One of the first things we...
One of the first things we did to Project Laser was fit a set of 17x8 Motegi Racing TRAKLITE 2.0's and 225/45-17 Maxxis Victra MA-ZI tires. We chose our tires first and then figured out what wheels and springs would accommodate them. We needed the TRAKLITE's +45 offset for everything to fit right.
Most front-wheel-drive cars are plagued by understeer; some more than others. First generation Diamond Star owners know this. In stock form Project Laser exhibits some of the most classic displays of such poor handling characteristics. Now that our DSM's up and running, one of the first things we plan on doing is making it turn better.
Understeer happens while cornering, or when the car does everything it can to prevent the driver from cornering. Picture the car wanting to follow a straight line despite the curve ahead. It's the opposite of oversteer, but there's a more technical description for it. This handling flaw occurs when the front tires break away first in a corner. This pushing sensation happens since the front tires have a larger slip angle than the rear. The slip angle is the difference in degrees between the direction the wheel is traveling and the direction of the tire's tread caused by flex. In other words: it's the difference between the direction the wheel is pointed and the circle or trajectory the wheel is trying to track. This makes it difficult to steer into tight and/or high-speed turns. Most OEM's outfit their front-wheel-drive cars with understeer built in, since it's generally safer for inexperienced drivers in the event of a massive direction change. It just really sucks for the rest of us. Often times all you have to do to correct an out of control car with built-in understeer is let off the gas - good for the noob, bad for us. Oversteer requires steering manipulation, i.e., skill.
Reducing understeer isn't hard, but it's easy to screw things up in the process. A careful balance between what's done to the front of the car versus the rear must be taken. There are many things that affect steering characteristics: tires and wheels; struts, shocks and springs; even weight and aerodynamics. The first place to go looking for handling improvements should be the tires - the most important part of your car's suspension. Stuffing the widest tire possible into the wheelwell, and then fitting dampers and lowering springs around it, will get you the best results. To ensure the widest tire is chosen, careful measurements need to be taken. The easiest way to do this is to measure the clearance between the existing tire's inner sidewall and the closest thing it will hit, like a strut housing. Add to that half of the new tire's extra width and see what fits. Keep in mind though that just because a tire's advertised at 225mm wide, it might vary so check with the manufacturer first. Wheels with a reduced offset will space the tire out farther, allowing for its extra width. This is a careful balance though, since offset can disturb handling too and make a good car look stupid.
 The Maxxis Z-rated, directional...  The Maxxis Z-rated, directional tires are incredibly sticky and so far have made the most dramatic improvement to our DSM's suspension. Tires really are the most important part of a car's suspension. |  KYB AGX dampers and Eibach...  KYB AGX dampers and Eibach Sportline lowering springs replace our DSM's original issue suspension. The Eibach's lowered the Laser just over an inch and along with the KYB's did wonders for its cornering capabilities. |  Eibach also supplied us with...  Eibach also supplied us with a pair of camber adjusting bolts to dial out some of the negative camber associated with lowering the car. |