Brake Time - Garage Tech

Most articles about brake upgrades begin the same way. Someone starts off telling you how important stopping is and how installing bigger and better brakes once horsepower's been increased is a good thing. It is. But we'll take things a step further. Install that big-boy GT turbo and crank up the boost without addressing your cheesy rear drums or chunked-up rotors and, well, let's just say nobody's going to mistake you for somebody smart. And while no one's accusing us of being smart, early 1G DSM big-brake upgrades just make sense.

The Problem
Diamond Star Motors realized a few improvements were in order for the first-generation Eclipse, Talon and Laser not long after they started selling them. The '90 model's ECU only survived one year before they replaced it. Someone decided to change the cam angle sensor in 1991 also. And the DSM boys figured slightly better braking was in order for some models come 1991 and again for others in 1993. Well at least nobody can blame them for not paying attention. There are two things that suck about the '90-'92 front brakes: they could be bigger, and they're a single-piston setup.

The Solution
As with a lot of things, the solution lies within the OEM itself. Since Mitsubishi didn't mess with the hubs when upgrading, swapping over the slightly larger '93-94 DSM brake setup is relatively easy. But first, here is why they're better. The newer rotors are larger, measuring in at 10.9 inches across as opposed to 10.1 inches-almost an inch. Of course this allows for additional swept area for the pads, 22 percent to be hard and fast, making braking easier and more effective. The '93 brakes also feature twin-piston calipers while the older pieces are a single-piston configuration. It's the pistons that react against the pads once pedal pressure's applied; the more pistons, the less pedal effort and, again, more effective braking.

Where to Get Them
No, there aren't a whole lot of '93-'94 DSMs floating around with decent front brakes that also happen to be for sale. Face it, the car's old. We have. Fortunately there are a few unexpected cars we can rob such brake setups from. The '91-plus non-turbo Dodge Stealth and Mitsubishi 3000GT come to mind first. Yea, the turbo ones are huge but they don't fit. And then there's the '91-'92 Galant VR-4 and the '92-'96 Diamante, which also both have the same twin-piston, 10.9-inch front brakes. About the only difference between any of these are the different bleeder valves between some models, which means nothing more than you're either going to grab an 8mm wrench or a 10mm one when you go to bleed them. Oh, and you'll also want to watch out for some of the 2G DSM calipers that feature a banjo bolt provision as opposed to the female-threaded ones you need. Even if you score the wrong ones the added work isn't worth the effort.

How it's Done
Like we said, new-condition rotors, calipers and pads from the early '90s aren't exactly easy to come by. As such, we weren't surprised when our eBay pieces arrived; the rotors were warped, of course the pads were shot but fortunately the calipers were in good condition, which is really all we care about. EBC brakes helped us out with the rest. Up front we swapped over a pair of EBC's Ultimax BlackDash USR slotted rotors. Slotted rotors are good because they help remove debris from the braking surface, but slots often lead to noisy stops. EBC's progressive angle and slightly smaller grooves keep the noise down and are designed to keep pad wear as flat and parallel as possible. It's a good thing the older DSM's brake dust shields clear the larger rotors...barely; this prevents us from having to yank the hubs off.