Re-enforcing Front A-arm Suspension Sheetmetal

[Doug Brown]

Here is a simple way to re-enforce the front a-arm suspension point on Festiva's.

I used 14-ga mild steel as this is about the maximum thickness metal I can easily fabricate with hand tools.

You'll need some poster board for cutting out templates/patterns, jig saw with metal cutting blades, mini-grinder, drill motor, bunch of 3/16" drill bits, pneumatic rivet gun, 3/16" stainless pop rivets, a 6" bench vise, couple of ball peen hammers, a dead blow hammer and vice grip pliers.

Make your patterns from the poster board. Transfer shape to 14-ga steel. You can usually find 12" x 12" on E-Bay. Cut out with jig saw using a fine tooth metal cutting blade. Bend the metal approximately 90-degrees (see picture). Use the 6" vice and dead blow hammer to get the initial bend, go back over it with a regular hammer (or ball peen) to get the finished bend. It takes a series of fairly hard hits to get the metal to bend - don't plan on it bending it with only one hit!!

You can also use the vice in making making smaller bends to get a nice tight fit. Use the mini grinder to final shape the piece. Once it all fits pretty closely, mark where you want to put the rivets with a marking pen. Drill the marks out using the 3/16" drill. This is most easily done by putting the metal on some wooden 2 x 4, standing on it, and drilling away. Or use a drill press...

Take the piece back to the car and clamp it in place with the vice grips. Drill thru the car sheet metal and start installing the rivets. You'll need rivets that can be used for .060" to .188" thick metal and .188" to .250" -- depends on how many layers of sheet metal you have to go thru. The 060 to 188 will be the most common.

For further re-enforcing the frame you need a couple of pieces of 20-ga T or U shaped steel to fit and rivet on the outside of the frame. I used pieces from a bed frame that I found at the dump! These are pretty easy to make and the only close fitting is where it comes up against the sheet metal opening where the a-arm bushing fits into. I haven't done it yet, but this joint can be tack welded to further tie everything together.

Last piece is another 20-ga U shaped doubler that vertically re-enforces the sheet metal opening for the a-arm bushing. If you put this piece on, it will need to be both riveted and tack welded for best strength.

It takes about 4-hours to make and install the 90-degree doubler, about 2-hours to make and install the outside frame doubler and about an hour to make the vertical doubler. These times are PER side, so you are looking at a couple of days of work.

[Advancedynamix]

I don't understand why this is beneficial.

[reddragon]

I don't understand why this is beneficial.

When was the last time you entered a festiva into a demolition derby?

[TominMO]

When was the last time you entered a festiva into a demolition derby?

That sounds like a very Darwin Awards thing to do.....

[sasquatch]

I think he's distributing the flex over a larger area and adding stiffness to the area at the same time. sort of like a roll cage mounting plate....? how much benefit he's going to gain from this I don't know.... and how long the rivets will last? who knows.... if there is a lot of flex in that area, I would bet the rivets will loosen and shear off... and he also gave a nice spot for water to hide behind, sit and rust... I would add some seam sealer over it if I where him.

[F3BZ]

you said A arm but looking at the pics i get the impression you are beefing the LCA mounting point. what is your end goal, to strengthen or stiffen? is this a problem area on higher HP conversions? any plans to tie the two LCA mounting points together? what is better, to add a layer of metal or to replace the section with a heavier gage piece formed the same as the OEM piece?

[bhazard]

I don't get it either. Drilling all those holes only weakened the area, which doesn't even see a lot of stress anyway.

And besides, it's prolly still running stock rubber LCA bushings anyway.

[Doug Brown]

OK, some quick replies from my end.

The car, RED, is a non-streetable drag racer. The car is only going in a straight line with a couple of turns to get off the course and return to the pits at relatively slow speeds.

Yes, I'm talking about the LCA area. Sorry for the wrong identification.

It will never be in the rain or forging rivers.....All the metal has been rust converted and primed before assembly and will be primed again and painted before be raced.

It will probably only see a max of 50-miles of use per year. It is NOT a daily driver!

Rivets were the quickest way for me to install the reinforcing pieces. Yes, there is a chance that they can work loose, but if they do it only proves the point that those areas move around and needs re-enforcing. If the rivets loosen, I can remove them and weld the metal together thru the rivet hole.

Even though there are several holes, riveting the pieces of metal together makes them FAR stronger than the original and distributes the load over a larger area. It was far easier for me to add additional pieces of formed sheet metal than to cut everything apart and replace it with very heavy, single layer sheet metal. Plus the metal I added only weighs about a total of 4-lbs, and the weight is up front by the drive wheels.

I am going to be using solid bushings - not rubber - which will impart greater loads to this area. I am also going to get rid of the front sway bar and install basically "traction arms" to locate the lower arm so they don't "walk".

