Q: I need some help getting my 1969 Camaro in the 12s at the track. The car has a 350 small block (bored .010-inch over) with 10:1 compression, .488/.510-inch lift hydraulic cam, ported Chevy “turbo” iron heads, Holley 750 cfm double pumper carburetor on an Edelbrock Performer RPM intake, Mallory Unilite distributor and coil (38 degrees total advance), and Hedman 1 5/8-inch primary headers dumping into 2 1/2-inch Flowmaster dual exhaust. The engine is hooked to a Turbo 350 transmission with a 3,500 rpm stall converter. The rear axle has 3.73 gears and a posi unit.
The suspension has been updated (traction bars, adjustable shocks, new rear leaf springs and shackles) so I don’t think the problem is there. I am using a set of street-type slicks.
My best quarter-mile run to date is 13.142 at 101 miles-per-hour with open headers and 104 octane fuel. My 60-foot time was a 1.907, and I shifted at 6,500 rpm. The car runs and drives great, and I’ve been told it should be running in the high 12s.
I’ve also been told to switch to 1.6-ratio rocker arms (I have 1.5-ratio rockers now), install a bigger cam, and use a 4.10 or 4.56 ratio rear axle gear. Any suggestions would be appreciated.
A: Your problem lies in your 60-foot times.
A 1.907 is closer to the time we’d expect from a car with radial tires, not with slicks. You say the suspension is OK, but we’d suggest giving it another look. For example, check your pinion angle—you want it to be around four degrees. To insure good weight transfer, set the front shocks to a 60/40 or 90/10 setting, and the rear shocks to 40/60. Also, check to see if your rear springs are stiff. To do this, push down on the car’s trunk lid. You should be able to push it down a couple of inches before the suspension starts to stiffen up. If the car doesn’t budge, you might want to consider a softer set of springs to help the car launch better off the line.
There are a couple other things you can do at the track that will help get where you want to go. Before you make a pass, do a really good burnout to get your tires nice and sticky. After each pass, pull a spark plug and take a reading (try to avoid idling the engine too much). We think you’ll find the carburetor is running too rich and needs to be rejetted. This will improve 60-foot times and throttle response, too.
We’d focus on these areas first before swapping out a bunch of parts.