308 GTB Corner Weighting Data and Question. | Page 2 | FerrariChat
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308 GTB Corner Weighting Data and Question.

Discussion in 'Technical Q&A' started by pma1010, May 29, 2005.

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  1. speedmoore

    speedmoore Formula 3
    BANNED Professional Ferrari Technician

    Apr 15, 2003
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    D Moore
    #26 speedmoore, Jun 12, 2005
    That sucks! I made a "check sheet" for my guys. It's a common mistake. It' a lot of work to do one of these things right and when you are done, sometimes you just get in a hurry to finish up and forget........the check sheet works well...........if you use it.

    d
     
  2. speedmoore

    speedmoore Formula 3
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    #27 speedmoore, Jun 12, 2005
    Welcome to the school of hard knocks ;-)
     
  3. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
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    Philip
    #28 pma1010, Jun 12, 2005
    Fixed, David, thanks. Humped the weight and the dog food back in the car. Actually required a turn on the front and two turns on the rear drop link for a neutral bar.

    Yes, am a believer is taking notes. Check list is good idea. Will do.

    Again, thanks all for the help. Invaluable.
    Philip
     
  4. spang308

    spang308 Formula Junior

    Jul 17, 2004
    893
    York, PA
    #29 spang308, Jun 13, 2005
    Phillip,
    Ride heights look good and the car is statically balanced. Now that there is no preload in the bars, get that thing to the track.
    Take tire temps and some seat of the pants observations and get it dialed in.
    Your weights came out real nice!

    Good luck. You know how to reach me if you need any help.

    John
     
  5. pma1010

    pma1010 F1 Rookie

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    Philip
    #30 pma1010, Jun 13, 2005
    Have two days at the track next week as part of the Indy FCA event. Will let you know how it goes.

    Jeff Speer (of Hoosier) tells me the targets for the S04s are 40 to 44 psi. Will take temps.
    What would you look for as a typical spread outside -> inside and across the 4 corners?
    Philip
     
  6. spang308

    spang308 Formula Junior

    Jul 17, 2004
    893
    York, PA
    #31 spang308, Jun 13, 2005
    Even is the target, but you will probably see 25 degrees warmer on the insides. What cambers are you running and are the Hoosiers bias or radial?

    John
     
  7. pma1010

    pma1010 F1 Rookie

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    #32 pma1010, Jun 13, 2005
    I'll need to dig out precise alignment specs, but as I recall:
    front camber is neg 3.5, rear neg 2.2;
    Toe = 0 front, stock rear;
    castor stock (4 degrees)

    R3S04, Radial.
    Thanks, John
     
  8. pma1010

    pma1010 F1 Rookie

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    #33 pma1010, Jun 25, 2005
    Ran the car at IRP last week at the Nationals. Balance is neutral (stable, predictable, good u/steer o/steer balance) on the Yokos (A032R) and Hoosier "slicks" (R3S04).
    Thanks for everyone's help.
    Philip
     
  9. spang308

    spang308 Formula Junior

    Jul 17, 2004
    893
    York, PA
    #34 spang308, Jun 25, 2005
    NICE!
    How did all your other improvements perform?

    John
     
  10. pma1010

    pma1010 F1 Rookie

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    #35 pma1010, Jun 25, 2005
    John:
    I posted an update thread on the dry sump conversion: it performed flawlessly. 85 psi warm oil pressure all day long.

    The combined suspension changes (weighting, rake, larger ARBs) and Hoosiers were great. The car has a nice, predictable feel and showed no unpleasant behavior despite my mistakes.

    I am still wrestling a bit with jetting (44 DCNFs w/P6). Running 52 idles, 145 mains, 180 Air Correction jets and F24 E-tubes. Idles at 14.5:1. Even. Pulls about 5 kg/hr on all 8 throats. It is up to about 2000 - 3000 (the wideband says it is fine but it is popping through carbs, likely a false rich signal), very rich (10:1) in the midrange (4000 - 5000) and spot on (12.5 - 13:1) from about 5500 to 8000. I need an E-tube about half way between the F24 and the F36.

    Couple of people drove the car at the Nationals - including the senior FCA track instructor (who's a friend) and the senior tech from Continental (also a friend). Both were impressed with balance and 5500 rpm + performance.

    Some minor stuff to do now. Lower oil cooler line has slight seepage around the connection into the (new) cooler, oil pressure warning light sender has to be replaced.

    Again, thanks to you and the others for the help. Nice when it all works. Wouldn't work without the help from everyone involved and advice here.
    Philip
     
  11. ferrarifixer

    ferrarifixer F1 Veteran
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    #36 ferrarifixer, Jun 26, 2005
    This has been a good thread. I've little to add, other than a note for other 308/ stock ish car users out there.

    If you don't have adjustable ARB drop links you can shim the ARB chassis mount brackets with plates under one side to help obtain a more neutral bar.

    And the softer your springs, the less important cornerweighting is. A soft wallowy car will self level itself under dynamic loads, where a hard sprung racer will not.

    Every single change effects something else, however marginally, so you can chase circles all day if you choose. Tyre pressures must be set to your hot optimum, or even 5lbs over is a good option too.

    Ideally the steering should be locked with a central rack position, and verify the rack is mounted centrally, not just assume the steering wheel is straight.

    Finally, tyres and shock absorbers will give you vast wads of lap time, corner weighting is essential for a distance event/race, it makes braking much better, but over one lap it's not going to gain you a quantum leap, and is a huge sponge of man hours, so until you have the tyres and shocks sorted, don't sink endless man hours into it.
     
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