If you are a frequent reader of GM High-Tech Performance (which, you better be) you may remember this Camaro from our last issue. Terry and Helen Angell had a great time running 13.38's but, like all GM enthusiasts, stock just isn't going to cut it.
Their Camaro is a 2010 2SS, equipped with an L99 engine, a 6L80E transmission, and a set of the stock 20-inch rear wheels, which they would like to make a bit quicker and more fun to drive. With this in mind, we assembled a couple of longtime GM tuners, builders, and programmers and let them loose on this 2010. HP Tuners stepped up big, supplying us with a full 2010 Definition File, allowing a staggering amount of control over both the engine and transmission tables. Corvette Masters of Maitland, Florida, supplied us with a killer facility and its Dynojet chassis dyno, so we could have Jeremy Formato of FasterProms work his magic.
Admittedly, there were less than ideal conditions during dyno testing (in the heat of July), with ambient temperatures averaging 90 degrees and super-heated, 117-degree incoming air temps. However, these are very realistic conditions for the average summer across the country, so what you see here represents what most 2010 Camaros fitted with the L99 engine and 6L80E transmission will put to the tire, on an SAE-corrected Dynojet. In between each run, Jeremy and the crew from Corvette Masters allowed ample cool down, but not to the point of running the car too cold.
Check out the rest of the story to see exactly how much power we picked up. Numbers aside, Terry reports, "as far as the tune goes, it definitely has more balls down low and will spin heavily on the 1-2 shift, which gets a ton of attention. The other big part is the fact the car downshifts more aggressively, even with only part throttle, which makes the car much more fun to drive. I suspect now that the big issue will be getting traction."
As you can see, this engine...
As you can see, this engine bay is "as delivered" from GM. Jeremy did remove the factory painted engine cover in order to help keep heat soak to a minimum, as well as allow easy diagnostics, should anything happen while on the dyno.
Prior to tuning, it is important...
Prior to tuning, it is important to establish a solid baseline. After getting the Camaro up to temp, hooking up the wideband, and checking all of the dyno equipment, Jeremy put the hammer down and made our first pull.
Baseline numbers were: 317.53...
Baseline numbers were: 317.53 rwhp and 310.14 lb-ft of torque. While this may seem low (and below what an LS1 Camaro usually puts down) it is important to remember that this is through a 6L80E, an independent rearend, a set of 20-inch rear wheels, and 117-degree IATs. Considering this car ran a 13.38 at 105.5 mph, it is clearly a strong runner.
Taking a careful look at the...
Taking a careful look at the stock air/fuel ratio, we can see that the pull starts out somewhat lean and then tapers into the 11.7:1 range from 4,000 to 5,500 rpm, where it finally comes back and leans out to a desirable level. With some careful tweaking, Jeremy can optimize the fuel table to help make some more midrange power.
A closer look reveals an extremely...
A closer look reveals an extremely lazy torque curve below 4,000 rpm. This is something we could feel during both track testing and street driving. According to Jeremy, this is mostly due to the anemic stock timing and rich wide-open throttle fueling tables.
After looking over the dyno...
After looking over the dyno graphs, we moved into the stock computer and started to analyze the HP Tuner datalogs. These are key to making informed decisions, so spend a lot of time in here before you make any changes. You can see any number of factors, but Jeremy and I were most interested in the Advance (in degrees, total), the KR (knock retard), and the MAF/MAP numbers. You can see a slight hint of knock on the top end, something Jeremy will address as he tunes.