One question we keep getting goes something like “how much is SD” or “what do I need to run SD”.

First, pricing information is listed on our website. So that one's easy.

But to figure out what to order, you have to consider a number of different configuration options. This page attempts to list these out in a “walk-through” layout.

The simplest choice to make is whether you want to run an IAT sensor or not. Many people run without an IAT sensor at all simply because they either don't want to install one or they actually want the mixture to run a little richer as air temps increase or they want to use the IAT input to log something else.

Obviously you lose the compensation you would normally get at full throttle with an IAT, but that usually just results in a richer mixture as air temps increase anyway. So it's not always a bad thing. You just have to remember that this compensation isn't taking place and expect to see lower (richer) A/F ratios at the end of a hard road course session than you were seeing at the start, for example.

You disable IAT compensation while running SD by setting the SDTempWeighting table in direct access to all zero. This removes IAT compensation while retaining basic coolant-based compensation.

If you choose not to run an IAT sensor, then you only need a MAP sensor to run SD. We have two MAP sensors available on our website: GM-style or Mitsubishi-style. Both are the same 4-bar sensor internally, so there's no decision there.

If you're running a GM-style MAP with no IAT sensor, you'll still need to decide how you want to wire the MAP sensor into your harness. You can use our SD Cable if you want a plug-n-play solution. You'll just leave the IAT connector unused.

Or you can wire the MAP sensor into the wiring harness using our pig tail. The red wire goes to +5v, the black wire goes to sensor ground and the blue wire goes to whichever ECU input you've chosen for the MAP. The most common is the baro input, but that depends on a few other decisions like whether you're going to retain the stock MAF while dialing in the SD VE table. Pin out information can be found on our ECU wiring information page.

The Mitsubishi-style MAP plugs directly into your 2G MDP harness connector. The MAP sensor bolts onto the intake manifold in place of the factory MDP sensor. So make sure you're either running a factory 2G DSM intake manifold or that your manifold has been adapted with this flange.

If you choose to run an IAT sensor, then you need to have an IAT bung welded to your intake pipe. The typical installation point is in the throttle body elbow. You'll need to specify the material type of this bung to match whatever your intake pipe is made of (steel or aluminum). Also make sure the IAT bung is installed properly. Because it's a tapered thread, it can be installed upside down! You want the tapered end of the threads to be installed towards the inside of the piping.

If you're running a GM-style MAP and the IAT sensor, then the most obvious choice for connecting these to your car's wiring harness is to use our SD Cable. That will plug directly into your car's MAF connector on one end and then into the MAP and IAT sensor on the other.

Or you can wire the MAP sensor into the wiring harness using our pig tail. The red wire goes to +5v, the black wire goes to sensor ground and the blue wire goes to whichever ECU input you've chosen for the MAP. The most common is the baro input. Pin out information can be found on our ECU wiring information page.

For the IAT sensor, you want one side going to sensor ground and the other side going to the ECU's IAT input.

The Mitsubishi-style MAP plugs directly into your 2G MDP harness connector. The MAP sensor bolts onto the intake manifold in place of the factory MDP sensor. So make sure you're either running a factory 2G DSM intake manifold or that your manifold has been adapted with this flange.

The IAT sensor will need to either be wired directly into the wiring harness or you can consider using our SD Cable if you want. If you use our SD cable, then you'll just leave the MAP connector unused since your Mitsubishi-style MAP will plug into the factory MDP wiring instead. If you decide to hardwire the IAT sensor, then you'll want one side going to sensor ground and the other side going to the ECU's IAT input. Pin out information can be found on our ECU wiring information page.

There are so many different ways to setup SD that it's a little crazy sometimes.

For example, you could already have a MAP sensor and just want to install the IAT sensor. In this case, you might want to hard wire it or use the SD Cable anyway.

Or you might already have a GM MAF cable and just want to use the break out points already provided with that. And, again, this could be with or without an IAT sensor too.

Or you might want to retain your factory MAF sensor temporarily while dialing in the SD VE table with the MAP (either temporarily or permanently) connected to an input other than the baro so that you can retain MAF operation.

So it's crazy to try to document and support every single possible combination that comes up. At some point, you have to step back, learn and take in all the options and put together your specific plan of attack.