Lowered front, knocking sound

[Styleprojekt]

We just installed H&R sport springs on my friends B7 S4...and now when he hits little dips there is a knocking sound as if something was hitting the car from underneath. We tightened/double checked EVERYTHING 3 times...

ANY suggestion what could have happened during the installing process?

Im so clueless and frustrated

[khyber]

I had a knocking sound after I lowered my car and I think it was the CV joints or something of the sort. I'll double check the receipt tomorrow and repost.

[AudiOso]

Check the torque on the sub-frame bolts.

[poopypants]

Check your upper strut mounts/bearings. Probably bad

[Styleprojekt]

Thanks for the replies guys.

We didnt mess with the subframe so nothing there could (should) be lose.

Im gonna check the upper strut, i was thinking it must be around there the noise is coming from but didnt know for sure...

[ieatfishburitos]

Check your control arms. My were toast when my coilovers were installed. That little bushing thingy could be loose and moving around?

[trexturk]

this may sound stupid, but check the exhaust downpipe?
it may be hitting that subframe.