2003 Mustang GT - Rear Tire Size Question

It's also worth considering your goals for the car. If the decisions you're making are all based on how you want the car to look, that's one path. If you are also concerned about how the car feels & handles, that's another path. Lowering an SN95 Mustang 2" with lowering springs will make it handle much worse in performance driving situations. This video is focused on lowering springs for performance driving, but there's a lot of information in it that will help you.


View: https://www.youtube.com/watch?v=uRUXVAJgTiU&t


You should also be aware of the handling issues associated with a 245/315 staggered tire setup. Your car came from the factory with a tendency to understeer. If you make no other mods to the car, putting wider tires in the rear makes the car more likely to understeer when you push the car. Under normal driving conditions, you might never notice this tendency. But, if you start driving aggressively or need to make a sudden evasive maneuver, you could run into an issue.

If you plan to use the car for performance driving, I would not recommend combining a 2" drop with a 245/315 setup.
 
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Depends on how rough your roads are and how much attention you pay. If careful and not trying to off road 2 inch is perfectly fine and will make it look a ton better.

Depending on miles you may look at ball joints and other wear items as lowering will speed up failure on prior worn parts. But don't skip the caster camber plates.
Depends on how rough your roads are and how much attention you pay. If careful and not trying to off road 2 inch is perfectly fine and will make it look a ton better.

Depending on miles you may look at ball joints and other wear items as lowering will speed up failure on prior worn parts. But don't skip the caster camber plates.
Okk ty sm! Where can i get the caster camber plates? and i have to get tires too! But i dont off roading.
 
Where can i get the caster camber plates?
You have options when it comes to CC plates. If you don't plan to use coil overs now or in the future, you can use 3-bolt CC plates. I've used Steeda 3-bolt CC plates for over a decade, and they've worked very well on my autocross cars.


Steeda's instructions are clear and available online. It's a good idea to look at the instructions for any of the CC plates you plan to buy.

I've purchased, but haven't used, a set of J&M 3-bolt CC plates for a future project. I think they're a good, relatively inexpensive option. J&M's instructions aren't as detailed, but I've had good experiences getting answers from J&M via email.

American Muscle sells the J&M CC plates:

 
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You have options when it comes to CC plates. If you don't plan to use coil overs now or in the future, you can use 3-bolt CC plates. I've used Steeda 3-bolt CC plates for over a decade, and they've worked very well on my autocross cars.


Steeda's instructions are clear and available online. It's a good idea to look at the instructions for any of the CC plates you plan to buy.

I've purchased, but haven't used, a set of J&M 3-bolt CC plates for a future project. I think they're a good, relatively inexpensive option. J&M's instructions aren't as detailed, but I've had good experiences getting answers from J&M via email.

American Muscle sells the J&M CC plates:

Ty so much!
 
You have options when it comes to CC plates. If you don't plan to use coil overs now or in the future, you can use 3-bolt CC plates. I've used Steeda 3-bolt CC plates for over a decade, and they've worked very well on my autocross cars.


Steeda's instructions are clear and available online. It's a good idea to look at the instructions for any of the CC plates you plan to buy.

I've purchased, but haven't used, a set of J&M 3-bolt CC plates for a future project. I think they're a good, relatively inexpensive option. J&M's instructions aren't as detailed, but I've had good experiences getting answers from J&M via email.

American Muscle sells the J&M CC plates:

You have options when it comes to CC plates. If you don't plan to use coil overs now or in the future, you can use 3-bolt CC plates. I've used Steeda 3-bolt CC plates for over a decade, and they've worked very well on my autocross cars.


Steeda's instructions are clear and available online. It's a good idea to look at the instructions for any of the CC plates you plan to buy.

I've purchased, but haven't used, a set of J&M 3-bolt CC plates for a future project. I think they're a good, relatively inexpensive option. J&M's instructions aren't as detailed, but I've had good experiences getting answers from J&M via email.

American Muscle sells the J&M CC plates:

Maybe a stupid ? But im learning dont laugh but with the 2” springs does it lower the whole car or just the body?
 
Maybe a stupid ? But im learning dont laugh but with the 2” springs does it lower the whole car or just the body?
There are no stupid questions when you're planning to spend money modifying a car. Your Mustang is a unibody car (it doesn't have a separate body & frame). You are lowering the unibody closer to the pavement. Lowering the unibody too much makes you more likely to scrape the K-member (the thing your A-arms & front springs mount to), your exhaust, and your bumpers over speed bumps. Looking at the photo of your car, it's worth checking to see if your springs are installed correctly. The correct spring position is in this video (around 4:20):


View: https://www.youtube.com/watch?v=oAaEX6_uDRw&t
 
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I'm just gonna leave this here:

1783221306761.webp


:leaving:
 
There are no stupid questions when you're planning to spend money modifying a car. Your Mustang is a unibody car (it doesn't have a separate body & frame). You are lowering the unibody closer to the pavement. Lowering the unibody too much makes you more likely to scrape the K-member (the thing your A-arms & front springs mount to), your exhaust, and your bumpers over speed bumps. Looking at the photo of your car, it's worth checking to see if your springs are installed correctly. The correct spring position is in this video (around 4:20):


View: https://www.youtube.com/watch?v=oAaEX6_uDRw&t

Okk ty for explaining this to me!
 
