Lowering Springs, Dog Tracking, Adjustable Panhard

[ward00]

How have any of you dealt with dog tracking (back of the car gets shifted relative to the rear of the car) that occurs when installing lowering springs?

I only learned about it because friend who was driving behind told me he saw my spider driving slightly sideways after I installed the lowering springs.

Lowering springs change the suspension geometry, which cause the panhard rod to push the rear of the car out relative to the front, which in my case was about a 1/2 inch.

I'm surprised that this negative side effect of lowering springs has not been discussed more (if at all) on this forum or that any of the vendors do not sell a solution in the form of an adjustable panhard.

[ward00]

Crickets on what I thought would bring spirited discussion like it did on https://www.mirafiori.com/forum/viewtop ... 15&t=98735. Posting the link to document the issue for posterity.

[aj81spider]

I read the Mirafiori thread, which was interesting. I also did the math and got the same answer mentioned in the thread (7 MM horizontal displacement) assuming a 2 inch drop (and making some other assumptions, like a 100 cm panhard and a 15 cm (about 6 inch) drop from the panhard mount to the axle).

7 MM is about 1/3 of an inch. If someone driving behind you can see the displacement I suspect that it's more than 1/3 of an inch. If you have old or soft bushings the 1/3 of an inch might even get largely absorbed by them.

While an adjustable rod would let you take out the 1/3 of an inch - it's not much of an adjustment for the investment. I agree with the Mirafiori commenters that you should look for something else going on.

[18Fiatsandcounting]

Thank you for posting the link for posterity. I too followed the discussion on Mirafiori, but since I've never done anything but stock in terms of suspension work, there wasn't much I could offer.

-Bryan

[DieselSpider]

Yes in theory this does happen however it also works the same when you load the trunk to its max capacity of 140 lbs and when you put a passenger in too.

The front suspension also goes between radically toed out to insanely toed in when you go over humps and dips in the road which can cause the tires to chirp very loudly.

These are the major reasons why the cars are supposed to be aligned when laden.