Performance Package Specs

[Zooks527]

First and foremost - no spare unless you plan on packing two different size 19"s.

Nope. There's a single-wheel-fits-under-the-trunk-floor option, but it's not inexpensive.
https://www.automotiveauthorityllc....ang-gt-with-brembo-brakes?variant=35747297481

Tire diameter is correct to protect the LSD in the back. Wheel size and offset are correct to clear the front Brembos.

Sponsored

 

[IPOGT]

I went the FP PP1 route with a 16 Auto. Very happy with the results I received.

 

[dbegley]

dbegley said: ↑
.......the Ford springs are progressive coil springs. That includes the stock springs......Read an interesting article.....Comparing progressive VS linear springs, the progressive not only give a better ride, but actually provide better handling than linear springs.


Count me in for wanting a link.

All the logic I've seen claiming that progressively-wound springs are better for handling than linears doesn't exactly pass the sniff test. Better than base OE, quite possibly. But better than linears when the unloaded side of the progressively-sprung car goes into the "soft" range in a corner . . . uh-uh. Never mind when the two ends of the car don't get the inside springs up into the soft rate regions together (and your LLTD wanders back and forth while the car struggles to take a set).


Norm

I assumed linear was a better way to go on a street sports car. That is what I have on my 68 Shelby Mustang. This article changed how I looked at progressive springs. And this makes sense as to why Ford engineers chose progressive springs for the Mustangs. https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/

 

[GTP]

PP option was $2500 for MY15-17, and then it was increased to $4k for 18/19.

 

[Norm Peterson]

I assumed linear was a better way to go on a street sports car. That is what I have on my 68 Shelby Mustang. This article changed how I looked at progressive springs. And this makes sense as to why Ford engineers chose progressive springs for the Mustangs. https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/

Thanks for the link.

I don't care who wrote that linked article or who they work for - I'm left all but speechless at the misinformation he's spreading. He either doesn't understand spring behavior, or he's OK with the idea that providing incomplete information is OK as long as nobody notices that the part he left out is kind of important. That he chooses to make up his own term, "roll control", which in and of itself I don't have a huge problem with, does lead me to further question his credentials.

Let’s discuss roll control provided by springs. For “linear rate springs” the discussion is easy. They provide no roll control! Think about taking curve at a very high speed. The side of the car on the outside of the turn rolls over and the side of the car on the inside tends to roll up. For discussion sake, let’s assume we have 300lb/in linear rate springs on the front of our car and the car is rolling too much and cornering speed suffers. If we move up to a set of 400lb/in springs in an attempt to “stiffen” the suspension, we fail because the linear rate springs provide no roll control. Think about it. As you enter the same curve at the same speed your vehicle is rolling onto a higher rate spring; BUT the inside of the vehicle is being pushed up by a higher rate spring, also. So there is not improvement with roll control. With linear rate springs, all roll control must come from the sway bar (anti-roll bar).

First off, ALL suspension springs develop roll resistance by virtue of their stiffness, whether they're linear rate, true progressives, or dual-rate. And it can be calculated (the equations are available in any number of books on suspensions, but they're not so involved that an undergraduate mechanical engineer would be unable to derive them from first principles).

But to cut this a bit short, where he's talking about changing a 300 lb/in linear spring up to 400 lb/in and saying the inside of the vehicle is being pushed up by a stiffer spring is misleading. It won't push the inside of the car up more because it is stiffer - in actual fact it'll push the inside of the car up LESS because it takes less motion of the stiffer spring to accommodate the lateral load transfer (load being taken off the inboard spring). IOW, spring rate does not determine the load transfer (that comes from cornering g's, CG height, and track width), it's the load transfer due to the cornering that causes the amounts of compression on the outboard spring and extension on the inboard spring.

I suspect he wants you to think in terms of the soft rate region of progressives or dual-rates matching the linear rate behavior, with the firmer rate providing additional roll resistance ("roll control"). That falls apart when the rate of the linear spring matches the firm rate region of the progressive/dual-rate (logically in that case, the reduced rate of the inboard spring in extension amounts to losing "roll control").


All that said, there could be a justification for slightly progressive springs in some rather fussy cases . . . where the increase in spring rate offsets a drop in "motion ratio" as the suspension moves into bump (spring is compressed).


Norm

 

[frank s]

Thanks for the link.

I don't care who wrote that linked article or who they work for - I'm left all but speechless at the misinformation he's spreading. He either doesn't understand spring behavior, or he's OK with the idea that providing incomplete information is OK as long as nobody notices that the part he left out is kind of important. That he chooses to make up his own term, "roll control", which in and of itself I don't have a huge problem with, does lead me to further question his credentials.
[...]
Norm

"In this universe there are things
that just don't yield to thinking
—plain or fancy— Dude".
—J. Spicoli, PolyPartyPerson

 

[JohnD]

There's a thread that has all kinds of data on springs including a spreadsheet with all the known values out there. Didn't read this entire thread to see if someone already posted this so hopefully this is not redundant data.

https://www.mustang6g.com/forums/threads/spring-rates-drops-all-in-one-thread.44925/

Sponsored