I just picked up the Ireland E30 adjusters. They are nicely made, however I feel there are some design flaws with them in at least when used on the ti. I assume it would be an issue on the E30 as well.
I'll start by showing the ride height. This is using 950lb 5" hyperco springs. The adjuster is set to it's lowest position here and the urthane insert is also installed. This also has a Bilstein shock installed so there is some additional stiffness due to the gas charge. A softer spring rate would obviously put the car lower.
My main concern is that they limit spring travel. The adjuster would first make contact with the urethane isolator with a spring length of 3.25". You could look at this as a bumpstop, but at 3.25" on a 5" spring, you only have 1.75" of spring travel. A 5" hyperco spring can be compressed to ~2.25" in total height before spring bind and about 2.6" is considered the limit to the usable stroke. The height adjuster is eliminating about .75" of usable travel in the spring. With the suspension motion ratio, this is almost 1.5" of additional wheel travel. As a fix, I have cut the height adjusters down to allow full spring bind before contact with the spring isolator is made. I will rely on the shock bumpstop to limit travel and not the spring perch. I could see a valid arguement for using the spring perch as a limiter though as really, the spring is meant to carry more load then the shock mounts.
At the very least, I'd consider cutting down the adjusters to increase travel some amount while still functioning as a bump stop before running the spring mounts into each other. Realistically though, you probably have bigger issues by that time though, as here is where that puts you.
Buying rear adjusters and springs 
Linear Mode
