Pic from rear
I’m going to lower my 997.1 C2S with Eibach springs already purchased.
In preparation, I asked my Porsche Indy Alignment shop if he would
have any issues. His reply in an email was “rear toe links are useful
to ease alignment”. I would presume that he would mean ADJUSTABLE
rear toe links. Now, he is away so I can’t get clarification. Anybody
know which ones he would be referring to? By the way, in various posts
dealing with lowering springs on this forum and Pelican, I have not
come across anybody mentioning this issue.

TIA

Johan

 

I did put adjustable toe links from tarrett engineering when I lowered my car before.
it helped reducing tire wear. My rear tires worn out within 7K miles before the toe link adjustment and double that easily with adjustable toe links (back to OEM spec).

 

Yes, he means an adjustable toe control arm/link. This is so he can adjust the toe angle back to stock (or whatever setup you're looking for) as it changes once the car is lowered.

Here's a reference from Sharkwerks in regards to the toe control arm/link: https://www.sharkwerks.com/suspensio...-987-2-RSSS205

Here's another reference from Sharkwerks in regards to the rear control link / dog bone / upper control arms which they also recommend swapping out for lowered cars: https://www.sharkwerks.com/suspensio...models-RSSS204

 

Not required for Eibachs. The stock bits will get you the alignment you need. Do replace your strut mounts when installing the Eibachs. Lowering puts more strain on them and if they were old to start with they will give up ghost a few months after you put the Eibachs on, which means taking everything off again. Ask me how I know :-)

 

Did you change both rear upper and lower or just rear lower?
Johan

 

Many thanks for introducing me to Shakwerks.
Johan

 

Yes, new strut mounts on hand already but have resisted buying other potential replacement parts until I get in there myself. Did you do an alignment? Notice any change in tire wear?
Johan

 

I would think lowering the car would also mean you need adjustable drop links for the sway bars so that you can remove any preload from the bar that having a fixed length drop link would create. You're changing the relationship between where the body sits (swaybar attached to the body) relative to the attachment point on the suspension for the other end of the drop link.

 

this is probably true for aftermarket sway bars, the stock one is so flimsy I don’t think it matters.

 

With regard to sway bar adjustable or fixed drop links, I thought the bar could rotate in bushing J above diagram. So, as long as the links on the two sides were the equal length, there wouldn't be any preload. I know I'm missing something here - on some bars there's natural adjustablility because one can see the multiple holes on the ends of the bar (even in the diagram above). Maybe J bushing/attachment is a clamp... I have definitely bought bigger bars (for different cars) to overcome what RTL says.

 

The bars will rotate but are designed to work at a 90 degree angle to the drop link so rotating the bar and angling the drop link actually changes ithe forces on the bar as load is Joe being applied through angles instead of at 90 degrees, making the sway bar less effective.

These are the adjustable ones on my car, but you can see the geometry - same as in the elephant racing graphic in the first post.

 

Thanks Pete. So, it's not really preload that's being adjusted with the adjustable drop links but the "effective arm length". This article https://en.wikipedia.org/wiki/Anti-roll_bar illustrates it. By making the angle more or less than 90 deg, one is effectively shortening the arm length and therefore one should expect more anti-roll (but not necessarily the same balanced suspension, as designed).

 

I did the rear lower. We managed to get alignment to Porsche spec except camber. Best I could get with TechArt was -2.5 degrees. My tire lasted over 15K miles even with that camber with most wear on inner sides.

 

In most cases, that's correct, but having to rotate the bar can also create clearance issues with the sway bar to other components during suspension movement. You can also run into an issue where the sway bar won't swivel enough and you have to flex it to get the fixed length drop links installed. This makes the suspension behave improperly and is also how drop links end up bent when they get overloaded.

 

Camber doesn’t wear tires unless extreme.

Toe kills tires.