Does the Barchetta explain the difference with your number?


Onno

[cribbj]

Taz, great post, and just another point to add; the 575 came with DBW, where the 550 has a standard throttle cable.

Small point unless you're like me and want your right foot firmly connected to the butterflies!

[tazandjan]

Onno- The 3600 number came from Cavallino and the fact it is a nice round number sounds like it is an estimate. The 3083 number actually comes from Ferrari, and to that needs to be added 33 World Speed record cars, which I earlier stated incorrectly were part of the 3083. The Barchetta at 448, the WSR and the 3083 would be 3564, so not sure where Cavallino got that number, since they list all three separately.

Taz
Terry Phillips

[tazandjan]

John- Affirmative, I mentioned the 575M's digital throttle made for a much less intrusive ASR system. The 550 throttle cables are not directly connected to the butterflies, but actuate two potentiometers that control the opening of the butterflies and fuel mixture through the Motronic DMEs on each bank. The direct connection to the butterflies has been gone a long time. My Dino, Daytona, and 308 GTS had a direct connection to their Webers, but not these modern marvels of fuel injection.

Having flown aircraft (F-16) with no mechanical connections to any of the controls, I kind of like digital controls.

Taz
Terry Phillips

[Jimmy Chen Shiba DDS]

Taz, I am in tears and awe, not from boredom, but because it is way over my comprehension capacity. Seriously, what a fantastic information. If I were in the market for 550/575M, these are the facts I would luv to have.

Well,...I presume you would be bored to death if you ever see my 1958 Abarth 750GT Zagato with beyond primitive motor. Sometime ago, someone laughed and said that his lawnmower's got more horse power than that !

Thanx for the wealth of informations, Taz. w/ smiles Jimmy

[tazandjan]

Jimmy- I love Abarths and remember drooling over the 1300 Coupe with Simca based engine in my Observer's Book of Automobiles, Foreward by Stirling Moss, from 1963. Cost all of $1.25 and I still have it.

Number of Cylinders: 4
Capacity: 1288 cc
Compression Ratio: 10.4:1
BHP: 125 (talk about souped up for 1963)
Overall Length: 11 ft 8 in
Overall Width 4 ft 10 and 3/10 in (tiny)
Height: 3 ft 8 and 9/10" (~45", like a Dino 246GT but way earlier)
Wheelbase: 6 ft 10 and 9/32 in (1839 mm)
Fuel Tank Capacity: 6.6 Imp Gallons
Weight: 2397 lbs (sounds like that may be a bit high)

The book also contains the follow-on to your car with the 1000 Monomille Coupe and Balbero Coupe and mentions the 850 TC.

The Abarths were giant killers in just about all the major races in the 50s and 60s.

Taz
Terry Phillips

[viabono]

Jimmy...After you turn on the ignition with the key, do you pull one lever between the seats to start it and use the other lever for the choke?

[BarchettaGuy]

Thanks Terry,

This is great information. I look forward to learning more as I read through your wealth of information.

[Boxer]

Great information. As a drivers car, which of the two do you prefer (I have owned both a 550, and a manual 575 with FHP)?

[Jimmy Chen Shiba DDS]

Originally Posted by viabono

Jimmy...After you turn on the ignition with the key, do you pull one lever between the seats to start it and use the other lever for the choke?

No, viabono...that is not necessary. The car starts right up like a normal car. The previous owner has restored and placed short gear ratios for hillclimb use.
PS. I would luv to have a garage like yours in the Hollywood Hills, viabono. Great picture. My Abarth would be perfect for those hills there, but probably your neighbors would not appreciate the noise. For her size, she is loud.
PPS. Sorry the hijack.
w/ smiles Jimmy

[cribbj]

Originally Posted by tazandjan

John- Affirmative, I mentioned the 575M's digital throttle made for a much less intrusive ASR system. The 550 throttle cables are not directly connected to the butterflies, but actuate two potentiometers that control the opening of the butterflies and fuel mixture through the Motronic DMEs on each bank. The direct connection to the butterflies has been gone a long time. My Dino, Daytona, and 308 GTS had a direct connection to their Webers, but not these modern marvels of fuel injection.

Having flown aircraft (F-16) with no mechanical connections to any of the controls, I kind of like digital controls.

Taz
Terry Phillips

Sorry Taz, I did miss where you referred to the digital throttle on the 575 in the ASR section.

But on the 550, the accelerator pedal is definitely mechanically connected to the butterfly on the left side via a standard throttle cable, then there's another throttle cable that runs around the front of the engine that links the left side butterfly to the right one.

To confirm, I had someone press the accelerator pedal while I watched the throttles open/shut, and felt the throttle cable actuating them. This was with the ignition off, and I think on a DBW car without the ignition on, there won't be any throttle actuation.

Here's a couple pics of the 550 setup: first pic is taken from the top left side of the engine bay, and shows the throttle cable coming into the TB from the cabin. I'm guessing your 575 probably doesn't have this cable?

Second pic is from under the dash, and shows the accelerator pedal linkage. At the very bottom of the pic is the pedal's pivot point, then going up, there's the pedal position adjuster set screw, then finally in the center of the pic is the ball/socket connection of the throttle cable, and you can see where it goes up into the pedal box, and runs on that nylon pulley out to the TB. I think you probably have a potentiometer at the top of the pedal?

[tazandjan]

John- Looks like I got that one wrong. Thanks for the explanation.

The digital throttle works great and is necessary for the F1 system on the 575. The first F1 car, the F355, did not have it and did not have enough throttle authority to synchronize revs for up or downshifts. So they have F1 and still get to practice heel and toe (or right foot, left foot) downshifts.

Boxer- I have never driven a 550, so not much experience. I love the 575M and its F1 system. The high torque engine works really well with F1. My car has the Foorano Handling package and 9" F and 12.5" R wheels, so the car handles really well. Both the 550 and 575M are great daily drivers with lots of luggae space and excellent air conditioning systems, if properly maintained.

Taz
Terry Phillips

[bretm]

Another great thread. Thanks, Taz. Now I just need to figure out how to get a 550 or 575...

The 550/575 really is something special. I was lucky enough to be at Pebble Beach this past week for the concours. Carmel was littered with 355s/360s/430s, but I think the whole week I only saw one 550 and one 575 if I remember correctly.

[Steve2z]

Excellent post Taz! I am headed up to Ferrari of New England this weekend, they have a red 550 and a Nero 575- the 550 is manual, the 575 is F1- both the same price.....

[BarchettaGuy]

Originally Posted by Steve2z

Excellent post Taz! I am headed up to Ferrari of New England this weekend, they have a red 550 and a Nero 575- the 550 is manual, the 575 is F1- both the same price.....

Steve, why don't you see if they will give you a great deal if you take both of these cars off their inventory.......?

[tazandjan]

Steve, Bret- Good luck on finding one you like. As you discovered, Steve, the 550s and 575Ms are starting to overlap on price, as you would expect.

Taz
Terry Phillips

[JazzyO]

Thanks for the feedback on the production numbers, Terry!


Onno

[RDG]

Originally Posted by Steve2z

Excellent post Taz! I am headed up to Ferrari of New England this weekend, they have a red 550 and a Nero 575- the 550 is manual, the 575 is F1- both the same price.....

The 550 was the owners of FNE. Obviously very well cared for, fresh maintenance, 6 speed, and 4k miles.

[tazandjan]

RDG- Thanks for the info and welcome to FLife. Sounds like a really nice car. Start a thread in member introductions so we can get to know you better.

Taz
Terry Phillips