Its fairly easy to increase the angle on an S30 using the stock components. There are 4 things that you can do to increase the steering angle. You can shorten the knuckles, modify the inner tie rod, and fabricate or buy new lower control arms (LCA). Depending on your wheel/tire size you may need to remove the inner fender in front of the shock tower and you may need to cut out a portion of it behind the shock tower, I needed to do that.
Requirements for 40 degrees
If you are looking to get a modest amount of angle you must have a tubular front end, unless your running some crazy -offset wheels with spacers and some kind of crazy body kit/flares. You will also need lower control arms that have the tension rod incorporated into them like mine, the wheel will rub up on stock or aftermarket LCAs with the OEM design tension rods.
To modify the steering rack you remove the metal spacer and cut the extra threads off of the inner tie rods. Leave the lock nut because the inner tie rod likes to back out if you remove it.
The end of the rack should look like this when its all done. I have been using my rack like this for over a year with no problems.
To shorten your knuckles just remove them from the car, put them on a miter saw, cut a portion out of them and TiG weld them back together; you can MiG weld them but the bead is going to be much bigger and you will need to grind the face of the weld down which will compromise its strength. I cut mine 18mm, they weld very very nicely. Also make sure you weld them both the correct direction, take a picture of them before you cut them.
Lower Control Arms are needed because the stock ones are too wide and cannot be adjusted, the outer tire rod ball joint or heim will hit it and bind the suspension causing you to spin or have other problems. I fabricated mine using DOM tubing with high quality heims. The rub marks were caused by a set of tires I was using, they were too large, I changed to a smaller size.
