Trailing arm stiffeners.......... Options

[Marv's3.6six]

:............. Are they needed? I notice on Patrick Motorsports big engine 914 cars none are used. Any high HP cars here runnin them?

I have a set in the box, and all the susp components are coming off the car in the next couple weeks as she will be painted on a rotissere.

Opinions wanted! (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif)

[Aaron Cox]

difference of opinions in these.....

some say that they are needed...others say they arent.
some say the trailing arms flex...some say they dont....

think of it this way - if you spank a curb etc, what would you rather break - a BOLT on trailing arm, or a welded in suspension pickup

(IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

[dakotaewing]

The typical opinion here is that you would rather replace the arm than the ear it is attatch too.... 2-4 hours verses 16-20

TE

[Joe Bob]

IF ya do it...make sure the arm is in a jig....they will twist and make alignment a bitch. BTDT....

Also...I wouldn't consider anything that Patrick does as gospel...those guys are morons....

[ArtechnikA]

they are a historical artifact.

the factory tried a LOT of things to eliminate flex, and unsurprisingly the 914's didn't get a lot of full engineering support (they were kinda busy winning Le Mans and the World Championship of Makes with the 917's). so they just tried a lot of stuf. they tried stiffening the trailing arms. before long other people copied the factory stuff.

if you are trying to build a historically accurate GT clone (museum piece) i suppose there'd be a place for them. contemporary wisdom is that they do nothing useful. they weigh something (unsprung at that...), they cost something, and they strengthen a part that you're better off bending that using to transfer exessive stress to the tub.

"it seemed like a good idea at the time..."

[Marv's3.6six]

"it seemed like a good idea at the time..." Thats the way I am leaning, not using them

Also...I wouldn't consider anything that Patrick does as gospel...those guys are morons.... I know you have that opinion of PMS Mikey, but my experience with Jim has been outstanding.

The typical opinion here is that you would rather replace the arm than the ear it is attatch too.... 2-4 hours verses 16-20 So yur saying no to stiffening the arm?

think of it this way - if you spank a curb etc, what would you rather break - a BOLT on trailing arm, or a welded in suspension pickup So Aaron are you saying no to stiffen?

I have put alot of time, energy and $ into chassis, body, and suspension pickups stiffening and gusseting, some stuff that has not quite been done before, or at least that I have seen, my metal guy is a hot rodder thats a suspension guru specialist.

[Joe Bob]

Yeah....I keep dissin' them and it's prolly gettin' old, but I'm not the only one that has had problems with them...just the most vocal.

I've done the arm stiffener once...they twisted because I was not aware of the problem...and I have a set that someone else did that seem straight. The idea of a sacrificial bend as opposed to the ear taking a hit is a good thought......"I" wouldn't do it again.

[Aaron Cox]

IMHO - leave em off

[J P Stein]

I probably put more stress on my suspension in a weekend than most guys do in a couple years due to our gawd awful
rough AX venue....how rough you ask?

It's not unusual to have 2 front or rear tires off the ground every pass. I saw a bad combo of bump/off camber turn have a guy up on his drivers side wheels at about a 20-25 deg angle.....and the traction isn't that good. Another guy's drivers side front suspension collapsed at our last SCCA outing....rice reeks (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

I have none of the fashionable "stiffening kits" on the car....cept a good cage and a lot of seam welding. I've been beating on the car for 3-4 seasons and nothing has broken. I have no rubber in my suspension except upper rear shock mounts. When it breaks (not if), I'll let ya'll know.....I thought I hurt the motor last weekend.....but I was out of gas (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

[Marv's3.6six]

I have none of the fashionable "stiffening kits" on the car....cept a good cage and a lot of seam welding. I thought alot about a cage and just could not do it, it crosses a line that sez full on race car, plus I don't like the looks of a teener thats caged. My metal guys and 914 mechanic ace Tom feels that with all the stiffeners added, the car will be purty good about not twisting up during AX, we'll see.

Thanx for all the replys (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[IronHillRestorations]

A friend of mine who is a 914'er and a aeronautical engineer did a computer model study on the 914 rear trailing arms and found that welding those stiffeners may actually weaken them.