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Rear Lower Control Arms - Ford Performance vs Ford OEM Difference?

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I'm sure functionally they are the same (assume they'll have the same bushings), but does anyone have any idea why the design difference between the original Ford GT500/BOSS rear lower control arms (BR3Z5A649B) vs the Ford Performance (M-5538-A)?

The FP ones look like they might be thinner...
FR.jpg
M1.jpegm2.jpeg
 
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It says right in the link
  • Increased bushing durometer and stiffness for high performance applications
 
It says right in the link
  • Increased bushing durometer and stiffness for high performance applications
Yeah but it also says, "Standard equipment on 2007-2014 Shelby GT500, 2013-2014 Mustang GT with Track Pack, and 2011-2014 Mustang GT with manual transmission."

If you search FordParts for OEM GT500 (or BOSS) control arms you get BR3Z5A649B...
 
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OK I found a clue to help with this mystery. Apparently BR3Z-5A649-B is not the original part number. The original part number used on 2012 GT500/BOSS LCAs is BR3V-5538-AB. Found this from looking at forums and eBay listings.

Notice the number 5538 is common to the FP LCAs (M-5538-A). So I'm pretty sure they're the same... but different... :p

I'm thinking it may be a similar situation as the BOSS diff cover which is sold by Ford as DR3Z-4033-B but is also sold by Ford Racing as M-4033-KA ... The Ford Racing one comes as a kit with the bolts but is otherwise the same...
 
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I would buy one of these instead

Maybe in the future! I'm still on the last leg of building this car and my plan is to stay stock-ish until I've got all of the kinks worked out. Then I'll start working on evaluating deficiencies! Right now I've got to refresh a lot of these junk yard parts :) I can tell the LCAs I've got right now are 2012 originals. Rusty and still functional but they make noises and I'm sure they aren't operating at their original level.
 
Couple learning topics here:
-When Ford Performance sells a part in the aftermarket, it's under the 'M' part number designator. The vast majority of them are ""rebranded"" OEM parts or a collection of OEM parts being referred to under a single new part number, though there exists parts tweaked by the in-house race team that wouldn't have existed on any road-going production vehicle (for our year, mostly Boss 302R/S equipment). For parts that are the same as OEM, the 'M' parts are sometimes cheaper than the R3Z parts and sometimes they're not. You gotta do your research and be aware of what's available.

-The part number code for 2011 breaks down as follows, [YEAR][CHASSIS]DEPARTMENT]-[PART NUMBER]-[LETTER VARIANT]
B is 2011 model year (part is new or a revision for MY2011, but can be used on subsequent years). They started with A in 2010 and have been using letters since - until they run out.
R3 is Mustang
Z, most importantly, is Parts Department. Nothing on your car will be stamped or printed with a 'Z' on it from the factory. That's exclusively to refer to parts in a box on a shelf. The Department code will differ depending on who was responsible for the design of the part at Ford. So you'll see V (Domestic Special Order), E (Engine Engineering), 3 (Vehicle Center 3), etc on the physical items but when you search them if you want replacement parts you want to change it to BR3Z since that's how they're catalogued. Just keep in mind sometimes variant codes change, so parts.ford.com is usually one of the better resources to do part research on with the part numbers, regardless on where you end up buying it from eventually. Sometimes the part numbers printed on the parts will be completely different than the part numbers associated with them from the parts department, which adds to the struggle, but parts.ford.com has gotten better about re-directing to the correct part if you enter in the original number. I find it works best via VIN search and there's easy ways to get alternate VINs to search with online if you're looking for something not originally equipped on your vehicle.
 
Couple learning topics here:
-When Ford Performance sells a part in the aftermarket, it's under the 'M' part number designator. The vast majority of them are ""rebranded"" OEM parts or a collection of OEM parts being referred to under a single new part number, though there exists parts tweaked by the in-house race team that wouldn't have existed on any road-going production vehicle (for our year, mostly Boss 302R/S equipment). For parts that are the same as OEM, the 'M' parts are sometimes cheaper than the R3Z parts and sometimes they're not. You gotta do your research and be aware of what's available.

-The part number code for 2011 breaks down as follows, [YEAR][CHASSIS]DEPARTMENT]-[PART NUMBER]-[LETTER VARIANT]
B is 2011 model year (part is new or a revision for MY2011, but can be used on subsequent years). They started with A in 2010 and have been using letters since - until they run out.
R3 is Mustang
Z, most importantly, is Parts Department. Nothing on your car will be stamped or printed with a 'Z' on it from the factory. That's exclusively to refer to parts in a box on a shelf. The Department code will differ depending on who was responsible for the design of the part at Ford. So you'll see V (Domestic Special Order), E (Engine Engineering), 3 (Vehicle Center 3), etc on the physical items but when you search them if you want replacement parts you want to change it to BR3Z since that's how they're catalogued. Just keep in mind sometimes variant codes change, so parts.ford.com is usually one of the better resources to do part research on with the part numbers, regardless on where you end up buying it from eventually. Sometimes the part numbers printed on the parts will be completely different than the part numbers associated with them from the parts department, which adds to the struggle, but parts.ford.com has gotten better about re-directing to the correct part if you enter in the original number. I find it works best via VIN search and there's easy ways to get alternate VINs to search with online if you're looking for something not originally equipped on your vehicle.
Good info! Thanks. Bookmarked!

