KW Coilover kit V3 ferrari 550/575

Is it not coilovers as standard on the 550? My 456 has that. Some nice ones made from bilstein.
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I think I have done the most engineering on the 550 suspension. My comments are not about your KW set-up but just the 550 suspension in general. My perspective is owning 2 550's both stock but one with my modified suspension. So the advantage is that I could drive them back to back vs. think I remember a certain handling quality if I only owned 1 car. Then I engineered a combination of Eibach springs, stock bars, and moton double adjustable shocks with custom shock valving. Finally, I'm a nationally licensed SCCA club racer and I took the Ferraris to the track to test suspensions under legal extremes in a safe controlled and repeatable environment on low level DOT race tires (Toyo R888's).

So my first comment on any 550 suspension modification is "be careful." Until you have run a suspension near the limits, on good tires, you have no idea what to expect. And what you think might happen may not.

Suspension is a compromise. It always has been and always will be. There is no perfect suspension set-up. Ferrari has its reasons for the suspension selection it has made. The factory compromises are extremely streetable for a fast GT car on poor Los Angeles roads. I find no advantage in changing the stock 550 suspension at even double the legal speed limits. If the 550 was to have some light track duty then go with the modified suspension. The biggest enemy of the 550 is not the suspension but both sprung and unsprung weight. The 550 is a pig with big pig feet. If you could drop some corner weight and 500lb out of the chassis you could give a 430 scud a run for it's money while the 550 would then have numbers and drivetrain layout closer to a C6Z06 which clearly is a match for the scud.

When I designed my 550 suspension I started by determining my goals which was to do light track duty in a car that could be driven to the track. I determined the corner weights, scaled the car, calculated motion ratios, leverage arms, chassis frequency etc etc. and obtained potential wheel rates then selecting empirical spring rates. All this data was giving to a respected race shock engineer to custom valve the moton shocks to be compatible. The outcome was exactly what I wanted. If I was looking for a full race set-up without added aero everything would change. If I added a wing and splitter everything would change again and each iteration would become less and less street friendly to the point of undriveability on the street. So...be careful...

 

Steve- I believe the Novitec 575M suspension package used KWs, so if they are the recommended ones for the 550/575, they should work fine. They should come with a shunt to prevent the suspension lamp from illuminating. Not sure how much stiffer the Novitec springs were, but those dampers should be an improvement over the stock Bilsteins, regardless of spring selection, and are adjustable to give you whatever ride/handling compromise you prefer.

 

I would be interested in hearing about how this "shunt" for the suspension light. And what you say makes sense but it is not often true. It can't work regardless of spring selection. The spring and shock work as a package with the chassis. If you mix springs with a random shock even a top adjustable brand you don't automatically have a good functioning package. The shock can only influence the "compromise" over a small range. A shock is for tuning not making up for things like not enough spring rate or to control porposing from improperly engineered chassis frequencys and spring selections. And those low level bilsteins are one of the few shocks that can be revalved for nearly any dyno curve and maintain good function during the rigors of racing never seen on the street. We proved that in corvette clubracing. Sometimes classy high brow shocks fail to deliver. I have seen classy triple adjustables leaking new out of the box or unable to hold remote canister nitrogen pressures . While the Name brand is nice, what is more important in a shock is its rebuildability and availability of parts to custom valve them by a good shock engineer.

 

So the KW's are probably just fine. The question is what are you buying? I hope no one take my statements as discouraging or disparaging. The hope was to inject a bit more technical into the discussion. You might be able to look at the KW spring rates then work backwards on to chassis frequency and get a feel for how far KW strayed from stock. And the dyno graph of the shocks can be telling.

 

FBB- Keep it up, you are doing great. The KWs and Motons appear to be the pick of the litter for aftermarket shocks. For me, FHP works fine with a late shock ECU, and the Sachs shocks are very sturdy. Would not mind a set of HGTC shocks at some point, since they improved the mounting system considerably over the early 575Ms, which were an improvement over the Bilstein mounts for street use. Not applicable to 550s, though. Too expensive to try the Sachs on a 550 and the aftermarkets are cheaper and likely superior on the 550.

Steve- Here is your 550 not ready to launch satellites and PhotoShopped mildly.

Ronny- Yup, OEM Bilsteins and Mannesmann-Sachs shocks on the 456s and Maranellos are coil-over.
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Can't wait to hear your impressions.

 

What were you trying to achieve? With an increase in rear spring rates (alone) you have taken out some understeer and, depending on how hard you went, may have a snappier more OS prone car. Is this what you want? Most don't.

Why do you think you have a shock problem rather than a spring or ARB issue? Does it pogo from being under damped?

I thought most of the (early) comments about the 550 suggested that when sprung with the FHP it was quite tight and too tight for many.

If you do go the shock route, Rob S will rebuild your 550 shocks, valving them as you want...but you have to be able to tell hiim what you want the car to do / not do...
Philip

 

FBB...

Very well said... My modified 550M race car with full roll cage dry weight right at 1400KG with custom made suspensions with ultra light weight components running Hoosier slicks right about the same laptime as my 360 Challenge racecar dry weight at 1150KG...

Alex

 

FBB, what were the stock ride frequencies and motion ratios for the 550? Do you have this data for any mid-engine models?

Best
Vig

 

Nope. I did the math and studies a long time ago. I can't remember and in all my clutter I'm sure I have the data somewhere but good luck finding it. It would be faster if I just did the math all over again. The hardest part was taking the suspension apart and weighing everything measuring arm lengths etc...

 

Steve- Looks good as long as you do not have any driveway clearance issues. That would scrape on my drive.

 

Steve,

Any further driving impressions? Where did you purchase the KW's from?

Best,

Derik

 

I have coilovers on my car. Not sure what brand they are. I can find out in a month when it goes in for service. It corners well, lots of wear on those front tires though.

 

Brad- They come equipped with coilovers from the factory.

 

Hmmmm, my mechanic told me that it was not the standard suspension. Perhaps it was changed during maintenance.

 

Brad- Talk to your mechanic and find out what you have. You can download 550 workshop manuals at ferraridatabase.com. Those aftermarket suspension set-ups are expensive. $8-9K plus installation, so nobody was doing that without you getting a huge bill. 550s use Bilstein coilovers and 575Ms use Mannesmann-Sachs coilovers.

 

Can you share your Moton data and the spring / bar rates you used ?

 

@tazandjan can you adjust the stock Bilstein shocks on a 550 WITHOUT removing them from the car? I am trying to un-do a bit too much lowering from a previous owner but the AD says they have to remove the shocks form the car to raise/lower the Bilsteins on a 550....... I swear that I have adjusted multiple F-cars over the years and never had to fully remove the shocks??!!

 

Affirmative, you can adjust ride height with shocks installed, but you need a spring compressor to take the load off the perches. You are not actually raising or lowering the shocks but changing the length of the springs while partially compressed. Too much compression of the springs and you can move the shocks outside their optimum operating range, which affects ride noticeably.