There are no stupid questions when you're planning to spend money modifying a car. Your Mustang is a unibody car (it doesn't have a separate body & frame). You are lowering the unibody closer to the pavement. Lowering the unibody too much makes you more likely to scrape the K-member (the thing your A-arms & front springs mount to), your exhaust, and your bumpers over speed bumps. Looking at the photo of your car, it's worth checking to see if your springs are installed correctly. The correct spring position is in this video (around 4:20):


View: https://www.youtube.com/watch?v=oAaEX6_uDRw&t

There are no stupid questions when you're planning to spend money modifying a car. Your Mustang is a unibody car (it doesn't have a separate body & frame). You are lowering the unibody closer to the pavement. Lowering the unibody too much makes you more likely to scrape the K-member (the thing your A-arms & front springs mount to), your exhaust, and your bumpers over speed bumps. Looking at the photo of your car, it's worth checking to see if your springs are installed correctly. The correct spring position is in this video (around 4:20):


View: https://www.youtube.com/watch?v=oAaEX6_uDRw&t

I found these will this be to much?
Drops: 99-04 Front - 2.25" Rear - 2.0"
 
I found these will this be to much?
Drops: 99-04 Front - 2.25" Rear - 2.0"
It really depends on what you want to do with your car. I never judge anyone for choosing parts based on how they want their Mustang to look. I just always like to make sure that people considering lowering springs are aware of the performance issues that can arise from lowering a Mustang too much. A car lowered that much with lowering springs will have a stance that many people would find appealing. But, if that car showed up at an autocross event, I would have a polite conversation about how the limited suspension travel is going to negatively impact the handling of the car. There are a lot of springs on the market that fit between the ones you're considering and the ones I would use on my cars. If your only concern is aesthetics, the springs you're considering might be the right choice for your build. But there are some things to consider:

1. Your car appears to be sitting higher than a stock Mustang (but it's been a while since I've seen one/owned one with stock springs). I would try to confirm which springs are on the car and whether or not they are installed correctly.
2. Lowering the car 2.25" F & 2.0" R will probably require shorter front sway bar end links.
3. You have to check the spring rates to see if they are linear or progressive (that will impact ride quality).
4. If the spring rates are really high, you will need aftermarket performance shocks & struts to go along with the lowering springs. Some manufacturers will specify that their springs will work with OEM shocks & struts.
 
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It really depends on what you want to do with your car. I never judge anyone for choosing parts based on how they want their Mustang to look. I just always like to make sure that people considering lowering springs are aware of the performance issues that can arise from lowering a Mustang too much. A car lowered that much with lowering springs will have a stance that many people would find appealing. But, if that car showed up at an autocross event, I would have a polite conversation about how the limited suspension travel is going to negatively impact the handling of the car. There are a lot of springs on the market that fit between the ones you're considering and the ones I would use on my cars. If your only concern is aesthetics, the springs you're considering might be the right choice for your build. But there are some things to consider:

1. Your car appears to be sitting higher than a stock Mustang (but it's been a while since I've seen one/owned one with stock springs). I would try to confirm which springs are on the car and whether or not they are installed correctly.
2. Lowering the car 2.25" F & 2.0" R will probably require shorter front sway bar end links.
3. You have to check the spring rates to see if they are linear or progressive (that will impact ride quality).
4. If the spring rates are really high, you will need aftermarket performance shocks & struts to go along with the lowering springs. Some manufacturers will specify that their springs will work with OEM shocks & struts.
It really depends on what you want to do with your car. I never judge anyone for choosing parts based on how they want their Mustang to look. I just always like to make sure that people considering lowering springs are aware of the performance issues that can arise from lowering a Mustang too much. A car lowered that much with lowering springs will have a stance that many people would find appealing. But, if that car showed up at an autocross event, I would have a polite conversation about how the limited suspension travel is going to negatively impact the handling of the car. There are a lot of springs on the market that fit between the ones you're considering and the ones I would use on my cars. If your only concern is aesthetics, the springs you're considering might be the right choice for your build. But there are some things to consider:

1. Your car appears to be sitting higher than a stock Mustang (but it's been a while since I've seen one/owned one with stock springs). I would try to confirm which springs are on the car and whether or not they are installed correctly.
2. Lowering the car 2.25" F & 2.0" R will probably require shorter front sway bar end links.
3. You have to check the spring rates to see if they are linear or progressive (that will impact ride quality).
4. If the spring rates are really high, you will need aftermarket performance shocks & struts to go along with the lowering springs. Some manufacturers will specify that their springs will work with OEM shocks & struts.
How would you be able to tell if they are installed correctly?
 
The front sits on eibach sportlines with NO rubber isolators - to get it lower. Tires are factory height (25.7) on front. Roughly a 2.5 drop all around on it.
Rear of my mach is on sportlines in this pic but uses a Lower control arm with adjustable spring perches.
Worth noting I drag my prochamber mid pipe a LOT.

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