400i Spring Change | Page 2 | FerrariChat

400i Spring Change

Discussion in '365 GT4 2+2/400/412' started by Indy430, Aug 14, 2013.

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  1. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    31,633
    MA
    Full Name:
    John
    If that is true, you had better count your cylinders Christian to make sure that you have 12 instead of 8! ;)
     
  2. aidanparte

    aidanparte Formula 3

    Jul 18, 2004
    1,222
    Having driven Christian's 400 recently, I can assure you it is running on 12!
     
  3. GT Jones

    GT Jones Formula Junior

    Oct 15, 2011
    669
    Lincoln, MA
    Full Name:
    Christian J
    Running so well that I took it apart. again.
     
  4. GT Jones

    GT Jones Formula Junior

    Oct 15, 2011
    669
    Lincoln, MA
    Full Name:
    Christian J
    #29 GT Jones, Oct 18, 2013
    Last edited by a moderator: Sep 7, 2017
    I went to see the good folks at KTR engineering in Ayer MA. They had a device to measure the spring rate and found the fronts (likely original) to be 275 lb/in and these oddball green springs were only 100 lbs/in! No wonder the car felt fat & sloppy. I have to believe that a shop subbed these in for some weird reason. Somewhere theres a fiat 131 sedan missing its coils. I'm going to stiffen things up considerably.
    Image Unavailable, Please Login
     
  5. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
    2,169
    Tampa bay
    Full Name:
    Bruce
    lol :D lol
     
  6. Lindberg.75

    Lindberg.75 Rookie

    Jul 4, 2016
    5
    Sweden
    Full Name:
    Jonas Lindberg
    Hi GT Jones!
    I am restoring my 400 and wondering if you came to any good conclusion regarding the springs to the rear suspension.

    Best Regards from Sweden!
     
  7. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    The shop manual on page F24 gives the spring rate of 0.555 mm / da N. I bet someone in Sweden can tell you what that means. It also gives free length of 426 mm and length at static load of 241 mm with a static load of "da N 300". Do a little math:
    426 - 241 mm = 7.28 in.
    if 300 N is 300kg = 660 lb
    660 / 7.28 = 91 lbs / in. pretty close to 100.

    Alternate: 0.555 mm / N can be expressed as 1 /0.555 = 1.8 kg / mm with a little conversion = 100 lb / in exactly.

    Remember we have 4 springs, so rate per side is double.
    I put my engineer hat on.
    Ken
     
    Schumi and Arvid like this.
  8. Ak Jim

    Ak Jim F1 Veteran
    Owner Rossa Subscribed

    Dec 23, 2007
    8,451
    North Pole AK
    Also the spring geometry can make a big difference. On the 365/400 the springs are vertical and also the springs are attached to the A arms out at the very end. I was changing a front hub on my van today and happened to notice the spring is attached about 1/2 way out on the A arm which would require a stronger spring then if it was farther out.
     
  9. GT Jones

    GT Jones Formula Junior

    Oct 15, 2011
    669
    Lincoln, MA
    Full Name:
    Christian J
    I now believe that 100 was accurate for the stock spring. Unfortunately I can’t find the notes from a few years ago because I thought I had found proof that the self levelers were effectively 100lb springs too. I have Koni coil overs that replaced the self-leveling shocks and am using qa1 130lb springs. The ride is firm and more accurate and there is a lot of rubber in these cars to soak up vibration. My front springs are also slightly uprated eibachs at 300lbs.
     
  10. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    It makes sense to increase the rear spring rate when eliminating the hydraulic system. The hydraulics actually raises the car and adds to the spring rate.

    As for raising the front spring rate that is a personal preference and I would not; I find my car pretty rough on bumps already in the front.
    Ken
     
  11. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
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    Patrick
    I have the Koni coil-over conversion - didn't measure the spring rate, but the car still felt a bit low, so put in 20mm spacers - looks/feels about right now
     
  12. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
    Full Name:
    Patrick
  13. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    the 365 sure looks high in the front!
     
