Reducing steering assist? (355) | FerrariChat

Reducing steering assist? (355)

Discussion in '348/355' started by roadracer311, Sep 22, 2011.

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  1. roadracer311

    roadracer311 Formula 3

    May 6, 2009
    2,398
    San Francisco
    Full Name:
    Paul
    I'm not really thinking of taking this project on, but I'm curious if anyone has reduced the amount of power assist on their 355. I would think there must be a pressure regulator for the power steering and that by reducing the pressure, the amount of assist would be reduced and give more feel. I love the over all handling of the 355, but the steering feels too light to me.

    Something else I stumbled across today on Ricambi's site, is a non-boost steering rack. The price seems right $414 or $966 depending on which version "GD" or non "GD" whatever GD means.

    Drawing here:
    http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=1386
     
  2. jmnov

    jmnov Karting

    Mar 15, 2009
    163
    Lausanne
    If I knew how to do I would do it immediately!
    From what I've heard even on the F355 Challenge the steering feel is the same, only the ratio is lower down to 2.5 instead of 2.75...
    With all the mods I did on the chassis it is really the worst point left on my car...
     
  3. Aircon

    Aircon Ten Time F1 World Champ
    BANNED

    Jun 23, 2003
    100,524
    Melbourne, Australia
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    Peter
    You are correct. Still too light and little feel.
     
  4. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    9,742
    Put a smaller pulley on the PS pump. This might require a shorter belt at the same time.

    Alternately: make a couple of hoses with fittings appropriate to the PS threads. Connect the PS pump to itself (in to out), wire the PS runs to the steering box to themselves. Presto, no PS.
     
  5. plugzit

    plugzit F1 Veteran
    Silver Subscribed

    Dec 1, 2004
    7,792
    Redondo Beach, CA
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    Bruce Bogart
    Wouldn't you put a larger pulley on the pump to slow it down?
     
  6. bcwawright

    bcwawright F1 Veteran

    Jul 8, 2006
    5,234
    Georgia
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    Bruce
    That is how it's done in Zimbabwe
     
  7. plugzit

    plugzit F1 Veteran
    Silver Subscribed

    Dec 1, 2004
    7,792
    Redondo Beach, CA
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    Bruce Bogart
    So....you're saying that's the Zimbabwe way?

    Then it follows that if James Robert did it, it would be JimBob's Zimbabwe way?
     
  8. bcwawright

    bcwawright F1 Veteran

    Jul 8, 2006
    5,234
    Georgia
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    Bruce
    Me thinks we have waaaay to much free time on our hands.....u go sell a house and I'll finish deconstructing my F car.
     
  9. roadracer311

    roadracer311 Formula 3

    May 6, 2009
    2,398
    San Francisco
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    Paul
    Nice! Way easier than fitting another rack.

    I *was* surprised to see the drawing of a completely non-power-steering-assisted rack on the Ricambi site though. If it's not for the challenge cars, I wonder what it's for. Maybe Daniel knows.
     
  10. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    9,742
    Larger pulley on pump slows pump down,
    Smaller pulley on drive slows pump down.
     
  11. saw1998

    saw1998 F1 Veteran

    Jun 8, 2008
    8,237
    San Antonio, Texas
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    Scott
    #11 saw1998, Sep 24, 2011
    Last edited: Sep 24, 2011
    It was possible to order the F355 without power steering.

    The Fiorano Handling Package (available only in Europe) used the aforementioned PS pump ratio and a different ratio rack. The 1999 Fiorano edition F355s had this package installed. You can purchase both of these parts, but they are very expensive. I'd have to really test the car to ascertain the difference before spending that kind of money.

    GD = Right-hand drive cars. BTW, this find of the non-assisted rack was GREAT. I also would love to install this into my car. If we get rid of our PS, we could become "Manly Men" like the 348 owners and our biceps and forearms would become huge. :)
     
  12. F355Bob

    F355Bob Formula 3

    I thought the Fiorano package had the challenge rack and pump? Are you saying it had a non power steering rack?
     
  13. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,272
    socal
    I felt the same way about the assist in my C5Z06 racecar. So I got a smaller diameter steering wheel and that decreased the felt assist and gave me more clearance ingress/egress and give me more control at 3 o'clock 9 o'clock for making quick steering corrections.
     
  14. saw1998

    saw1998 F1 Veteran

    Jun 8, 2008
    8,237
    San Antonio, Texas
    Full Name:
    Scott
    No sorry, I was not clear. The European Fiorano HP and the U.S. Fiorano F355 edition used the Challenge pump and rack. The FHP also used the Challenge steering rack mounts and the front and rear sway bars & mounts. It's really too bad the FHP was not offered in the U.S. I wonder why? Probably, the same litigation-based reason why we also didn't get the ABS cut-off switch.
     
  15. F355Bob

    F355Bob Formula 3

    Wondering if you could put in the challenge rack and as Mitch said to loop the lines to get rid of the hydraulic. This would give you no assist and a fast rack. Has anybody put a in line valve to decrease the amount of fluid going to the rack? Would this give you some power steering with a a better feel?
     
  16. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,272
    socal
    Just buy a 348
     
  17. roadracer311

    roadracer311 Formula 3

    May 6, 2009
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    Paul
    I would guess that the power steering system has some sort of a pop-off valve to regulate the pressure in the system. Seems like this would be the best way to reduce the boost. Using a smaller pulley sounds like a good idea as well, but then you're going to get a lot of variation in assist depending on RPM, until the system hits the maximum allowed pressure.

    I think installing the non-power-assist rack would give the car much better feel. Who knows what ratio it has.
     
  18. spaghetti_jet

    spaghetti_jet Formula Junior

    Jan 5, 2005
    949
    Europa
    Full Name:
    Bob
    When I first got my 355 back in 2003 it came "fully serviced" prior to delivery. The job they did was shoddy and among other minor issues there was a pipe clip chafing on the PAS drive belt. A few months in the belt shredded about 150KM from home. Once I'd established that the belt was the only issue I decided to drive home without power steering. The steering was surprisingly light when moving. Not too much difference I'd say compared to normal, although I didn't do any heavy cornering so can't speak for steering loading up when heavily cornering. Obviously I was taking it easy. The biggest issue was at parking speeds which required brute force on the steering wheel to park.

    My experience is that there is not a lot of power assistance when actually moving so if you really wanted to change the feel of the steering I would say to install the challenge or fiorano parts since mechanically/gearing-wise the feel is still quite light when on the move.
     
    ShineKen likes this.
  19. F355Bob

    F355Bob Formula 3

    I still am not clear as to how much the challenge rack changes the steering feel and steering quickness. I have a brand new challenge rack that I have had for two years and have not installed yet because I wonder how much difference it will be over stock. The pump is installed but not the rack. No one seems to know what the ratio is. A quarter less turn lock to lock does not seem like much. Who has driven one with the challenge rack?
     
    ShineKen likes this.

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