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Front Lower Control Arm Needs Replacing

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captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
On the prothanes, the front bushing would deform and fail on the trailing side (typically from under breaking). I put large washers on the rearward bushing to take up the gap and provide some sort of thrust surface for braking forces but that only bought me 20-25% more life out of them. The last set melted after some fall events in Arizona.
 

ChrisM

Mostly harmless.
1,180
1,419
Exp. Type
HPDE
Exp. Level
3-5 Years
South Carolina
On the prothanes, the front bushing would deform and fail on the trailing side (typically from under breaking). I put large washers on the rearward bushing to take up the gap and provide some sort of thrust surface for braking forces but that only bought me 20-25% more life out of them. The last set melted after some fall events in Arizona.

Dang. I have Prothanes on mine right now. Granted, I'm not even running at 10% of your ability, so they're probably fine, but all the more reason to replace them eventually.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
I'll dig around and see if I have pictures of how I set them up to prolong life. Keep in mind I am also running 315mm wide R7/A7 and some slicks here and there to generate some punishing loads for the bushings. @ArizonaBOSS however also runs the same prothanes, and has never had an issue. So not sure the common denominator, maybe they had a production change at some point, etc.
 

ArizonaBOSS

Because racecar.
Moderator
8,730
2,734
Arizona, USA
Yeah not sure what is up with that, the Prothanes in my car are still intact after at least 3 seasons of abuse. I seem to be the outlier, however.
Thinking to convert to the 302S delrin bushings over the summer when the shocks are out for rebuild.
 

PatientZero

@restless_performance
825
865
Exp. Type
Autocross
Exp. Level
10-20 Years
Kansas City, Missouri
BACK FROM THE DEAD!
I searched and this thread seemed to be most relevant to my question.

I want to freshen up the front LCA's on the Budget Track Beater before I head to the track. I want to keep the car as close to stock as possible but I'm willing to upgrade whatever is necessary to be track worthy. What would be the best bang for the buck replacement? The car is getting Bilsteins, Ford Springs, and 200TW tires, I don't intend to ever go anymore extreme than that.

-Moog stock replacement arms
-Stock GT500 arms
-Steeda arms(it would seem this is not the answer)
-Replace bushings on the stock arms with Prothane/Whiteline
-Something else?
 

PatientZero

@restless_performance
825
865
Exp. Type
Autocross
Exp. Level
10-20 Years
Kansas City, Missouri
among those options, gt500 arms. moog has gone to trash over the last decade. I've used prothane bushings on a stock arm. melting the bushing off the stock arm is a pain in the ass, but it cant stay stuck if its a liquid
Are they straight bolt on? I'm seeing something about 16mm vs 18mm ball joints.
 
1,163
2,121
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
If you go the route of removing the stock hydro-bushings, here’s a helpful link for a “cleaner” removal procedure.

 
67
48
Exp. Type
HPDE
Exp. Level
3-5 Years
NJ
FWIW I just had a very new prothane front bushing fail on my 4th DE session at the Glen. Wont do it again after the nightmare of removing the stock bushings. Will be upgrading to the 302s/r bushings on new arms with the Howe extended ball joints. Frustrating.
 

Grant 302

basic and well known psychic
Hello everybody

What do you think of the new BMR A-arm?
Looks more stable than the old one.



Greetings from Switzerland
View attachment 59550

I wouldn’t use it. Not on the street or road course.

Goofy transitions aside, I don’t see how it’s welded properly in some places. Like where three tubes meet. Still places I would call ‘stress risers’. Seems like they’re avoiding more proper solutions with more plates or gussets.

Curious what @Fabman and @Norm Peterson will see.

Best thing I can say about it is that it shouldn’t be as bad as the last version. But I’d stay away.
 

Fabman

Dances with Racecars
6,519
8,155
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I wouldn’t use it. Not on the street or road course.

Goofy transitions aside, I don’t see how it’s welded properly in some places. Like where three tubes meet. Still places I would call ‘stress risers’. Seems like they’re avoiding more proper solutions with more plates or gussets.

Curious what @Fabman and @Norm Peterson will see.

Best thing I can say about it is that it shouldn’t be as bad as the last version. But I’d stay away.
Certainly more rigid than the previous generation, but with all that added weight what are the advantages?
I ran the previous iteration BMR arm for quite some time without failure, but I wouldn't call them light or particularly stiff, and these new ones are even heavier so again, what are the advantages? A Boss 302s arm is very good, add some good bushings and it's hard to beat without going to a dedicated race arm. (read Rod ends) I'm going to agree with Grant here, I don't think this is a worthwhile upgrade for track use. Money could be better spent elsewhere IMHO.


You WILL need a bumpsteer kit with these.
 
Last edited:

TymeSlayer

Tramps like us, Baby we were born to run...
3,787
2,740
Exp. Type
HPDE
Exp. Level
3-5 Years
Brighton, Colorado
I run these on my '12 Boss mostly on the track and have had zero issues. They're married with BMR's radiator support, front sway bar and K-member. I don't know about the weight as IIRC, these were close to the same but I saved over 20 pounds on the K-member so it didn't bother me. I also recall our friend down in Chile having an BMR a-arm crack on him but I'm not sure that wasn't a gen1 model. I do regular checks on mine and so far, so good.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
I basically made the Boss 302s arms using my stock arms. Removed them, pressed out the bushings, removed the factory ball joints, had Howe Racing threaded inserts TIG welded in and new powder coating. I reinstalled the arms with the threaded Howe Racing ball joints and Prothane bushings. They have been in the car about a year and a half now without issue.
 
1,163
2,121
Exp. Type
Time Attack
Exp. Level
5-10 Years
SoCal
I basically made the Boss 302s arms using my stock arms. Removed them, pressed out the bushings, removed the factory ball joints, had Howe Racing threaded inserts TIG welded in and new powder coating. I reinstalled the arms with the threaded Howe Racing ball joints and Prothane bushings. They have been in the car about a year and a half now without issue.

Does the hole where the ball joint is pressed out have to be opened up for the Howe’s weld in collar to fit?
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
No, it was designed to fit the stock arms. Press out the old ball joints and the sleeve slides right in. The collar and threaded extended ball joints are what is used in the build of the Ford Racing arms. It is a hybrid style ball joint that was made specifically for the Boss 302 r/s cars built by Watson. Here are a couple of pictures from when I did it.

IMG_0492.jpg

IMG_0489.jpg
 

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