R-springs on GT350

Discussion in 'Suspension and Chassis' started by C7 B8, Dec 29, 2015.

  1. C7 B8

    C7 B8 TMO Advanced

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    Hi, anyone planning to use R-springs from FP or aftermarket for track use? I believe R's are stiffer and ~1/2" shorter in front. BTW on MR.
     
  2. VoodooBoss

    VoodooBoss Rick Moderator

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    Yes we've been discussing this since early August when I spoke with a couple of Ford VDE's at the Monterey historic races. It does lower the front 1/2" and they are stiffer. What needs to be considered is how that will affect the balance of the car. Early reports for the non R's is there's some understeer and stiffer springs could make that worse. Then again with the PSC2 tires maybe it won't be an issue. Ford Performance is also coming out with lowering springs so I hope they are available by early spring. Our experience with Boss lowering springs was they took a LONG time from concept to market. ;) What might work even better is a front spring that splits the difference in stiffness and lowers the car.
     
  3. ArizonaBOSS

    ArizonaBOSS Because racecar. Moderator

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    The stiffer front rate (and resulting understeer) could be compensated with a stiffer rear bar; but you may be giving up overall grip in exchange for balance.
     
  4. VoodooBoss

    VoodooBoss Rick Moderator

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    Well in theory if you added the stiffer and shorter R front springs and added the shorter RSB arms and run the PSC2 R tires you should be pretty close. The calibration in the MRC dampers is different but I'm not sure if or how much they enter into the balance of the car.
     
  5. steveespo

    steveespo Lord knows I'm a Voodoo Child Moderator

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    Drew is correct. To improve grip and balance should look to aero improvements up front to go along with stiffer and lower springs. Killing grip in the rear does just that kills grip in the rear and makes a car snappy loose. I would upgrade to R spec on everything, splitter, wing and springs. Wheels yes but not the CF wheels, a more affordable alternative is being made by a vendor here on the site.

    I am personally in a bad place, the pull of the S550 is strong and the GT 350 even stronger. A sale of the original 21 car is being contemplated.
    Thanks Rick, Nick and Gary ::)
    Steve
     
  6. Black Boss

    Black Boss TMO Addict

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    Wow Steve, the force must be strong ;) never thought you'd consider a sale of the 21 car......

    In addition to Steve and Drew's comments, for those contemplating shorter springs, both the front and rear mag shocks have ride height sensors -- a re-cal may be required if lowering either end....
     
  7. VoodooBoss

    VoodooBoss Rick Moderator

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    You're welcome. ;D Have you seen the new Star Wars movie yet?

    The rear springs are the same on all cars and the sway bars are too. The C&D article I posted yesterday quoted Adam Wirth from FP saying that the R has "firmer suspension bushings and larger anti-roll bars." That's the first I've heard of either of those being different. While I wouldn't be surprised on the bushings I've not seen anything else that states the anti-roll bars are different other than the R's having 8mm shorter end links on the rear which will stiffen it up marginally. It sure would be nice to see in writing from Ford what, if any, differences there really are. The only differences on the R that I've been able to determine from my conversations with the VDE's that setup the suspension are front springs, RSB end links, smaller slot gaps in the MRC dampers and different calibration.

    Lighter wheels and sticky rubber upgrades on non R's go without saying for real track use.
     
  8. TMSBOSS

    TMSBOSS TMO Addict

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    Steve. See any movies this past week or so?? LOL.

    Avoid the dark side. Most S550's on track will still be slower than your 21 car.

    Resale on 21 will likely be better later in the year once the 350 bounce has decreased.

    Just my .02.
     
  9. superhero

    superhero TMO Addict

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    I have one thing to add....Don't do it!
    This is just my opion and we all know about them.
    the 21 is something special that is apart of your blood.
    Hell on a fresh set of sticky tires you will hang with the 350.
     
  10. cloud9

    cloud9 Gary

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    I knew it! Well at least we'll have you pioneering all this stuff for us ;D
     
  11. cloud9

    cloud9 Gary

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    I'll never forget him saying "I love this car" at Road America after repairing the rear end troubles. :D But hey, that's what memories are for!
     
  12. VoodooBoss

    VoodooBoss Rick Moderator

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    Bumping this thread to see if any new GT350 owners are considering or have installed different springs.
     
  13. Tob

    Tob TMO Race

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    If Ford Racing releases a spring set I'll be doing it. I'd like to dial out that small percentage of compromise that had to be included in order to meet certain internal engineering standards at Ford. If the 6GR wheels hit the mark those will be going on to with R sized rubber.

    Never ends, does it?
    :)
     
  14. ChopSui

    ChopSui Mike

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    Ditto on the FPR Springs
     
  15. C7 B8

    C7 B8 TMO Advanced

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    I spoke with FP regarding using R-springs and response was basically what other members have mentioned already on this thread. Then I asked about lowering just a bit (.5"-.75") with same spring rate while bringing roll-center down a bit. Guy at FP was a bit warmer on the idea but still not supportive until he sees prove on the track. I will be running the R-spec N4S wheels and MM camber plates and thats it. Until someone figures out the proper set-up.
     
  16. VoodooBoss

    VoodooBoss Rick Moderator

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    Never! As soon as my car is produced I'll start the mod process. :p
     
  17. VoodooBoss

    VoodooBoss Rick Moderator

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    The R springs are available on ebay. The part numbers are as follows:

    FR3Z-5560-P & FR3Z-5560-T Left and Right Rear Springs
    FR3Z-5310-M (x2) Front Springs

    http://www.ebay.com/itm/322032099023?item=322032099023&viewitem=&vxp=mtr

    http://www.ebay.com/itm/191821691504?item=191821691504&viewitem=&vxp=mtr

    http://www.ebay.com/itm/201537053553?item=201537053553&viewitem=&vxp=mtr
     
  18. cloud9

    cloud9 Gary

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    Cool when are you installing?
     
  19. VoodooBoss

    VoodooBoss Rick Moderator

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    I think @8250RPM is going to be first. ;)
     
  20. cloud9

    cloud9 Gary

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    I'm assuming there's enough range in the damper programming to accommodate the shorter/stiffer travel?
     

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