I did notice that the FP part has a sticker on it that reads: 9R3V-5538-AA

When it came to the diff cover, I bought the FP part b/c I couldn't see any differences between the two and it came with the bolts. This one comes with the bolts but ... trying to decide if the design is an improvement or a result of manufacturing differences. I'd lean toward a design change since it seems they are able to just repackage Ford OEM parts. They could have just made a package with the bolts just like the diff cover. Guess I'll just have to take my best guess!

I'm surprised that this discussion hasn't been had multiple times before. I was able to find one other conversation on it here:

But ultimately they could only come up with the fact that the FP part wasn't factory installed on anything.
 
Often the Ford Performance packages are quite nice since they do include all the parts needed for any particular upgrade, like coming with the fasteners.
The discussion likely hasn't been had many times since most people go with aftermarket solutions because 1. they can't get replacement bushings for what they have 2. the new OEM arms cost as much or more than aftermarket arms and 3. the OEM stamped steel pieces are very heavy. So your common dude probably sees more prospective value in the aftermarket part, since they can be had starting at $100/pair with polyurethane bushings that can be greased via zerk and replaced when worn out in a package that's often much lighter. Not to say that's necessarily matches everyone's values, I'd love more use of rubber bushings that are voidless/solid or have different durometers for sporty street applications, but with some of these 'easy' parts I find the general populace seems to trend towards value propositions.
 
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Often the Ford Performance packages are quite nice since they do include all the parts needed for any particular upgrade, like coming with the fasteners.
The discussion likely hasn't been had many times since most people go with aftermarket solutions because 1. they can't get replacement bushings for what they have 2. the new OEM arms cost as much or more than aftermarket arms and 3. the OEM stamped steel pieces are very heavy. So your common dude probably sees more prospective value in the aftermarket part, since they can be had starting at $100/pair with polyurethane bushings that can be greased via zerk and replaced when worn out in a package that's often much lighter. Not to say that's necessarily matches everyone's values, I'd love more use of rubber bushings that are voidless/solid or have different durometers for sporty street applications, but with some of these 'easy' parts I find the general populace seems to trend towards value propositions.
A lot of the Ford kits are/ were mandated in the SCCA as well
 
Figured it out! While researching these parts I came across an LCA installation video on a 3V. The part that was removed looked just like the FP part except it was old and beat up which is weird b/c I thought I'd established that these things didn't come factory installed on anything. But the part was painted black and not gray. So I figured I should check the parts catalogue for the rear lower control arm for a 3V and guess what?
3v.jpg
Then it hit me, Ford Performance says, "Fits 2005-2011 Mustang GT, 2005-2014 Mustang GT with auto transmission, and 2005-2014 Mustang V6. Standard equipment on 2007-2014 Shelby GT500, 2013-2014 Mustang GT with Track Pack, and 2011-2014 Mustang GT with manual transmission."
The listing for BR3Z-5A649-B says, "Ford Mustang 2011 - 2014", and it is also listed as the 2011-2014 GT500 LCA.

Part number comparison:
Factory 2008 GT500:​
7R3V-5538-AB
FRPP GT500:​
9R3V-5538-AA
Ford Parts 2010 GT500:​
9R3Z-5A649-A
Ford Parts 2011 V6/GT:​
AR3Z-5A649-B
Factory BOSS:​
BR3V-5538-AB
Ford Parts 2012 BOSS/GT500:​
BR3Z-5A649-B

If B is 2011, then A is 2010. I'd guess that 9 is 2009. And the, "V" appears to match factory installed part numbers. A little more research turned up these actual 2008 GT500 LCAs on eBay (P/N: 7R3V-5538-AB). Apparently, the FP LCAs are in fact the factory 2010 GT500 LCAs. It appears that the bushings are the same but the FP arm itself is of an older but compatible design. Why did they change the design? Who knows! But all this time I was thinking that the folded steel of the OEM part looked like it would be stronger than the riveted FP part. Also, I noticed that the package weight on the FP parts (2 LCAs including hardware) is 16.9 lbs. Ford lists the weight of one BOSS LCA as 5.9 lbs. I found it hard to believe that those 4 bolts weigh 5 lbs. so I took another look at the 2010 GT LCA. Ford lists it as weighing as weighing 6.95 lbs. So it appears that the newer LCA is also a pound lighter.

Let me know what you guys think, but for future reference, if anyone else is trying to decide between these two, it looks to me like the Ford part gets the edge!
 
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I think these are the ones you are looking for.
I wish Ford and everyone else would quit calling them" lower control arms" when they are really trailing arms.
LCAs run east and west
Trailing Arms run north and south.


View attachment 99198
So, Rob. Trailing arms run the same direction as the rims and control arms run away from the Rims? Asking for a friend!
 
Not to say that's necessarily matches everyone's values, I'd love more use of rubber bushings that are voidless/solid or have different durometers for sporty street applications, but with some of these 'easy' parts I find the general populace seems to trend towards value propositions.
Here you go: non voided rubber with a sleeved bushing. Seems to work pretty well for a stock+ standpoint.

1729216788428.jpeg
 

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