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1994 impreza L
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126 Posts
Discussion Starter #1 (Edited)
okay, so this was the first step for me as a welder, and proved to be quite interesting. As I'm sure you're all aware, certain L's (I believe the FWD versions) did not come with a fender brace, and don't have the lower mounts for one hto be installed.

sooooo....

I wanted one, and felt it would be a good product to offer the community once I become any good. The brace consists of 1/4" mild steel brackets, with a pair of chromoly tubes connecting. I doubt anyone uses stronger materials for this, really.

To mount the sucker up, I first had to make some lower mounts. If any of you lack these lower mounts, and want to be cool like the 2.5rs guys and the rest of the OBD2 crowd, here's how to do it.

First, you'll need supplies
4 nuts, 10mm with thread pitch of 1.25mm, they must be flanged
1 welder, preferably arc. I used a MIG welder
1 electric drill, with a bit slightly smaller than the nut flange
1 tap, 10x1.25, significance of this is explained later
1 length of string

okay, firstly, you must drill out the block-off plates for the lower mounts. Why subaru chose to block these off instead of putting the nut there, I don't know. So now you have four holes in your car.

below the lower mounts, you will notice a rubber boot. This boot has wires running through it to the door, speaker, window, etc. unplug the boot so you create a third hole.

Dangle the string through one of the drilled holes, and catch it out of the boot hole. on the boot hole end, put the nut on the string, and then tie a sequence of knots behind the nut. pull the nut so the knots of string fill it, and hold it in place. Now, pull the string through the drilled hole until the nut appears there. Great, now center it. Wouldn't it be nice if that nut stayed there by itself?

Grab your welder, and harden your balls for adventure, because its time to weld your car. With the string pulled tight, and the nut centered, CAREFULLY weld around the perimeter to attach the nut to the car. The idea is that the weld will absorb any rotational forces, but the flange against the body will absorb all the torque. the string will catch on fire and break, so make sure your first spot weld is badass, or that nut will just about be gone for good, I lost two nuts this way. The melting string in the nut threads will protect them from splashing metal. Gooey string is easier to clean off threads than hardened steel.

OK, you will find that you cannot readily thread a bolt into that nut. There is almost certainly a cocktail of string and metal in those threads, and that is where the tap comes into play. Try to clean all that crap out with the tap, and then thread the bolt in to test it. If too many threads get destroyed, you may have to helicoil it, which will be necessary for one of mine.

OK, you have the four mounting points, a welder, and a nearby metal yard. Time to cook up a brace that would make GT-spec crap their pants. Ready? Let's go!

Grab some strip metal of your choice to make brackets, use a ruler to figure out the ideal size for the upper and lower bracket. Use tracing paper to map the mounting holes, then, center punch them onto your brackets after you cut them. You will want to orient the holes so the brackets are "facing" each other, so to speak.

now you have brackets, so you need to connect them! You really have three different choices here:
1. strip of metal
2. some number of metal tubes (I used two per side)
3. square metal tubes

With a round tube, you will need to weld end caps from a square sheet, so it can be cleanly welded to the brackets. Using whatever length tube/strip you choose, weld it to the brackets to connect them. Apply a coat of your favorite rust-inhibiting paint, and you're done.

So the question arises, what does a fender brace even do? This is a hard question to answer with your fenders on, but basically there is the door jam, then a piece of metal that goes to your strut tower. A moments inspection reveals that while both are pretty sturdy pieces of material, they are connected with really, really crappy welds. Mine literally look like painted metal poops. So, there is flex here. This flex probably has some play in the possibility of hood cracks, and at the very least will cause you to have imprecision in the steering and front suspension, especially under braking or heavy load. Now that I see how this all is, I would say a heavier duty fender brace should be a requirement along with any upgrade to spring rate in the front of the car. Further triangulation of the brace from the lower door mounting point could only help this positive effect.

Driving impression? I found the braces to make the car turn much more positively, reducing understeer slightly and improving driver confidence. If I had to recommend a brace, I'd say the GT-spec version which mounts to the door mounts in addition to the fender brace mounts would be best, because it has the greatest triangulations to the fender welds. It is massively expensive though. Any other brace should work wonders over the stock one, or lack thereof entirely.

For materials to make a brace with, I'd recommend chromoly, or a high carbon steel. 7075 aluminum would produce a nice brace for you lightweight buffs. Titanium is ideal, but tricky and expensive. You want the stiffest material possible.

pics up in the afternoon
 

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Registered
1994 impreza L
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126 Posts
Discussion Starter #3
here are the pics of the brace installed



sorry for the somewhat crappy pics, they hardly do the brace justice
 
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