550 FHP Reproduction Package?

Here is what is on the 550 FHP. No shocks. Having springs wound and an anti-roll bar made is relatively simple and one owner had FHP springs made.
Image Unavailable, Please Login

 

I had springs custom wound. About $100-120 per corner. Any race shop could fab an ARB for a couple of hundred dollars. The F ones if you can get are silly money.
Philip

 

Philip- I was trying to remember who had that done. Yours looked just like OEM.

We should talk to Daniel about doing a kit, or Paul Hill. Would be a money maker for just the springs and anti-roll bar at $1500 or less.

 

No controversy, we have the complete specs for the FHP springs and relative stiffness of HGTC and FHP from Ferrari, but no HGTC spring specs, even in the last WSM from 2006. The FHP spring specs are in the 575M Technical Thread. Stiffness compared to OEM below:

HGTC

Front Springs: 35% Stiffer
Rear Springs: 15% Stiffer
19.5 mm Rear Anti-Roll Bar: 73% Stiffer

FHP

Front Springs: 32% Stiffer
Rear Springs: 12.5% Stiffer
21 mm Rear Anti-Roll Bar: 133% Stiffer

 

Yes, FHP in the 575M Technical Thread. But not for HGTC.

 

I am sure my race shop could do a bar. PM me and I'll provide contact details.

 

Make the bars adjustable I'd be in for 1-2 sets.

Call me crazy but I have 2 550's and the steering is different on both. Both have the Maranello Skunkworks switchable steering ECU's. I actually like the super light steering for the track because power steering is power steering it may as well be light precise and not tire you out. If it was manual rack and pinion that's a different story. Racing is hard work. Light steering is an advantage as is a butter light clutch.

 

We're looking at doing an FHP package, minus the suspension ECU. We've had a EE with a wealth of embedded experience (obviously not me ) working on the suspension ECU, but we haven't cracked it yet.

We do have a proposal for a 22mm hollow bar, which the (highly regarded) manufacturer says provides the same rigidity, etc. as a 21mm solid, and would be adjustable (just for you Carl ).

We understand there have been issues with other sway bar reverse engineering attempts on other subforums here, so we're not using that manufacturer, nor will we offer these until they've been proven to fit and work on our own cars.

This package hasn't been a high priority for us, but if there's real interest, we can give it a bump in priority.

 

John- Since all the components except the 550 shock ECU work on 550s and 575Ms, seems like there would be a market. Springs should be easy and Philip and FBB have already done that.

A 22 mm hollow bar as stiff as a solid 21 mm bar? Not sure that passes my "that looks about right" (TLAR) test. Easy to calculate once you get some details. 4th power function IIRC.

 

Dave- I guess it depends on how thick the outer layer is. Have to do some research. Most suspension torsion bars were solid, but my old 356A had hollow torsion bars, so sounds like you are correct. I thought the hollow bars were much larger in diameter, though, but lighter in weight, for the same stiffness. They were relatively large on the 356A.

 

Terry,

See this: http://www.whiteline.com.au/docs/bulletins/Hollow%20vs%20Solid%20Swaybar.pdf

 

John, sounds like you have it covered.
Philip

 

Yes, A hollow bar with a slight increase in OD can have the same torsional rigidity as a solid bar of the same modulus of elasticity but with significant weight reduction at a certain wall thickness.

Think of it this way. When a bar is twisted the center doesn't move, the further out you get from the center the more relative movement you get. Therefore removing the center and adding a small amount to the OD can give the same torsional rigidity as a solid bar but will be much lighter.

Here's the math.
Image Unavailable, Please Login

 

Here are the calcs to find an equivalent hollow bar to a solid. They assume that the ends have been treated properly:
Image Unavailable, Please Login

 

I'm in for a kit if this comes to fruition.

Derik

 

John- All the math looks good. I had previously used the same equations to calculate the relative differences in stiffness between the 17 mm, 19.5 mm and 21 mm anti-roll bars, but that simplified down to ratios of the 4th powers of the diameters.

I did not realize a hollow tube saved that much weight.

 

me too.

 

If it turns out that my 575M doesn't have the FHP (which I am going to check when I take it out of winter storage in the Spring), then I would most probably be in for a kit as well

Clyde

 

In case anyone is keeping track, I'd also consider joining in for a kit for my 2004 575M.