Aluminum LCA, worth it?

[thall818]

I am thinking about buying some of the aluminum LCAs. My concern is, is it money well spent? Looking at $250/pr. Do they save that much weight, or do they just look cool on the car? Any other benefits?

[RM1SepEx]

save 2lbs each and they look much better IMO

[Frank818]

Also easier on the drilling, no measurement and no internal bracket needed for the bolts/nuts.

[Goldwing]

I just had a better feeling about the load bearing ability of the shock mounting point with the aluminum LCAs. This isn't a judgement from an educated engineering viewpoint, just a peace of mind move on my part.

[Slatt]

save 2lbs each and they look much better IMO

This is the first time I've seen an actual number assigned to this debate. Did YOU measure them? That would be great if we had info other than the usual 'they are similar weight'.

I agree the attachment for the steel version on an 818 looks a little bit ???

But to answer your question, there is a possible reason to NOT use the aluminum LCA.

History first, the only reason Subaru marketed that aluminum LCA (as far as I know) was to get enough production versions of it sold so they could put it on their rally cars (the key word here is 'homologation').

Second, they wanted that aluminum LCA because it was STRONG.

Now for the third point: that fancy aluminum LCA might be tougher than the frame of your 818. Possibly, if you slide into a curb the LCA will survive and your frame will bend. Which would you rather fix? The LCA or your frame?

As far as I know there is no hard data on this issue, just conjecture (including mine). Myself, I've pretty much decided to get the aluminum.

[Rasmus]

From a post of mine on Nabisco:


Swapping the Front Lower Control Arms on the wagon for the aluminum ones off an STi. Seller said they were "JDM", and that he "Imported them from Japan". :rolleyes: Whatever. Paid him the USDM price.

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4870.jpg
They look like 2004-2006 STi/2006 WRX control arms to me. EDIT: Apparently they're 2007 USDM STi

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4873.jpg
Track is wider. 10mm wider per side? 20mm overall?

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4874.jpg
OEM, 2004 Wagon, Steel, Front Lower Control Arms weight: 4.173kg

http://i162.photobucket.com/albums/t278/RasmusHansen/SubaruParts/IMG_4875.jpg
OEM, 2007 STi, Aluminum , Front Lower Control Arms weight: 3.493kg

A savings of 680 grams per side or 1.360kg (3.00lb) total.

[RM1SepEx]

I weighed them... but only with a low tech scale :) LOL

[custome]

2970129703
Also easier on the drilling, no measurement and no internal bracket needed for the bolts/nuts.

I drilled and tapped mine to avoid machining the bottom side to provide a good seat for the nuts. Due to the fitting of the lower shock bracket, I milled an area for the bracket to sit in. It turned out pretty nice.

[Frank818]

Hey that's a good idea, I wonder if I have access to a machine to do that, I'll check it out.

[metalmaker12]

I am thinking about buying some of the aluminum LCAs. My concern is, is it money well spent? Looking at $250/pr. Do they save that much weight, or do they just look cool on the car? Any other benefits?

Lighter,much stronger, and much better looking. Money well spent IMO

[Bill Waters]

2970129703

I drilled and tapped mine to avoid machining the bottom side to provide a good seat for the nuts. Due to the fitting of the lower shock bracket, I milled an area for the bracket to sit in. It turned out pretty nice.

Nice job.

[DodgyTim]

Attachment 29703
Originally Posted by Frank818
Also easier on the drilling, no measurement and no internal bracket needed for the bolts/nuts.
I drilled and tapped mine to avoid machining the bottom side to provide a good seat for the nuts. Due to the fitting of the lower shock bracket, I milled an area for the bracket to sit in. It turned out pretty nice.

Great idea, I'll be copying that too....

[Boog]

I drilled and tapped mine to avoid machining the bottom side to provide a good seat for the nuts. Due to the fitting of the lower shock bracket, I milled an area for the bracket to sit in. It turned out pretty nice.

Will tapping the aluminum be strong enough? Or do you plan on helicoiling it?
I'd imagine most of the load is in shear so many there is no concern.

[Racebrewer]

If you buy the LCA's new, all the rubber bushings will be fresh (you won't have to replace them) and a nice bag of assorted fasteners is included

[Frank818]

True, along with the ball joints, jam nuts and everything.
Only thing is, the fasteners don't include any bolts, only nuts.

[michael everson]

Boog Heli-coils do not make the threaded hole stronger. It adds longevity if the part is removed often.
Mike

[thall818]

Any idea on the cost of these new?

[Frank818]

Around USD320-355. Under 320, you are lucky. Sometimes shipping is higher where the LCAs are less expensive, so beware, happened to me. I ended bought buying them at 355 with less in shipping so overall price was less than the other place at 320.

[Jaime]

I paid a little over $350 for the SPT version at the dealership.

[nuisance]

Boog Heli-coils do not make the threaded hole stronger. It adds longevity if the part is removed often.
Mike

I think they do make it stronger, because now the threads in the aluminum are one size larger, more bearing area. They do add longevity too.

[Boog]

In effect you would just be changing the weakest point from the threads that interface the bolt to the threads that interface the outer heli-coil edge? That makes sense.