I prefer adjustable suspension F40's

I have seen so many posts about fixed suspension (FS) F40's being preferred over adjustable suspension (AS) cars, that I had to post my contrary views about the usefulness of this option, and maintenance of this simple system. I hope that other owners of AS cars will support me here with their posts.

It is true that many car brokers, and some service organizations have influenced buyers to prefer FS F40's, but this discrimination is undeserved. This discrimination occurs because these people do not know how to maintain this simple AS system.

The AS system was only offered as an option in later cars from 1991 onwards, although a retrofit kit was offered also.

The advantages of the AS system are that there are 3 ride heights - high (obstacle clearance), normal, and low (race track mode). In addition, the AS cars are self leveling, adjusting for fuel load, and passenger weight. The FS cars only have one ride height and are not self leveling.

I have extensively driven both AS and FS cars, on road and track. In normal road driving I need the higher suspension setting for some gutters, driveways, big speed humps etc, even driving at an angle over obstacles. The F40 is not that low to the ground, but the front has a lot of overhang which can create the ground clearance problem. It is said that the F40 front spoiler is sacrificial, and is easily replaced, but I am still on to my original front spoiler with AS.

The AS system is so simple. An electric pump, a hydraulic reservoir, 8 electro magnetic valves controlling hydraulic fluid going into or out of each suspension strut. This is all controlled by one ECU that sits near the brake and clutch master cylinders. Additionally there are 2 rheostats that relay front and rear suspension height information to the ECU. The ECU has a car speed input. There are 2 accumulators and some pipes. The whole system weighs maybe 5 kg.

I believe the main problem that caused the bad reputation in the early days, is that if the car was not used for a long time, the system would depressurize, the ultra low position of the car would trigger an error message in the ECU, which was memorized, disabling the AS system and triggering an orange warning light on the dashboard. The Ferrari factory published a simple fix for this which TOTALLY FIXED the problem. A simple 2 wire switch fitted under the dash clears the memory. 15 minutes to fit.

The system is very reliable, but other components can also go wrong. All the electro magnetic valves have rubber "O" rings, which go hard in a 25 year old car, and I replaced all of these (easily) so the system holds hydraulic pressure much longer. A friend had his AS ECU develop a fault. He took it to a place that repairs ECU's from mass produced cars, and had it fixed for $200.

Some friends have commented when the car lifts slightly at traffic lights. To prevent the car from hunting up and down continually while driving, the ECU only self levels when the car speed is below 20 kph for 10 seconds. The high position automatically drops to normal when the speed is above 25 kph. The height automatically goes to low when the speed is above 100 kph

That's really all there is. There isn't anything else.

I hope that all those people who influence buyers to prefer the more numerous FS F40's, will
start to tell people that there are owners who prefer or need AS F40's, and maintenance people spend a bit more understanding how straight forward fixing faults can be.

I prefer my adjustable suspension F40.

PS. If someone buys an AS F40, and decides that he doesn't like the AS (for whatever reason), it is a simple matter of changing the 4 shock absorbers for standard ones. The rest of the suspension is identical in both models.

 

The exact ride height numbers would have to be looked up in the F40 service manual.

I believe that now that F40's are so collectable, any non factory non original modifications
are detrimental to the value and desirability of the cars.

Regarding ride height needed, it depends on where you drive. Many people can drive on normal roads, including ordinary speed humps, with a fixed suspension F40. I and some others need the extra height of adjustable suspension to navigate some gutters and driveways. If you need even higher suspension settings, you must have particularly difficult terrain to travel over.

 

The F40 was designed for adjustable suspension from the beginning. But AS was not ready at the time the cars were first released. So all F40's have holes drilled in the frame to run the hydraulic pipes (well Eurospec - I don't know about the US spec version). That is why a retrofit kit was available.

 

Another argument for AS F40 is that that the adjustable suspension is rarer, and therefore if you follow the trend with other Ferrari cars, or other exotics, should be more desirable.

 

So you had a fixed suspension F40, and felt that you needed lifting suspension?
Is that correct? I am making the point that some people need lifting suspension
to drive in their area.

Then there is the question if you stay original or not. I think you are making the point that for you drive-ability is more important than resale considerations, which is OK also.
Everyone to his own.