#$2011

Last update on last years setup... These last few photos show some of the early stages of fabricating the exhaust piping from the turbo.  The exhaust was put together using some scrap 4" aluminized tubing picked up from a local truck shop.  We cut off the Holset exhaust flange from the stock dodge pipe and shaped the 4" pipe to match.  The cheapest and easiest (and most awesome if I do say so myself) solution for exhaust given the amount of tubing we had to work with was to go straight out the hood.

One of the most time consuming tasks in preparing the car last year was assembling the Megasquirt.  As I mentioned earlier we purchased Megasquirt II kit from DIYautotune.com.  The kit came with the bare V3 board, a bunch of parts, and the MS2 processor.  We also bought the extra coil drivers and resistors needed (standard MS comes with one coil driver) to run the GM wasted spark setup.  After countless hours of soldering we had a brand new, cheap, highly configurable engine management system.  Wiring was simply a matter of connecting the various sensors, injectors, and coils to the appropriate pin on the DB37 connector.  An additional DB9 connector was added for the coil outputs.

We modified the stock BMW M20 throttle body for use with the Megasquirt setup.  The body was tapped 3/8 NPT to accept a GM open element intake air temperature (IAT) sensor that we sourced from a local junkyard.  The stock throttle position sensor (TPS) was swapped out with a TPS from an E36 to provide a good analog throttle position signal.  Finally, all unused ports (idle air control, etc) were filled with a combination of bolts and JB weld... which amazingly turned out pretty well.

More updates on last years car...  The coil pack we used came out of an Isuzu (it's a standard GM 6 cylinder coil pack).  The circuitry was gutted and replaced with simple wiring as ignition will be controlled by the Megasquirt.  The stock injectors would not be able to keep up the required fuel for our target power so we picked up some much larger capacity injectors used from Racingjunk.com.  We then modified the stock wiring harness to adapt it to the Megasquirt, like the stock setup they are fired in batches of 3 cylinders.

After removing a bunch of weight from the car, it more closely resembled a 4x4 than a racecar.  To remedy this we decided to modify the stock front struts and simply replace the rear springs with shorter stiffer rear springs.  The cheapest way to accomplish this was to purchase a sleeve style coil over kit intended for civics from Ebay.  We then cut the stock spring perches off and welded on a small piece of steel pipe to hold the sleeve.  At this point I can't remember what spring rates came with the kit but they were not nearly stiff enough.  We'll remedy that for 2012...

Photos of other interesting cars from the $2011 GRM Challenge

Photos of the our car from the $2011 GRM Challenge