Sway Bar Drop Links

[North Coast Cab]

I needed to replace my rear sway bar drop links. Rather then spend $75 for an OEM set or $100 for an aftermarket set I decided to source and buy my own heim type drop links. Well after spending twice as much money I finally got a set to work.

Now my question is, how do I and do I want to preload the sway bars? I can adjust the drop links to be tighter and pull the bar up or I can make them looser and push the bar down. Which do I want to do and what is the end result? I would assume by preloading the effective spring rate would be higher.

Also, I've got enough parts for at least another set. If anyone is interested send me a PM.

John

[Zeke]

There is no sprung load on a sway bar. It is neutral. The only "loading" you can do is to weight-jack the car. You should keep it neutral.

What I'm saying is, there is no reaon to have two adustable links. One side is all you need. Install the first side and adjust the 2nd side to slip on with the car on level ground and rolled into place to settle the suspension.

The fact that you made up your own links is clever.

[89911]

I don't want to diminish your work, but youv'e made a nice set of adjustable drop links that aren't going to change anything from the stock ones as far a stiffness. To change the stiffness in the rear (and front) you need some way of changing the point were the droplink attachs to the sway bar. The adjustable drop links are a way of getting the same degree of stiffness on each side and making up for any deviations. The farther out from the fulcrum, the less torsional force. Perhaps there is a way to alter your stock ones? Better yet, John, youv'e come this far, why not build a new bar and arms yourself. You do nice work!

[North Coast Cab]

They are the later style Carrera bars 21mm vs 18mm in the rears. I really wasn't looking to have a project to stiffen the rears, I just needed to replace my worn out drop links. Anyway, I guess I don't understand why I couldn't tighten the drop links equally on each side and thereby preload or prestiffen the sway bars. Either way the heim drops look much nicer.

John

[TerryH]

I'm working on my sway bar too, but replacing with oem parts. Looking at your links, is there a jam nut there to lock the pair together or will the threads be expected to hold by themselves? Once adjusted/set, I would think a jam nut or even welding would ensure a longer lasting marriage of those two pieces.

[North Coast Cab]

No jam nut now, but thinking of shortening each end to allow for one. There is no way for them to really turn or loosen so I'm not sure it's necessary.

John

[Randy Webb]

Springs provide a constant resistance (the spring constant). You won't alter the stiffness by doing this. You might limit the amount of movement available tho. (a bad thing).

[Zeke]

Originally posted by North Coast Cab
Anyway, I guess I don't understand why I couldn't tighten the drop links equally on each side and thereby preload or prestiffen the sway bars. Either way the heim drops look much nicer.

John

Maybe I don't understand what you are thinking. If your sway bar is in the car and no links are attached, you should be able to move it up and down, the friction of the bushings being the only resistance. It is a free floating device. Connect it and all it does is move the weight back to the light side by forcing the light side to somewhat follow the movement of the heavy, or outside wheel in a turn. The amount of weight transfer is adjustable as 88911 describes.

[911pcars]

Unless you're cornering in one direction (ala Nascar), you will want your car to handle equally well both left and right. Therefore, you should install the sway bar so there is no preload on either side. Minimally, one drop link works for this purpose.

Although you may not have increased the roll resistance (since the distance from the drop-to-sway bar remains the same and you haven't increased the bar OD), if you corner balance your car, the adjustable links will allow slightly difference individual corner heights (the rear anyway) to arrive at a "balanced" chassis without introducing any suspension preload - impossible with fixed-length drop links.

The length of the new drop links doesn't have to match with the factory ones. You should be okay as long as the angle of the bar ends is close to perpendicular to the drop links and you have adequate road clearance. A thin jam nut might fit if you have to shorten them more.

Hope this helps,
Sherwood

[rattlsnak]

I used the same setup for my 993, and it worked fine. No preload on the bar when flat on the ground.

[Elombard]

Sent you a pm on the spares!

[Schrup]

I attended my first DE a couple weeks ago. My instructor (Randy Wells) drove my car a few laps & he mentioned that I had all the right components for a good suspension, but he felt that they weren't working together properly. After reading this thread I think I may need to unattached my adjustable links from my sway bar & adjust them so I can reattach them while the car is sitting on the ground.

When he first mentioned the car felt unsettled in the rear, I accredited to my rear tire pressure (40psi), but he felt there was something more to it so maybe this will be it. When I installed them I set them at the middle of their adjustment with the car on jack stands. I haven't driven any other 911 but my own & it feels much better with the new suspension I installed last winter. The car has a lot less under steer & stays really flat while cornering.

I plan to make this change tonight & will be curious to see what Randy's assessment is at the next DE. He will be my instructor again & can push the car a lot closer to it's limits on the track than I can. I want a good base to start to learn on before I start to make adjustments for my driving style after I learn to drive on the track. Perhaps after a while I'll get some adjustable sway bars after I learn to drive, but I don't think I want a tail happy car in the meantime. Thanks for the good input.

[North Coast Cab]

Paul,
Are YOU supposed to drive the car during the DE?

John

[jpnovak]

Just be aware that you should have the conical washers to go with those spherical rod ends. Otherwise they might bind. The binding is not a problem for your application but will affect lifetime of the part.

That combination works well but I would suggest a locknut or loctite.

Everyone is right, no preload on the bar. To stiffen you will not change the length of your drop link. You will just move the drop link closer to the pivot point.

[Schrup]

Originally posted by North Coast Cab
Paul,
Are YOU supposed to drive the car during the DE?

John

John, I drove my car plenty, I thought it was a good idea to get some input on how my car felt from someone with a lot more experience. I want a good neutral base to start from & don't know what a neutral handling 911 is supposed to feel like. My next DE I should have a better idea as I think I preloaded my sways. I just want some reassurance that "yes this is how it's supposed to be", then I can go from there on what I like which very well could be a tail happy car because I hate under steer.

[Schrup]

Well I just got through readjusting my drop links. I unbolted them from the sway bar then drove the car around a little to resettle the suspension. I had to extend them about half an inch to get them to line up with the sway. There is only about three turn out left on them. After, I drove around a little but couldn't push it. My first impression is that the back end is less stiff.

My question is why would Pelican & moreover Tarret market these if they are worthless. My next step may be to drill some more holes in the sway, but then again I don't want to devalue them because if I upgrade to fully adjustable sways I'll probable want to get my money back out of them, about $250.

[North Coast Cab]

Paul,
What year car do you have and what type of sway bars?

John

[Elombard]

Paul are you sure you did it right. Can you adjust both of them up about half way and still have no tension?

[911pcars]

Paul,
I assume you have a fully adjustable Tarret sway bar; adjustable drop links and adjustable sway bar arms.

Perhaps a drawing or photo describing the current setup would be more descriptive. Ideally, the geometry should be such that the drop links are close to vertical when installed midway through the total adjustment. That way, the drop links don't sit at an acute angle if the arm length is at full hard (short arm) or full soft (long arm).

IMHO, three threads is not enough engagement.

Sherwood

[Schrup]

John, I have a 80 SC & I upgraded my sway bars to the larger Carrerra sways 22/21mm.

EW, I put the car on jack stands to unbolt the drop links from the sways & when I put it back on the ground, the holes still lined up. That is why I took it for a drive without the sways attatched to see were they would settle. I couldn't push them any higher by hand, so I figured that is were my drop links needed to attach.

I'll take the car out tommorow for a spirited run to see how it feels under hard cornering.

Sherwood, I only have the adjustable Tarret drop links on the rear.