Got a race-car only TNT tomorrow in Denver, and I'm wondering how to use my passes to identify helpful changes to pick up time. I have a 1 inch spacer to try under the carb, and can remove the 2 1/2 cherry bombs on my 2 inch headers to see if there is a restriction. I havent' installed the 3 inch flowmaster pipes with Ultra Flow mufflers. I May have gone too big on the header primary size, a common mistake as bigger always seems better, for a current low 13 second ride, and may still change to 1 3/4 before being commited to the exhaust system install. The math says I have 337 RWHP with 4,150 lb race weight which is probably not enough power for 2" primaries. The shift point for now has only been 5500 RPM.
I can also change mechanical advance springs in the MSD distributer with 6AL, change timing, jet size, spark plug gap, shift points, footbrake RPM, etc. I just don't know whats a good place to begin for a newly completed vehicle. The old rule is make one change at a time, but the sequence is probably important too. The plugs do look like a darker tan, so not worried about being too lean.
The vehicle is a '70 El Camino with 496 iron heads, Victor Junior, Holley HP 750 carb, 3000-3500 stall TCI Ultimate Street Fighter, Turbo 400/ Gear Vendors (not shifted on the track)3.73 12 Bolt, 325/50 MT street radials. Ignition is 6AL, 8361 MSD vacuum advance distributer with Blaster 2. I'm installing the distributer/coil tomorrow and removing the HEI and am leaning toward the 18 degree bushing and 20 degrees initial. Its generally accepted that the altitude requires 4 degrees more timing here than at sea level. Cam is Comp Cams flat hydaulic with .575 lift and 240/246 degrees duration and 110 LSA.
I'm not impressed with the low 13's for the dollars of redoing the entire drivetrain, but I'm down about 20% on power at almost 6,000 ft elevation. But I have picked up six seconds over the old 267 V8 in the car passed off to me as a 305, and with a 2:41 final cog.
I remember the old lady in the timeshack laughing when she handed me a timeslip at 19.4 seconds - I almost quit racing. How do I go about doing the testing to start having a little more fun? I've gone from 19 seconds to 13 seconds, but still want to get out of the "teens" with this ride. I could run in King Street at 12.75's.
I can also change mechanical advance springs in the MSD distributer with 6AL, change timing, jet size, spark plug gap, shift points, footbrake RPM, etc. I just don't know whats a good place to begin for a newly completed vehicle. The old rule is make one change at a time, but the sequence is probably important too. The plugs do look like a darker tan, so not worried about being too lean.
The vehicle is a '70 El Camino with 496 iron heads, Victor Junior, Holley HP 750 carb, 3000-3500 stall TCI Ultimate Street Fighter, Turbo 400/ Gear Vendors (not shifted on the track)3.73 12 Bolt, 325/50 MT street radials. Ignition is 6AL, 8361 MSD vacuum advance distributer with Blaster 2. I'm installing the distributer/coil tomorrow and removing the HEI and am leaning toward the 18 degree bushing and 20 degrees initial. Its generally accepted that the altitude requires 4 degrees more timing here than at sea level. Cam is Comp Cams flat hydaulic with .575 lift and 240/246 degrees duration and 110 LSA.
I'm not impressed with the low 13's for the dollars of redoing the entire drivetrain, but I'm down about 20% on power at almost 6,000 ft elevation. But I have picked up six seconds over the old 267 V8 in the car passed off to me as a 305, and with a 2:41 final cog.
I remember the old lady in the timeshack laughing when she handed me a timeslip at 19.4 seconds - I almost quit racing. How do I go about doing the testing to start having a little more fun? I've gone from 19 seconds to 13 seconds, but still want to get out of the "teens" with this ride. I could run in King Street at 12.75's.
