JimStim - The Megasquirt Stim with a Wheel Simulator


JimStim v1.0 Board

This is a new version of the stimulator originally designed by James Murray (jsmcortina on the forums) that expands on the original stim's features. The main improvement comes with the addition of a microcontroller which allows the simulation of up to 30 different toothed wheels in addition to the standard distributor signal of the old stim. At the moment, there are 28 programmed wheel patterns but the firmware is upgradable using a specific USB cable made by FTDI (see BOM: v1.5, v1.4, v1.3 or v1.0 and v1.1).

The thread discussing the board can be found here.

The schematic for the v1.5 board is available here.

The JimStim v1.5 now comes with a new firmware version: the V2.0 firmware. The CPUs programmed with this new firmware version are identified by a sticker which indicates the version number (currently V2.0.3). This firmware works with all JimStim board versions.

JimStim v1.5 Assembly Instructions

JimStim Firmware v2.0

Connecting the JimStim to the MicroSquirt

The schematic for the v1.4 board is available here.

JimStim v1.4 Assembly Instructions

JimStim v1.4 Setup

The schematic for the v1.3 board is available here.

JimStim v1.3 Assembly Instructions

JimStim v1.3 Setup

Assembly Instructions (v1.0 and v1.1)

Wheel Simulator Setup (v1.0 and v1.1)


The JimStim is only available as a partial kit which includes a board and a programmed CPU. The partial kits are available at US$28 per partial kit plus shipping. Shipping for up to 2 partial kits is US$4.50 in North America and US$6.50 in Europe. This is for regular mail from Canada. v1.5 boards now available
Please note that regular mail service to the US has been quite irregular. The delivery time has been from less than 2 weeks to more than 4 weeks. If this is not acceptable, you can request Xpresspost service which will speed up delivery but will cost an additional US$12 more. Email me for details.

I only accept Paypal.

You can contact me through PM at the msextra forum where my user name is racingmini_mtl
or by email: boards at jbperf.com

NEW! The JimStim is now available from DIYAutoTune as a complete kit and fully assembled.