  14. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
    Full Name:
    Patrick
    Not a well loved example - it looks low in the back to me. The 17's on the 400 fill the guards better than the 15's on the 365. The centre caps were off because I just put new tyres on it.
     
  15. simon klein

    simon klein Two Time F1 World Champ
    Owner Silver Subscribed

    Feb 25, 2009
    28,802
    North Qld
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    simon klein
    Yeah well thanx for that Pat.
    As a matter of fact it IS well loved,particularly mechanically,as far as it's other general patina,it's had an $11K paint about 5 years ago,front seats releathered...properly.
    The rest of it is generally how it was when I bought it 11 years ago....crappy mousehair,crappy carpet.
    The car doesn't have books or tools but has most of it's history on the club register or with the car.
    Next time you feel like bagging someones car can you NOT do it on the public domain.Thanx.
     
  16. simon klein

    simon klein Two Time F1 World Champ
    Owner Silver Subscribed

    Feb 25, 2009
    28,802
    North Qld
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    simon klein
    No it's not,it's fine,thanx.
     
  17. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
    Full Name:
    Patrick
    FFS Simon, I didn't mention anything about who the owner was, and you've gone and outed yourself! Yes, you do attend to all the mechanical needs of your cars, but (and I've mentioned this before), you need to tinker with them and tidy up all the minutiae that comes with owning cars of this vintage, and you can't do that when you have them stored nearly 2,000 km away. Bring it up to your home, drive it around a bit, and that way all the little problems will show up and can be attended to in good time before you end up blowing your muffler off in the middle of nowhere!!!
     
  18. simon klein

    simon klein Two Time F1 World Champ
    Owner Silver Subscribed

    Feb 25, 2009
    28,802
    North Qld
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    simon klein
    When you originally posted that pic,earlier this year prior to the GAD, my ownership was recognised at the time....and the spring discussion was there as well

    Re the muffler,you'd best talk to our auto electrician before YOU put foot in mouth.

    Re the remainder,that car stays down there 'cos the roads up here are worse than the one's we took out our front undertrays on on the GAD!.
     
  19. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
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    Patrick
    Yeah, well, I guess a forensic examination of past posts may have revealed that - my apologies. I have since heard about the muffler story - a bit of bad luck there, but my point about driving it and tinkering with it still stands; if it happened on a local drive, and not on a 3000 km epic adventure, it could have been dealt with before the unintended consequences. It does make a good story and obscure diagnosis though - how can a starter solenoid blow up a muffler! :eek:
     
  20. simon klein

    simon klein Two Time F1 World Champ
    Owner Silver Subscribed

    Feb 25, 2009
    28,802
    North Qld
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    simon klein
    Your thread on 16 inch rims/wheels,April...didn't take much digging.

    That is something you've worded/diagnosed incorrectly and I'm not going into it publicly...ring me or I'll ring you re...if you like.
     
  21. Temerian

    Temerian Formula Junior
    Silver Subscribed

    Jun 17, 2014
    432
    Manhattan
    Full Name:
    Rick Temerian
    Hey guys- Let's not slag each other's cars here. There is enough hate in the world for our 365/400/412 models without bringing anything petty into our forum. Simon- I think your car looks great, and your's too, Patrick! I suggest you guys have a drink next time you see one another and send me the bill. Cheers!
     
  22. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
    Full Name:
    Patrick
    Yes, "unloved" was a poor choice of words - Simon loves his cars, and that one in particular (his raving about how good it was factored in me buying the 400). He also drives it like he's only got minutes to live - lots of fun seeing him start to drift it at... the speed limit :p. I still think he needs to have both his Ferraris close by so he can enjoy them more often, and attend to little niggly things at his leisure. Whatever you do, Rick, don't offer to pick up Simon's beer tab - it's mighty hot up in the tropics!
     

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