Big block Chevy Camaro MS3-Pro

[KeithBoden]

For a number of years I was running a supercharged big block chevy (540 ci) with an old Holley Commander 950. The intake manifold is a converted single plane carb manifold with a home made throttle body assembly and the rest of the setup consisted of GM sensors, a 7-pin HEI distributor, low impedance injectors run from a AEM driver and a single WBO2. I wanted to step up to a sequential ECU for control over individual cylinders, dual WBO2s, EGTs and more so I bought a MS3-Pro.

With the 12-rib supercharger pulley, hanging a crank wheel and sensor out to the front would have been difficult so I addressed the crank position with a 36-1 wheel mounted to the back of the damper.

IMG_20160713_012349 - Damper mounted crank wheel.jpg

For cam positions sensing, I thought about adapting a later model (Gen 5+ BBC) timing cover and timing set that has provisions for a cam sensor but would have also had to modify the Mark IV style oil pan to properly mate to the newer timing cover. The cam gear I had already had 3 windows/3 'spokes', so I mounted the same late-model cam sensor in my existing timing cover and set up as a polled cam sensor.

IMG_20160717_195512 (2) - Engine position sensors.jpg

I kept my AEM injector driver and wired up the MS3-Pro to my existing electronics panel inside the car. I pull the engine out of the car more often than most, so I kept with my previous practice of wiring everything through a circular bulkhead connector. (Tip: always run a few extra/unused wires through the connector so you can make changes later without having to solder/unsolder from the big connector. Since I was going to run the CAN bus through the connector as well for EGT and possibly future analog inputs, I only ran 3 extras wires for PWM or other outputs.

IMG_20160705_031325 - Panel wiring.jpg

(To be continued)

[KeithBoden]

On the ignition side, I went with aftermarket LS2 coils mounted to aluminum brackets welded to the valve covers. At first I tried mounting them close enough to use factory length LS plug wires but with the larger dimensions of the valve covers and heads of the old big block, I ended up picking a better aesthetic location and made custom wires.

IMG_20160712_013432 - Coil mounting.jpg

I used Spartan Wide Band controllers for the two WB sensors and built a simple box for interfacing a pair of EGT probes to the CAN bus using an Arduino and a few breakout boards. I also included a 3-axis accelerometer and with the extra analog/digital inputs/outputs on the Arduino, I could easily a few extra sensors or controls in the future.

IMG_20160717_195512 - Thermocouple CAN interface.jpg

The finished install looks pretty good in my opinion, and by testing all the wiring as I went along and following the manual's suggestions for setting up the tune, the engine started and idled on the first try!

IMG_20161028_091119 - Engine in car.jpg

Video of the first startup:
https://www.youtube.com/watch?v=9zj5JKCBJK8

[KeithBoden]

I have gone on to add a flex fuel sensor and am working through the tuning process in the naturally aspirated mode before I bolt the Procharger F1-R back on. Between TunerStudio and the capabilities of the MS3, I think I am already ahead of where I was after years of tuning the Holley Commander 950, which to be fair, was a much older system that was still good enough for 50,000+ miles on the highway and 1000+ miles on road courses. If anyone has questions about the particular settings, sensors, or wiring I put together, I'm more than happy to answer!

[KeithBoden]

I got a question about the crank wheel set up on the back of the balancer. I had a few constraints when it came time to do a crank trigger:

• Don't mess with the pulley locations or I will have to shim the supercharger out from the cylinder head and I already had to go from 3 pulley bolts to 6 because of the load on the pulley
• Put the wheel somewhere that makes sense for the crank sensor and bracket
• Don't interfere with the timing pointer because I like it and will need it (even if only once to set the timing offsets) This meant making a wheel that was the same size as the balancer or smaller, 7.250"
• Keep the wheel teeth away from the balancer so it doesn't interfere with the sensor

There was about a half an inch between the back of the damper and the front lip of the oil pan. I sketched up a profile of a trigger wheel with a step to keep the teeth away from the balancer back. I debated on attaching the material to the damper and then cutting the teeth or cutting the teeth first and then attaching it. I chose the later and also added a step to the profile of the wheel so it was the tiniest bit of a press fit into the ID of the balancer.

Crank Timing Wheel.JPG

I found a piece of 1/2" cold rolled plate, cut a ring out of it using my mill, turned the profile into the ring with the lathe and drilled/milled the teeth with the mill. (Yes...I bought an indexing head a long time ago, rarely used it and then used it to hold the part while CNC'ing the holes and teeth )

IMG_20160704_144645 - Crank wheel.jpg

I lined up the teeth so that the 1st tooth would be 40 deg BTDC, pressed the wheel lightly in to the ID of the back of the damper and then TIG welded tiny tacks between the wheel and balancer. If it wouldn't have been a Fluidampr, I likely would have drilled and tapped the balancer to mount the wheel. (Tack weld at 11 o'clock in the picture)

IMG_20160713_012407 - Wheel mounting.jpg

I went overkill with the .220" wide teeth, however, the timing turned out almost perfect and I haven't had any trouble with the crank signal yet. I did have to bump my #1 tooth BTDC to 41 degrees to get MS to match my timing pointer, not bad though! If I didn't have the constraint of the timing pointer, I would have bought a pre-cut wheel, spaced it out from the back of the balancer with some shims and welded it on. I also really wanted to make a strange tooth wheel, like 47-3 just for fun but also didn't want to make the wheel again...

[suberimakuri]

Way to go mate.