I may install bars that tie together the shock towers and LCA points. Probably will....

And at the end of the day what I'm doing makes sense to me and is something I wanted to do. It is no dumber than bashing in the front frame rails with a hammer or cutting huge holes in the fire wall for clearance.....

I do like feedback from Forum Members and I like and have done a lot of ideas that I have read about on the Forum. Keep it coming!

[ryanprins13]

I am fairly certain this would not be benificial to most people on this forum.
For you however, if you want to do it again or change something instead of rivets i would use paint stripper to remove the paint, and use this adhesive to bond it togeather: http://www.3m.com/3M/en_US/company-u...3241847&rt=rud
Its incredibly strong and used for structural components on many new vehicles. It can be welded through when uncured. So see if you can find a resistance spot welder. We had a huge and incredibly expnsive one where i used to work, but our equivilant of harbor freight has this: https://www.princessauto.com/en/deta...er/A-p8630196e
If you can find one that can also weld from juat one side that would be perfect.
Then use that panel adhesivw and some resistance spot welds instead of rivets.

I think your best bet for keeping these areas from moving however is a strut tower brace and lca brace that joins right and left side.

When acellerating the tire is pulling ahead wanting to pivot the lca. So at the mounting point here it wants to twist the front in towards the engine on each side.
So gluing and welding much heavier duty angle iron to the inside edge of the frame rail on each side, having it come ahead of the lca mounting point as far as possible, and then joining the right and left of the angle iron as far foreward as possible with a brace may work better.

But i think before this twists whatever your replacing the sway bar with has to fail...
And if this is a real problem a tube chassis is the more common fix.

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[william]

Haha you beat me to it.
I was gunna say used some panel bond like this and rerivet it back on.
New ultra high strength steel cars are held together by rivet bonding so why not .
It's also provides excellent corrosion protection


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[Doug Brown]

Thanks to both of you for the tip on the "glue". I do have some areas to work on where I can use it. You probably know, but the Festiva has many, many steel panels that are glued together and spot welded - or even just glued with a couple of screws to locate the part while the glue dries.

How you describe the movement of the front axle/wheel is what I refer to as "walking". This was a big problem with racing E-type Jaguars as the factory used a giant soft neoprene doughnut for mounting the rear trailing arms to the tub. A couple of us figured this out and depending on the rules we were racing under we made either visible mods or had to hide them (cheat?) It made a huge difference in the handling of the car getting rid of the "walking".

I have been collecting pictures of various types of shock tower "tie bars" and LCA tie bars so when the time comes I'll have some options to choose from.

I have also seen a couple of pictures where people have installed a tubular trailing onto the lower radiator support beam and have it connect to the LCA where the swaybar would normally go. This is my vague plan on how to do it at the moment...

Thanks for tips!

[Advancedynamix]

The problems with the sway bar walking have only been present with bad sway bar to chassis busings or when the narrow aftermarket poly sway bar bushings are used. It happens no matter what hp the car has. The sway bar has to be restrained from moving side to side (like good condition factory sway bar bushings do). It's the sway bar moving back and forth, not the chassis flexing. The area you are focusing on sees little to no stress under acceleration. It does see stress under cornering loads, but I've put extreme cornering loads on several chassis for long periods of time with no signs of fatigue. I rely on the flexibility of the uni body to help the chassis remain compliant. This is easy to feel when driving our caged car, that has lost a lot of the advantages of an uncaged festiva.
For straight line acceleration, that area of the chassis is not an issue. Adding weight to the car after the front axle centerline is an issue. The best way to get more traction and faster times is by reducing weight. If you reduce weight, you also reduce the amount of stress applied to the chassis. Less weight to tug down the track will reduce wheelspin. Weight isn't as much of an issue on RWD cars, because the weight transfers to the driving wheels with acceleration, but on a FWD car, weight pulls pressure off the driving wheels during acceleration.
Replacing rubber bushings with solid bushings in a driveline is not good for traction, especially when those bushings aren't seeing direct TQ load. Rubber bushings are important for absorbing harmonics and pulses that reduce the amount of TQ a car can apply to the driving surface. Wrinkle wall tires do a much better job than typical radial tires at isolating these forces, but dampening harmonics in the chassis will reduce the chance of fatigue in your driveline.

The TQ bearing structure of a Festiva is formed by the transmission cross member, front lower radiator support, axles, wheels and front sway bar. The struts see a small amount of TQ load during acceleration and a large amount during braking. The control arms see very little load during acceleration and a lot of TQ load during braking. The struts and control arms absorb the majority of the stress of cornering.
This information was formulated by observing control arm bushing failures in cars used for different types of motorsports. 300hp bpt Drag race cars don't seem destroy control arm bushings any faster than a stock festiva, but I can waste a set in 45 minutes on a road coarse in a stock b3 festiva with sticky race tires.