Ford Performance GT350 M-5300-W spring and GT350R spring comparison

bpracer said:

While that is true. if they were made out of stouter steel, they would have to be more visually shorter.

I'm just saying if you're looking for something stiffer than the R springs (which I have) for a car running slicks or stickier tires than SC2s then these probably aren't going to do you any good other than looks.

I provided the R springs for Vorschlag to rate against my stock Track Pack springs.

Epiphany - check the wire diameter of the rear spring over its entire length. The Track Pack spring does not to use a constant wire diameter. At the area where it goes into coil bind, they are smaller diameter wire. Not the typical thing you see...

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I was thinking the same thing as Voodoo, along the lines of material properties and/or differing heat treatments in a similar looking spring affecting the rate, etc. In this case, the FRP spring should provide more drop. For the record, spring free heights were near identical.

I'll check the spring for any diameter variance about it's length. Thanks for the insight.

I would have loved the R springs but stiffer.

I can't see myself dropping my car anymore. It hits everything on the track and off.

Good info as always! I didn't know the springs were going to be blue

I look forward to seeing some before/after pics from the group buy thread.

I would be surprised if the fronts aren't basically identical to the R springs.

Epiphany said:

I was thinking the same thing as Voodoo, along the lines of material properties and/or differing heat treatments in a similar looking spring affecting the rate, etc. In this case, the FRP spring should provide more drop. For the record, spring free heights were near identical.

I'll check the spring for any diameter variance about it's length. Thanks for the insight.

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FWIW - Modulus of Elasticity or Young's Modulus is the material property that determines the stiffness of the material. The Modulus in Torsion of spring steels (11.5 Ksi) does not really vary with temper, heat treating, etc. so the spring rate would not be effected, unless the material was changed all together to a different family, such as Stainless Steel (10.0 to 11.0 Ksi) or High Temp alloys, like Inconel (11.0 to 12 Ksi).

However, the Temper does affect the strength of the spring and it's allowable displacement, so this does factor in the overall spring design, which will impact the spring rate, but for different reasons.

If you have 2 dimensionally equivalent springs with the same spring parameters (Spring dia. wire dia., #coils, free length, etc.) made from spring steel with differing tempers, they will both have the same spring rate, but one might fail (yield) for a given displacement, while the other performs. Thus, if you want to use the weaker material, you would have to change the spring parameters in order to make it work, which will impact the spring rate. So, temper is somewhat related, but in a very convoluted way. It is not a direct relationship. Hope this helps.

Zombo said:

FWIW - Modulus of Elasticity or Young's Modulus is the material property that determines the stiffness of the material. The Modulus in Torsion of spring steels (11.5 Ksi) does not really vary with temper, heat treating, etc. so the spring rate would not be effected, unless the material was changed all together to a different family, such as Stainless Steel (10.0 to 11.0 Ksi) or High Temp alloys, like Inconel (11.0 to 12 Ksi).

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Since we are discussing a compression spring I think the relevant modulus would be Shear Modulus and not Young's Modulus regarding spring characteristics.

No?

Epiphany said:

Since we are discussing a compression spring I think the relevant modulus would be Shear Modulus and not Young's Modulus regarding spring characteristics.

No?

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Yes, I agree. Shear Modulus AKA Torsion Modulus (which is what I stated). Young's Modulus for steel is in the 30 KSI range.

Speaking of modulus, have you ever seen this material? Wonder if some of the top race teams are employ this. I used the 640 for the Optical Bench on a high speed pointing mirror. These materials would be great for brake calipers, among other things.

https://materion.com/products/composites-compounds-ceramics/metal-matrix-composites/supremex

xXANCHORMONXx said:

I would have loved the R springs but stiffer.

I can't see myself dropping my car anymore. It hits everything on the track and off.

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Agreed, would love a stiffer spring but not interested in lower just to be lower. It already requires an act of contortion just to clear the end of the driveway without scrapping :lol:

What is the price difference between the R and Ford Racing spring? Have seen the differences in specifications but don't recall what the prices are for the R springs. Does anyone know? Thanx.

Very informative thread, R&D is why I enjoy this hobby. Can a non-350, meaning GT pony wear these springs? Are the spring towers, for lack of a better term, the same?

Coyote Red said:

Very informative thread, R&D is why I enjoy this hobby. Can a non-350, meaning GT pony wear these springs? Are the spring towers, for lack of a better term, the same?

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I would also like to know this, better handling with a 1/2 inch drop would be perfect for my PPGT

I'm not looking to lower my car at all. I am looking for a higher spring rate as I am moving up to a more aggressive tire for the track. The aftermarket is not doing much for this car as the ROI is just not very big. I thought the GT350R spring was my only option.

havasu486 said:

I'm not looking to lower my car at all. I am looking for a higher spring rate as I am moving up to a more aggressive tire for the track. The aftermarket is not doing much for this car as the ROI is just not very big. I thought the GT350R spring was my only option.

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I'm currently putting coil overs on my R, should be done this weekend.
I'll post pictures when I'm done

Anyone installed these yet? I would like some feedback as far as ride quality and would love pictures.

Does the car drive tighter or is it more comfortable like progressive type springs?