Foundry on PP Car - Disadvantages?

[Norm Peterson]

why does the pp have 255s in the front when just the foundry option has 265s?

When you go to a bigger wheel diameter but keep the tire OD essentially the same, the tire sidewall gets shorter. This reduces the air volume, which is the main determining factor in load capacity @ inflation. To recover the air volume (and the rated load capacity) that would be lost going from, say, 255/40-19 to 255/35-20, you have to make the tire section width wider. Hence 265's.

Though 20" wheels will ride a bit stiffer, isn't that the purpose of a handling pack, to reduce body lean?

Making the tire stiffer does not make the suspension any stiffer. While it's true that roll would get reduced with stiffer tires, it's a much smaller effect than the gains potentially available from stiffening the suspension.

If you like numbers, tires might be responsible for half to maybe 3/4 of a degree per lateral g of cornering. The suspension is more like 2.5°/g - 3°/g, or three to six times more flexible and where the significant reductions in roll are obviously far easier to come by. Or, think of it this way - it's fairly easy to reduce roll by more than half a degree/g by stiffening the suspension. The only way to gain that much roll stiffness in the tires would be to fill them with something like cement instead of air. If you're really hardcore, you could reduce roll by a full degree/g in the suspension alone. But that would be flat-out impossible to achieve in the tires when there isn't even that much there to begin with.


Norm

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[Ericc B]

I love the design of these wheels as well, they are bar none the most attractive OEM wheels ever fit on a Mustang.

That being said I wouldn't want them on my car because they are heavy as fcuk. Due to their high ET value they also sit too deep into the wheel wells, which can only be corrected with spacers. And that adds even more overweight.

 

[BmacIL]

I assume it was understood that what I suggested was tuning within the same platform (in this case the S550 with different variants only in that platform). My response was because "EFI" suggested the car was not tuned to the 19" wheel/tire package, which I do not necessarily agree with.

As for the Foundry wheels/tires, I love the look but I'm concerned just how much ride and handling degradation will happen. Sounds like maybe not too much.

Thanks for the info.

I should've clarified more. The 20" wheel cars have unique damper tuning and the addition of the upper K-brace that other non-Performance Pack cars do not get, precisely because of the added weight and smaller sidewall.

 

[Binfordtools]

I should've clarified more. The 20" wheel cars have unique damper tuning and the addition of the upper K-brace that other non-Performance Pack cars do not get, precisely because of the added weight and smaller sidewall.

So the PP and also the cars with 20" from the factory have unique tuning compared to a "regular" Mustang GT?

 

[BmacIL]

So the PP and also the cars with 20" from the factory have unique tuning compared to a "regular" Mustang GT?

Yes. The 20" wheel tuning is closer to the 'regular' than the PP, but still different.

 

[treborwd22]

While there may be some truth to what's been said, for the average mustang owner what difference does it make? Unless you race your car for money and need the extra 10th of a second to make the difference between winning or losing, get what makes you happy. Everyone claiming this and that about feeling the difference I'm sure have not swapped out the PP wheels for the Foundry. I had the foundry wheels and swapped them for the PP wheels. Absolutely no difference in how the car handles. But... I don't track my car for money and I'm sure if I did I wouldn't be trading for stock wheels

 

[Binfordtools]

While there may be some truth to what's been said, for the average mustang owner what difference does it make? Unless you race your car for money and need the extra 10th of a second to make the difference between winning or losing

On the other hand, Mustang owners will spend $60 for a drop-in K&N air filter that will net them minimal - if any, HP gains and zero time differences in a race situation. I think we're all looking for any advantage.

 

[Grintch]

On the other hand, Mustang owners will spend $60 for a drop-in K&N air filter that will net them minimal - if any, HP gains and zero time differences in a race situation. I think we're all looking for any advantage.

And on the other, other hand.
If you want to buy heavy wheels because you like the way they look, just buy them. Quit asking for us to validate your choices. You only have to please yourself.

P. S. Heavy wheels are dumb. Narrow heavy wheels are super dumb. :-)

 

[BmacIL]

And on the other, other hand.
If you want to buy heavy wheels because you like the way they look, just buy them. Quit asking for us to validate your choices. You only have to please yourself.

P. S. Heavy wheels are dumb. Narrow heavy wheels are super dumb. :-)

About spit out my drink! :lol:

 

[GT-SV]

After all the “dumb” talk, I’m surprised replacing the factory wheels with lighter forged wheels wasn’t mentioned. But buried in this thread is a little bit of useful information.

 

[robw_39]

All the Mustang factory wheels are heavy I believe they are made of lead...


I will be selling some lead wheels soon after I pick up my 18 GT...

 

[GreenS550]

I put a set of the forged gt500 wheels on my '11. I know they were heavy because I weighed them when I shipped 'em on Ebay. But, back to the 20" wheels. Tires make a ton of difference on handling. And gripping. Like I've said before, these Michelin a/s tires really grip from a stop or moving. Super impressed.

I didn't know there was a difference in the suspension on a non PP car with the 20" foundry wheels. The car does have a decent amount of body lean. Got spoiled with the Tokicos on the '11.

 

[BmacIL]

I put a set of the forged gt500 wheels on my '11. I know they were heavy because I weighed them when I shipped 'em on Ebay. But, back to the 20" wheels. Tires make a ton of difference on handling. And gripping. Like I've said before, these Michelin a/s tires really grip from a stop or moving. Super impressed.

I didn't know there was a difference in the suspension on a non PP car with the 20" foundry wheels. The car does have a decent amount of body lean. Got spoiled with the Tokicos on the '11.

Outside of the addition of the front K brace, it's just damper tuning. That doesn't reduce roll any. There are quite a few ways to fix that problem without killing the ride or breaking the bank .

 

[SVT-DADDY]

Outside of the addition of the front K brace, it's just damper tuning. That doesn't reduce roll any. There are quite a few ways to fix that problem without killing the ride or breaking the bank .

I am about 90% certain that there arent different part numbers for the shocks and struts. I just spent a day of my life pouring over Ford part numbers and its STD,PP,Vert,PP vert.

 

[GreenS550]

what about putting the Ford Perfromance Track Pack on?

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