WARNING! Do NOT Proceed Unless You Know The Full Consequences Of This Modification!

By proceeding with this modification, you agree to hold harmless the person or thing that wrote this page (which you don't know, anyway).

I mean it! Do not do this modification without first upgrading your lame-ass H-rated tires to Z-rated or better!

I'm warning you! You really do not want to do this modification! Not only is it illegal to travel at this speed on any known public street, you could easily kill yourself when your crappy stock H-rated tires explode since they can't handle the heat! Change those damn tires now! Before you even finish reading this page!

Oh, by the way, technically, this modification is illegal, smog wise. It will not change the smog characteristics of your car very much at all, but any modification of your ECU without previous CARB or EPA authorization is technically illegal.

Hey! Who the hell is that? Is that your lawyer? Stop reading this page now, dammit!

How to remove the 130 MPH speed limiter from a 1995+ 2nd Generation FWD Turbo DSM

This modification has been proven on both a 95 FWD turbo and a 97 FWD turbo.


Because Mitsubishi uses H-rated tires on all of its FWD turbo DSMs, it must limit the speed of the car to 130 MPH just to be safe. 130 MPH is typically the safe limit of H-rated tires. Mitsubishi put Z-rated tires on the AWD DSMs. None of the AWD versions of the vehicle seem to have the 130 MPH speed limiter.

After changing to Z-rated tires and finding a nice private road course at which we can fully open the car up, we will attempt to make our FWD ECU into an AWD ECU.

Instructions - you must follow each one exactly!

  1. Change your crappy H-rated tires to Z-rated tires. They cost a bit more, but are well worth it. Your car will handle much better due to the stiffer sidewalls.
  2. Find a nice private road course at which you can fully open up your FWD DSM. You do NOT in ANY WAY want to test this modification on a public road! (Did you change your tires yet?)
  3. Remove your ECU. Instructions can be found somewhere else on the web.
  4. Open up your ECU. You should see a picture very similar to that found in Figure 1. It might be that your ECU does not have an EPROM and may be missing the large square chip. A 1997 ECU will definitely look a bit different in the lower left corner. Try to touch the metal case as often as possible to reduce the possibility of static electricity damage. Try not to touch anything on the board if you can avoid it. Best to play it safe.

Figure 1
  1. Locate the Configuration Resistors. They will be labeled R255 and R256. They will be standing perpendicular to the board (they are hard to miss). Even if your ECU looks different from this one, the resistors will be to the left of the white circuit board located in the center of the board.
  2. Write down whether R255 and R256 contain resistors. Save this piece of paper away, should you ever want or need to restore the ECU to its previous condition. By the way, did you make sure to change your tires to Z-rated yet?
  3. Change the Configuration Resistors to make your FWD ECU behave like an AWD ECU. It seems that the AWD versions of the car have both resistors set, while the FWD versions of the car have one or the other resistor set. To do this absolutely correctly, you would want to break out the soldering iron and add a 10k resistor. However, as it turns out, an AWD vehicle seems to be keyed either by having both resistors in or both resistors out. My sources tell me that in a 95 ECU, either both in or both out should act exactly the same way. On both the 95 and 97 trial, the resistor was clipped out, and everything seemed to work just fine. So you can take the easy way out and clip out the single Configuration Resistor that your FWD ECU has.
  4. Put your ECU back in and give it a try. If you have any problems, you can always restore your ECU to its previous state by replacing the resistors you clipped out with 10k resistors. You remembered to save the original configuration, right?

Written by somebody you don't know a long time ago in a galaxy far far away.