355 challenge rack

More than that, Tim, a Challenge car is just not safe on the streets. Taking a corner on an uneven road surface can upset the car badly.

Read Rob Shermerhorn's aticle on his Delta Vee website: Chassis Tuning Ferraris for the Racetrack


Why are Ferrari’s so “soft”?

This term is relative, IMO. Ferrari’s are no softer than most other road going cars, even other sporting automobiles. Suspension design is all about compromise with a road car. The environments change, the market is worldwide. Ferrari determined that this is the best solution, and I agree. Most Ferrari’s are comfortable, even on long drives (and I’ve driven them cross-country), and sporting enough to be better in many ways than the competition. Ferrari improves on the average sporting car with a bit more suspension damping. As an owner, overall you are satisfied. But this compromise in design opens the door for improvements if you (the owner/driver) have interests outside Ferrari’s average design parameters, like track events or actual competition on the racetrack.

For reference, the front wheel rate of a F355 Challenge car is 1,078 LBf/in with a 2200 LBf/in spring! This is very uncomfortable on the street, plus this system utilizes a tender spring to take up slack when the suspension goes full droop, and comes crashing down on this tender spring with every slight roadway undulation. But, the on-track race car’s vehicle dynamics are superior to the road car’s.

The F355 Challenge factory settings confirm that the factory knows increasing front roll stiffness increases grip and drivability on the racetrack with race tires.

So now we are into changing springs, and increasing spring rates involves increasing damper (shocks) forces. Here is where consulting with an experienced team or engineer will pay off by shortening or eliminating your development time.

Feel free to email me with details of your goals for your project.

 

I would speak to Rob Schermerhorn at Delta Vee and let him advise you how to best set up your car for what you intend to do with it.

Delta Vee

 

Great advice, FBB.

I wonder if the F355 steering racks can be modified to quicken the steering. We were lucky to get Maranello Skunkworks' switchable power steering ECU module for our 550s.

Barry

 

I remember way back when in the 80-s or 90's Jackie Stewart was doing some tuning on the ford mustang and went with softer bushings / smaller sway bars just because the car would break loose too fast and not recoverable in wet conditions.
Much finer line with these rear engine cars. I just bite my lip and shut up when I here people doing some things that make no real sense.

 

Right, Tim. A car breaking loose too fast is not a pleasant experience. And it can happen in dry conditions too.

Quickening the steering a bit and reducing power assist with a Challenge rack and pump is pretty benign. Improvements outside the stock F355's stock suspension design requires careful consultation with those who are qualified in the field.

Challenge parts do not make a better F355, but they do make the F355 a better track car.

 

Barry,

What is your 355C like to track in the rain?

 

Carl,

I've been taught how to properly track the F355 Challenge in the rain. A few years ago, it rained lightly all day long at Watkins Glen. I had my techs take off the slicks and mount my speedlines with Hankook ventus V12 evos on them. Then I found an instructor I had worked with previously and had him teach me what to do. We went out on every session and I learned to drive where the track wasn't shiny, how to do rimshot turns and off-line and late-apex turns. Little-by-little over the course of the day, I saw my lap times improve. He carefully taught me what to do in the rain without a single incident. At subsequent track events, even at Lime Rock, NJMP Lightning and Daytona, when it rained I never hesitated to take the car out on the track.

The F355 Challenge with rain tires, and driven carefully, is a nice predictable car to track in the rain.

Barry

 

Curious. I would think you would understeer like crazy. You have lots of guts to learn rain line at WGI. A mistake there means you hit the armco.

 

You know, the rain line changed with each lap at WGI that day. I just stayed on the dull parts of the straights, braked earlier and lighter for the turns which I took at reduced speeds. I stayed off painted surfaces and crossed over the concrete strips where I could (this was before the track was repaved a couple of years ago).

I was a new Blue Run Group driver at the time and I asked the instructor if I was ready to do it. He said he would suit up and be right over. We had all day for me to learn the exercises. By 5:00 PM I felt like I had driven three track days! The instructor being willing to get in the car with me did much for my confidence.