Front ride height sag

[AA-ron]

Hello everyone,
I finished my build this past June, so the car has basically been sitting on it's wheels since April. I adjusted my ride height to 4" in the front and 4-1/2" in the rear. In June before I had the car aligned, I noticed that it had sagged around 1/4 inch on all four corners (plus/minus 1/8"), which I assume is normal. I raised it and had it aligned and all good. I was just doing some tinkering on the car yesterday and I noticed the front has dropped about 1/2" since June, effectively putting me at 3-1/2". The rear has held tight at 4-1/2".
My question is, does this seem normal? I realize the spring rates are different between front and rear, so I'm not surprised they don't sag at the same rates. I guess I'm a bit surprised to see THAT much sag in the front. I'm just curious if others have experienced the same thing. Not that I'm really that concerned, as I'll raise it to the proper ride height again, thus returning things to the correct alignment-- I'm just curious to see if this is normal.
Thanks

[AC Bill]

It's expected that the shocks/springs wouldn't settle completely until at minimum, the car was driven fifty miles or more. Just sitting parked will not work.

[Mark Reynolds]

Not normal. Springs don't really sag. Change in Tire pressure more likely I think.

[Jeff Kleiner]

I agree with Mark. Of all the cars I’ve done I have never seen ride height change after moving the car forward and back a few times to assure that the springs are seated and the tires have been able to roll flat.

Jeff

[rich grsc]

I have never had my ride height change enough to bother with readjusting.

[AA-ron]

Hmmm... well I was hoping it was a standard thing to see sag like this. One thing I didn't take into account was a change in tire pressure. It was very cold in my garage the other day when I measured the height (18 deg) so possibly the lower tire pressure is accounting for some of that sag. My next step it see if the height adjustments on the coilovers moved a bit. I marked them when I set the height the last time so it's an easy thing to check. Although it seems odd that they would have moved as I locked them with the set screw.
I'll investigate deeper into this and report my findings.

[CraigS]

Yep, 1/2" is not normal. Could be bad springs but that would also be very unusual. I'd just crank it back up to your normal height on move on though. What else is there to do?

[AA-ron]

Yep, 1/2" is not normal. Could be bad springs but that would also be very unusual. I'd just crank it back up to your normal height on move on though. What else is there to do?

Yep, exactly my plan!

[Railroad]

Are you measuring on the same floor at the same location? Some floors have crowns or valleys.

[Jeff Kleiner]

... Although it seems odd that they would have moved as I locked them with the set screw.
...

When I build a car those set screws go in the round file. Even with the plastic tips they can damage the threads on the aluminum sleeves. This photo shows a customer car that I had to fight with for probably 20 minutes with a strap wrench and adjusting tool to get the collar turned off of the damaged area. And it wasn't the first one I've had to have that fight with :mad:

https://thefactoryfiveforum.com/attachment.php?attachmentid=195237&d=1706888051

Once the spring pressure is on the collars they don't move---the ones on my own car haven't changed in almost 17 years and 30K miles. Lock 'em down if you wish but be forewarned.

Jeff

195237

[AA-ron]

Well I just figured out my problem with my "sag". And Railroad, you hit it right on the head! I'm embarrassed to admit that when I took the measurement last week, I was parked in my wife's spot in the garage instead of the "cool guy" spot. I took a look at her parking spot and found a significant crown, or rather I should say, depressions where the tires sit. And yep those depressions were enough to change my measurement by close to 3/8".
I still amaze myself that I was able to build a car that works when simple things like this occasionally throw me for a loop. :)
I'm sorry I wasted the Forum's time on this-- live and learn I guess.
Jeff, regarding your comment on the set screws dinging up the threads, I did manage to see that one coming and swapped the steel set screws for nylon ones. I'm not sure if they help at all, but it's nice to know that we don't rely on them much to hold things in place.

[CraigS]

AA-ron no problem on wasting our time. We have all made what feel later on like boneheaded moves somewhere along the line. BTW I am also in the trash the set screws camp. One other tip re; height. Count the number of threads exposed beyond the adjuster collar. It should be the same left and right sides at the front and also L and R at the rear. Front and rear will generally be different.

[phileas_fogg]

Man, if I had a dollar for every question I asked that had an embarrassingly easy answer, I could buy another Roadster! (As could every other builder on here).


John