355 348 Manual Rack in F355

Has anyone done this swap? Seems like an easier option versus finding an unobtanium Fiorano rack.

 

Is the F355 2.7 manual rack also unobtanium?

https://www.eurospares.co.uk/parts/ferrari/355-27-motronic/suspension-steering/mechanical-steering-box-40993

Judging by the price (compared to the 348 racks), I guess the prices haven't been amended recently.

I assume that this rack fits the 5.2 as well, as the 2.7 and 5.2 power steering racks have the same part number. Of course, you'd still need someone to tell you how the car drives (steering ratios, etc).

The mounting system appears to be different to the power rack car's, as is the firewall boot.

 

I was more thinking how much easier sourcing and rebuilding (if necessary) a used 348 rack would be. I wonder if it would drop right into a 355? Paging @ShineKen for some in-depth analysis

 

I drove a 348 for the first time last week and honestly I’m not sure I like the steering better mostly because it felt slower (and too slow) compared to my 355 rack.

You might want to try driving a 348 before going down this path.

 

Just of curiosity how did the rest of the car compare? I’ve heard the steering is a big takeaway from the 348 compared to 355

 

There are a ton of differences. Shifter, steering, power, throttle response etc. all different. I like the 348 but I'm partial to the 355.

 

F355 manual rack is unobtanium. Not much feedback from those who have it either, which I think is very few.


I think it is easier to modify an existing 355 rack to manual.

 

I've driven 964's and 993's with manual racks and they're awful. You're driving from the torso and shoulders. Power steering is much, much better in every way. There's a reason those cars had PS and I'm sure there's a reason the 355 does as well.

 

Not my experience at all. once you roll even an inch the steering is light. Yes standing still cranking the wheel is a pain but just roll a hair and that goes away. At any driving speed steering is hardly what one would describe as a chore. Many modern electric racks reduce or turn off boost once underway.

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I will say that going to the F50 wheel made a significant difference in steering weight and feel. It must be quite a bit smaller than stock.

 

When considering 348 v 355 purchase years back, I concluded that I like everything more on the 355 except for the steering. I ended up buying a 355 Ch, which now has manual steering. I wouldn’t go back to ps in my 355 Ch. The feedback is even better than my favorite manual steering ac early 911s and Formula Fords. The feel and effort are so much more in sync the rest of the car IMHO. And as previously mentioned, the steering effort lightens up with just a slight roll (I have the small diameter period Challenge-spec Momo steering wheel).

 

Meaning you purchased an early 355 manual steering rack and put it in? What came off the challenge car? Quick steering rack or standard rack?

 

would love to hear more as well!

 

After researching 348/355 racks and consulting with race mechanic who has worked on Challenge cars, I elected to do manual conversion of in-situ ps rack. Besides, I can more easily revert back to ps if I didn’t like it. 3 years later, ps bits are still neatly stored in parts shelf.

Re: quick or standard rack, I understand that stock 355 is 3.25 lock-to-lock. Is this correct? Mine is 2.75.

 

Oh, I’d like to point out that Challenge cars are significantly lighter and may have different alignment setup than 355s. I have not tried manual steering on full street 355s.

Even though I run wide Trofeo Rs/slicks and small dia Momo Steering wheel (both of which may add to steering effort), 2700 lbs and > -2.5 negative camber may help reduce steering effort and initial turn-in.

 

And there you have it folks… Modify existing rack to manual (as I recommended). He also retained quick steering ratio as he has a challenge rack.


We don’t know if the early manual rack was quick steering ratio or not. Moot at this stage as it’s unobtanium.


I feel we’re still going to circle back to my initial proposal of buying the challenge rack from Japan and replicating it OR have Quaife build a rack and pinion for us to spec. Then you can choose if you want manual or not.

 

For the in-vehicle rack, is it a matter of capping the lines and remove the PS-related components if so chosen?

 

I just put my hands on a 355 manual rack. Will post pics. It was leaned up in the corner of a friend's shop, he's happy to sell it

 

Here it is....DM me if you want it, happy to put you in touch with the seller.
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I believe so.

 

Wow. It looks very similar to the one on the 348 although they have different part numbers. Could be the same steering rack with a different ratio than the one on the 348.

Anyone have pics of a 348 rack?

 

The part number for an early 355 manual rack is 157544.

 

Here's 348 manual rack.

https://www.ferrariparts.co.uk/part/ferrari/155566?id=35652

 

Would love to see what comes of this..

 

Bump to see current opinions on improving stock F355 steering feel....

I've got a U.S. F355B built in Oct. 94.

While I love just about everything, the loose, over-assisted steering feel is a definite drawback.

What remedies exist and at what cost (parts + labor) ?