RacerX Upper Rear Control arm. Is it resilient enough for dirt...?

[grumpysnapper]

Wondering if any body might be able to tell me their experiences with the Racer X upper rear control arms?

Have users been happy with the quality, or have there been any issues over time?

I'm mainly interested in the weight savings of their arms, and my usage is not for finding extra camber, but will primarily be on rougher tarmac and dirt.

Not so concerned with the inner bushes, more the structural design/welding aspects along with the 'ball joint'/stud.

So, basically, can they cope with fairly harsh use over a long period of time?

Many thanks.

Lyndon

[ZDan]

I would bet that the performance advantage from the "weight savings" is very close to zero....

For structurally critical parts, I tend to stick with OEM unless there's a very compelling reason otherwise and the alternative design has been proven out with a LOT of street and track miles... OEM parts generally have orders of magnitude more real-world testing done on them.

Also in the event of a big hit, a mild-steel part that yields and bends may be safer than a welded 4130 chrome-moly part that might fracture/break.

[DarkPira7e]

These should be the same as 08-14 wrx/STI parts, so I would check in at NASIOC as well.

[Code Monkey]

Almost 20,000 miles and 2+ years later.... zero problems with mine.

[SuperTom]

Yeah 8lbs loss in the rear is exceptional. My research into these is that you have to alignment done as you are installing these. I would contact them since you concern is robustness

[grumpysnapper]

Originally Posted by ZDan

I would bet that the performance advantage from the "weight savings" is very close to zero....

For structurally critical parts, I tend to stick with OEM unless there's a very compelling reason otherwise and the alternative design has been proven out with a LOT of street and track miles... OEM parts generally have orders of magnitude more real-world testing done on them.

Also in the event of a big hit, a mild-steel part that yields and bends may be safer than a welded 4130 chrome-moly part that might fracture/break.

Thanks mate, I agree with you about the the robustness of OEM components (generally), and have basically continued to use primarily OE suspension except for dampers and springs.

I guess I've been quite anal about weight, particularly when it comes to unsprung or "partly" sprung.

What has been a little frustrating is that many of the gains I had made in the rear, have to certain extent been negated by a couple of recent upgrades ( HD drive shafts, and custom rear dampers)...which have added ability with the cost of weight.

Hence, 4 kg's less, of moving suspension mass is worth while to me. If it were fully sprung, I would tend to agree with you on cost v benefit.

Lyndon

[grumpysnapper]

Originally Posted by DarkPira7e

These should be the same as 08-14 wrx/STI parts, so I would check in at NASIOC as well.

Great idea, thanks.

Lyndon

[ZDan]

Originally Posted by grumpysnapper

Hence, 4 kg's less, of moving suspension mass is worth while to me. If it were fully sprung, I would tend to agree with you on cost v benefit.

Yeah, I hear you. In the scheme of things, 8 lb. (3.6kg) isn't a lot, but the only way to meaningfully reduce weight requires a lot of little contributions. In that sense -8 lb. is a decent chunk.

I'm curious what the stock arms actually weigh, 8 lb. seems like a lot to remove from parts that aren't that big/massive to begin with... Tube structure is a lot more efficient, but still...

It looks like the heavier end of the control arm is the sprung end, so reduction in unsprung mass will be somewhat less than half the total mass reduction.

Of course it'd be awesomer to remove weight that is high and forward, but these parts are low and aft.

All about benefit vs. risk, cost, $$$, and effort expended!

[Racecomp Engineering]

The new Subaru outback use nice looking aluminum upper arms now. I'd love to see if the geometry is the same as ours...I'm guessing they're not but would be great if those fit.

- Andrew

[SuperTom]

Originally Posted by Racecomp Engineering

The new Subaru outback use nice looking aluminum upper arms now. I'd love to see if the geometry is the same as ours...I'm guessing they're not but would be great if those fit.

- Andrew

please keep us posted if they may work. Like others I don't need the extra alignment abilities/ nor the hassle or $$ paying a shop to install and align at the same time of the Racer X arms. I just want something lighter

[grumpysnapper]

Originally Posted by ZDan

I'm curious what the stock arms actually weigh, 8 lb. seems like a lot to remove from parts that aren't that big/massive to begin with... Tube structure is a lot more efficient, but still...

It looks like the heavier end of the control arm is the sprung end, so reduction in unsprung mass will be somewhat less than half the total mass reduction.

I've just had a new pair put in when I changed dampers (easier to buy the completed arms than to buy and change the bushes) and they are ridiculously heavy, solid cast metal. Obviously very strong though.
They look and feel like they could be from a steam locomotive!
And I forgot to weigh them...of course.

Lyndon

[grumpysnapper]

Originally Posted by Racecomp Engineering

The new Subaru outback use nice looking aluminum upper arms now. I'd love to see if the geometry is the same as ours...I'm guessing they're not but would be great if those fit.

- Andrew

That is a great idea mate...literally the perfect solution for me.
Fingers crossed.

Lyndon

[Racecomp Engineering]

Originally Posted by SuperTom

please keep us posted if they may work. Like others I don't need the extra alignment abilities/ nor the hassle or $$ paying a shop to install and align at the same time of the Racer X arms. I just want something lighter

Haven't even checked the parts department yet to see if they have any in yet, but we'll start making calls soon.

- Andrew

[strat61caster]

I'll take the cast OE lumps for tough racing every day of the week, especially if the car sees Street usage as well, those things are almost designed for the lifetime of the car, you'll be replacing the after market sphericals on an annual or semiannual basis if you're serious.