With the Z1 undershroud, is the ground clearance affected in any way? Would it limit the ability to slam the car with air suspension?

Assuming car is decently low on coilovers, do you just ride around scraping loudly on everything once you have this installed? As far as I can tell the only thing I ever scrape a little is my bumper, except for a very steep incline I have to take in which I slightly scrape the underneath of the car if I don't take it at the perfect angle.

 

Not any lower than the stock plastic.
It installs 1/4" higher even, because it can support its own weight.
You can run just the front half to hold up your front "bumper".
​​​​​​Use self tappers or nutserts on the aluminum crossmember.

 

^^^What he said.

When I installed my TBW last year, I had the distinct impression that it actually improved clearance a little bit, because the aluminum runs flat under the cross-member.

 

I know this is a thread from Spring of 2021, but It ranks high on Google so I wanted to update it so any future viewers of the thread have another perspective on the Z1 Undershroud and associated clearance issues.

Essentially, I installed the Z1 undershroud on my 2013 G37S Sedan (Lowered on Swift Springs with Stock 18 inch Sport Wheels - "Duckfeet") yesterday, but it was late when I finished so I didn't get to fully test drive. Install went well using their instructions, but if you have never used a manual "riv-nut" tool, you may want to watch a YouTube video showing how riv-nuts work to get a better idea of how to use the tool (instructions just say "install riv-nut using tool provided" basically) they provide. Also, pay attention to their advice to not tighten anything down till the very end.

As for the test drive, this morning I decided to take my car through the soccer mom circuit of elementary school, Costco (tallest speed bumps I've experienced in CA), steep entry/exit grocery stores, Baseball fields and HOA enforced speed bump rich parking lots that I know for a fact are problematic based on my experience prior to the new undershroud.

Unfortunataly, I don't think any clearance was gained with this mod. It seems that speed bumps and steep entry/exits that I used to barely clear just fine with the "one wheel at a time" approach, are now slightly problematic and drag slightly with the new Z1 shroud. If you look at the photos I attached below, I think the problem lies in the fact that the unit has sharp right angles as edges and those edges seem to be whats dragging (I inspected when I got home). Note that the dragging is slight (but loud because it's aluminum vs plastic), so if you can live with scratching/rounding of those edges a little, you should be fine.

I also observed that there is more noise coming from the underside of the car as small debris and stones bounce off the aluminum. In addition, the front of the car feels more rigid, almost like a second strut bar was installed. Maybe this is my imagination?

Overall happy with the product. I just need to be even more careful and doubt I can ever let my wife or 20 year olds drive the car for fear that they will tear the thing off...