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360 steering vagueness

Discussion in 'Technical Q&A' started by vanimal, Feb 23, 2004.

  1. vanimal

    vanimal Formula Junior

    Mar 19, 2003
    380
    UK
    Full Name:
    Vaughan
    Any advise or insight appreciated on this would be appricated. Having had my 360 coupe now for around a month and having covered about 800 miles I am not sure all is well on the steering front, my reasons are based on the feeling and experience from my old 348 challenge, here is what is on my mind -
    ~ When driving on a smooth motorway the steering feel is very vague and only seems to respond once you put in enough input to turn the car to change lanes, with the 348 the slightest input the car responded, it was alive and did not feel asleep or dead and also tracked straight as a rod.
    ~ When driving on uneven or rutted motorways the 360 tramlines like crazy, its constantly fighting you and takes constant input to keep straight, again the 348 also had this tendency but not as apparent.
    ~ on back roads its entertaining to say the least but so was the 348

    So what I am probably getting at is the lack of feel and tendency to wander at moderate (60-80mph) speeds on motorways. Once your at higher speeds or loaded up in a corner she is fine.

    The 360 is running on Michelin Pilot sports and the 348 C was on P-Zero's (tyre pressures are fine)

    Should I get the allignement checked or are 360 just this way???

    Your thoughts and advise appreciated.
     
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  3. jeff

    jeff Formula 3

    Feb 19, 2001
    1,924
    North America
    I would have the car's steering checked. I've had 2 360s and the steering is not like you are describing. The 360's steering is similar to your 348 Challenge. The 360 steering will respond to the slightest input.
     
  4. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    I'll second that... there is nothing vague about the steering of a 360... get it checked out.
     
  5. dan360

    dan360 F1 Rookie

    Feb 18, 2003
    2,669
    Boston
    Front suspension ball-joint problmes are a 360 occasional occurence - this leads to some slop around center in the steering rather than the to be expected very direct response.

    Most likely this is your problem - did you drive in a big pothole?
     
  6. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,058
    At best you have a tire pressure issue
    Or you could have a tire wear issue
    Or you could have a suspension alignment issue
    Or there could be some part that is not right in the suspension

    Check tire pressures and equalize left/right (0.5 PSI matters in these cars) Use an accurate guage.
    Check thread depth at 3 points across each tire with an accuracy of 0.02". If the tires have not worn evenly, they could be the culpret. In additioin, you cannot align a car with uneven tire wear.
    If neither is a visible culpret, have the car looked over for alignment, corner weighting, and suspension point wear.
     
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  8. forzarich

    forzarich Karting

    Nov 11, 2003
    90
    Dorset, UK
    Is it an F1 car?

    I have exactly the same as what you are describing. I too am running very nearly new pilot sports.
    I also had issues when changing gear when accelerating moderately quickly. It would wander in an almost torque steer manner, I had no confidence in the car when driving hard.

    it went back to the dealer and track rod ends were replaced, it's a lot better but not perfect and I wonder now whether the tyres are the culprits...

    Rich
     
  9. vanimal

    vanimal Formula Junior

    Mar 19, 2003
    380
    UK
    Full Name:
    Vaughan
    Guys thanks for the replies so far, the car is not F1, but really not anywhere as good to steer as the 348 was. When the car went in for its MOT (uk roadworthy annual check) the technician did have a good look at the front suspension conponents for me and gave it the all clear. From the service history some rod end components wer replaced some time ago. I forgot to mention that the steering wheel is off-centre when in the straight ahead driving position, this leads me to believe its alignment problems.

    Will let you know once its been looked at.

    Vaughan
     
  10. paulie_b

    paulie_b F1 Veteran
    Consultant Owner

    Jan 13, 2003
    6,792
    Jupiter, FL
    Full Name:
    Paul Bianco
    I triple the comment above by Jeff and Brian. No problem with mine.
    Check alignment, tire pressure....?
     
  11. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    Parallel tracking or toe out on the front causes tram lining or straight line instability. Added to the road car near zero negative camber, this makes a vague set up.

    To help you picture what happens.....each front wheel is actually trying to pull the car slightly to it's own side, and so, as weight transfers from wheel to wheel on bumps and undulations, the car will try to go where the loaded wheel is pointing. So, if the loaded wheel is pointing INTO (toe in) the centreline of the car, it will improve it's feel and stability. If the loaded wheel is pointing AWAY (toe out) from the centreline, it will try to pull the car further that way, amplifying the instability or vagueness. All this applies generally and up to a certain point.

    Just 1mm each side (2mm total) toe in on the front will make it sweeter.

    But get a full 4 wheel alignment job done. The rear end could be out too.

    If you plan on going to the track ever, or like to push hard around roundabouts or corners you'll benefit from adding negative camber.

    Check the archives on set ups, but run to the maximum tolerances on toe in and negative camber given a choice.
     
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  13. stevep

    stevep F1 Veteran

    Jan 19, 2004
    8,330
    Geordie Land
    Full Name:
    steve
    forzarich/vananimal, did you get this sorted....if so what was the issue/issues?
     
  14. fatbillybob

    fatbillybob F1 World Champ
    Consultant Owner

    Aug 10, 2002
    19,166
    socal
    couple comments...1) the 348 is a manual steering box and rp. The 355 and 360 are power units right? Many used to complain about the 355's for the vagueness vs the 348's. 2) the a-arms on the 360 are short or something like that...making for alignment specs needing to be dead on. Many alignment shops are quite lazy and turn your car in a few minutes. The last weighting/alignment I had took 4 hours and I sat it the car when it was being done! Now services like that really make a difference. 3) if the tires are strangly worn but still have meat you can have them shaved. You will loose miles but gain perfectly flat round tires totally dialed in for your wheel. They will check balanced too. sometimes you loose the tape weights. If you find that these problems are still there after all this assuming mechanicals are o.k., you can then talk your alignment guy into setting up the car for your driving style by messing with front rear toe/camber/caster etc... but use a race shop or a raceshop reccommended alignment guy. The standard alignment guy can't do it.
     
  15. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,058
    Correct
    The alignment specs on all modern Ferraris include a check and a reset of the ride height.
    Do yourself a favor and do NOT have a Ferrari aligned on tires that do not have exactly the same rolling radius side to side (e.g. don't align on worn tires).

     

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