SCCA Camaro

Since missing the February SCCA Solo II event left me a few weeks on my hands, I decided to tackle the wide-band air fuel ratio sensor install, and Holley Commander 950 ECU to support it.  I had picked up the Commander 950 as a used unit off of eBay a while back and was waiting to get my whole package together to install it.  I had also purchased off of eBay a Holley wide-band O2 sensor that was compatible with the Commander 950.  It had a control box and the more desirable NTK WBO2 sensor.  I also wanted an A/F ratio meter on the dash, and was in luck when I saw that Holley sold one that plugged right into the WBO2 control box.  These weren’t showing up on eBay, so I sourced one from www.carshopinc.com where they were about $20 less than Jeggs and Summit, and even more importantly they didn’t gouge me with a handling fee and shipped via USPS, which is always cheaper to Hawaii than either UPS or Fed-Ex two day (which is three days anyway).  Tom at Car Shop Inc was helpful and hooked me up with the meter and the gaskets I needed for the Holley Stealth Ram that go between the plenum and the intake runners.

I downloaded the instructions from www.holley.com.  What you need is document 199R-10149-7 for the Commander 950 install, and 199R10265 for the Holley Stealth Ram install.  Additionally you’ll want the base maps.  I printed all of these and put them in one place for easy reference.  Another good resource is the EFI message boards over at www.chevytalk.org.  It seems to be where the C950 users congregate and there are several knowledgeable people there that are very helpful.  I started by dropping the exhaust pipe from the collector on the passenger side header and drilling a hole in the header for an O2 sensor bung I had also purchased off eBay.  The C950 manual has on page 92 instructions for placement and angle of the O2 sensor in the exhaust system.  The hole should be at a slight angle up above the horizontal to keep condensation off the sensor.  Also if you have the wide band O2, which is heated, it can be placed in the exhaust system after the header collector, which is where I put mine.  Because the narrow band O2 sensor is not a heated sensor it needs to be in hot exhaust gases when making its measurement and then it’s recommended to place it closer to the exhaust valves.  I welded the bung in place with the exhaust still hung on the car and upside down with the front of the car on jack stands, so it was pretty ugly—but it got the job done.  Although Holley calls for a two inch hole in the firewall for the wiring harness, I found I could get everything through with an inch and a quarter hole if I squared the hole off a little bit with a file.  Of course I picked up a grommet from my local hardware store for passing all of the wires through the firewall since my eBay-sourced used Holley Stealth Ram and Commander 950 didn’t come with the grommet.  After the welds cooled I placed the NTK sensor and ran the wire up through the firewall and into the interior of the Camaro. 

The Detroit Speed and Engineering front coilover suspension conversion was much stiffer and more predicable than the suspension on my 4th generation Camaro, but I decided to stiffen the shock setting up a bit to minimize the body roll I had seen in the photographs of the 1968 Camaro during the autocrossing events.  I also wanted to lower it just a bit, in order for the car to have a little better stance (it had the appearance of being lower in the rear than in the front) and to lower the center of gravity of the car for improved handling.  Unfortunately, unlike some of the other coilover conversions available in the aftermarket, the Detroit Speed and Engineering design requires you to break your lower ball joint and swing the lower control arm out of the way in order to remove the coilover to adjust ride height or the shock setting.  While this can be done in a few hours with the correct tools (maybe even faster if you do it all the time), it’s a hell of a lot more work than just turning a dial or set screw to adjust your shocks and turning a spanner to adjust your ride height. 

But I’m starting to get the hang of adjusting the coilovers, having done it a few times now from setting the car up to going through the RECON inspection to fixing a problem with the Delrin spacers used on the coilovers between the spring and the aluminum spring hub.  After a few height adjustments, my spacers from Detroit Speed and Engineering were toast, all cracked up.  Unfortunately a few calls to DSE netted only confusion, so I decided to machine my own, on the CNC milling machine.  I made them out of Delrin, but a little thicker than the ones DSE sends with their coilovers, so they would be less prone to cracking up.  Later I called back and got Stacy Tucker on the phone—she sent me new Delrin spacers from DSE for free, which I accepted not yet knowing how well mine would work.  I also made my own spanner wrench out of an old aluminum bicycle crank on the milling machine, because I went to 4 different places here on Oahu and no-one would sell me one, and I didn’t want to pay $50 to ship a $15 tool to my residence here in Hawaii.  It took one long morning to adjust the coilovers to one click off the stiffest setting (to match the rear shocks) and drop the front end ride height by four tenths of an inch.  My homemade spanner worked pretty well.  My coilover spacers worked great, so I saved the one from DSE.  A few test rides around town confirmed this setting just barely scrapes the headers on the highest speed bumps, so it’s either right on or just a wee bit too low.  It fixed the stance too, so now the car appears to have a neutral to slightly leaning forward stance.  Someday I’ll get some headers like Doug’s tri-y’s with more ground clearance, but for now I was satisfied with the adjustment.

The next race was February 17^th—so it was time to start planning for any improvements or upgrades to be made.  The Camaro had a nagging exhaust leak as well as a power steering pump leak that I planned to address in the month before the next race.  Since I was taking the headers off the car, I decided to strip the rust off of them and coat them with high temperature POR-20 (cast iron color) while I was at it.  The POR-20 is made by the same folks that bring us POR-15, which I used on the floor pan of the Camaro earlier in the blog.  POR-20 is for high heat applications, up to 1400 degrees F.  After removing the headers, I spent hours scouring them with a Scotch-Brite pad and the metal prep products from my PPG paint system, DX579 Metal Cleaner followed by DX520 Metal Conditioner.  After a thorough dry in the warm Hawaii sun, I put two coats each on the headers with a disposable brush.  I found the easiest way to do this was to hang them with a wire from a header bolt hole, which allowed for good coverage on the headers without too much in the way of acrobatics and/or messing up areas I had just painted.  The headers look 100% better than they did before I coated them, so it was time well spent. 

Hot starts, which were a problem because I had increased initial timing to 14 degrees because I had such a big cam and wanted more torque off the line, seemed to improve with the POR-20 treatment on the headers, which was a big bonus from doing the coating.  I had the Camaro ready for its third autocross outing.  Unfortunately though, I was travelling on the road for work three of the four weeks in February, and came down with something that I never could kick…and was sick for the event day of the 17^th.  I thought it most prudent to stay home and recuperate, so started planning for the next event date…March 30^th.  After my travels and recuperation from my illness, I had about a month to do some additional improvements to the car, and decided to tackle the front end ride height and shock setting on the Konis.  If I got that done, I figured I would install the computer for the Holley Commander 950 along with the Wide Band Air Fuel Ratio controller and sensor.