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R-springs on GT350

C7 B8

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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.
 

VoodooBoss

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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.
 

ArizonaBOSS

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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.
 

steveespo

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ArizonaBOSS said:
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.
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
 

Black Boss

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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....
 

VoodooBoss

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steveespo said:
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
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.
 

TMSBOSS

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steveespo said:
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
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.
 

superhero

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steveespo said:
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
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.
 

cloud9

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steveespo said:
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
I knew it! Well at least we'll have you pioneering all this stuff for us ;D
 

cloud9

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superhero said:
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.
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!
 

Tob

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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?
:)
 

C7 B8

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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.
 

VoodooBoss

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Tob said:
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?
:)
Never! As soon as my car is produced I'll start the mod process. :p
 

VoodooBoss

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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
 

cloud9

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VoodooBOSS said:
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
Cool when are you installing?
 

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