I own an asphalt Mod that will run at a 1/3 rd of mile flat track. The engine used is a 358 Chevy with Bowtie heads,roller cam,dual plane intake with a 500 cfm 2 barrel Holley.Also no gear rule. Is there any advantage in using a Tri-Y header over a four into one?
bob had the best answer
Did you Dyno both engines with the two different exhausts headers, to see which set gives you the best Torque Curve. Running a 1/3 mile flat track you'll want the most Torque at lower RPM. Then when you get back in the gas it will pull hard. Flames that come from the exhaust just tells me that with that header you maybe running lean. Flame from the exhaust is just raw fuel, and then when you get back on the gas the exhaust is hot enough to ignite the raw or un-burnt fuel laying in the exhaust header. My experience says go with the TRI-Y for a short track, and read your plugs after a few hot practice laps.Ignition Timing will also affect fuel consumption. If your running short races close your spark plug gap up .025 to .028. Even with a strong aftermarket ignition. Stay with the TRI-Y's and by shorting or lengthening your exhaust extensions you can move the torque curve around also.... Good LuckBob
Bob,thank you.The Tri-Y header combo is what I will use.