Originally Posted by djpathfinder

Lowering springs for looks and coilovers for performance.

I have Tein MonoFlex coilovers and did a "mild" drop...3/4" in the front and 1/2" rear. I also go to the track once or twice a month in the summer time. From the reading I did on this forum, it was speculated that a drop of less than 1" didn't require camber kits. I can tell you first hand that this statement is false. If you don't mind your camber being a little out of spec, I suppose you could let it slide. It's my experience that even with the mild drop that I did, along with the use of spacers, my camber was enough out of spec that I decided to go ahead with installing camber kits.

Front camber is not adjustable with the stock upper control arm. If you want/need to adjust the front camber after lowering (e.g. reduce negative camber to bring back to spec or increase negative camber to improve turn in response at the track) you'll need to buy a front camber kit. For our cars, it is a replacement front upper control arm.

In the rear, negative camber as a result of lowering can be brought back to a certain degree with the stock components. I think they were able to bring my rear back to -2.4 degrees (from -2.9) without a camber kit. Nissan recommends up to -2.2 degrees, so in my case there was a 0.2 deg difference...not too big a difference. However, I wanted my final camber in the rear to be -2.0, so I opted to get both front and rear camber kits (SPC). Make sure you get the rear kit with camber arms, not just bolts only. This allows for greater adjustablility.

You could do a wheel alignment after installing coilovers (wait 1-2 weeks to allow the springs to settle first) and see how far out of spec you are before deciding whether or not you want/need camber kits. However, in my opinion if you're going to bother getting coilovers, you might as well do it right and get the camber kits done as well. That way you can adjust your ride properly, front and rear. In fact, I also recommend, if you go to the track or do autocross, you should get your car corner balanced after the spings settle. Corner balancing and wheel alignment can be done together. Corner balancing fine tunes your suspension so that the cross weights (FR + RL = FL + RR) of your car are the same, and thus the car will respond the same while making left hand or right hand maneuvers. This is something that needs to be done once so long as your ride height is not altered...anyhow, that's some more food for thought for you.