I was curious about retard. My car has a 408 SBC with 14-1 compression, Brodix track one heads, Brodix intake with 1050 Dominator carb and a.639/.629 lift cam installed on a 105 degree centerline I also have an MSD-6AL with a multi step retard. Normally with a 200hp shot of N20 I take six degrees of timing out, but I have had a couple of friends tell me to take ten degrees out. My plugs look fine with only six taken out. Will it really help taking the extra four out and should I take it all out at once or six on the first step and four on the second? The car has run a best of 9.99@131 with only six being taken out and hitting my rev limiter at 1000 foot mark. Any help would be greatly appreciated.

Thanks, MIKIE

MIKIE,

Listen to your friends. They are giving you some good advice! Rule of Thumb is 2 degrees of retard per 50 hp added with N20. So 200 hp = 8 degrees retard. One thing I will tell you is don’t run your engine against the limiter too often or you will get some nasty results! When your engine stutters while injecting nitrous it can and will hammer your pistons and rings. Look for the correct gear ratio to get you thru the traps off the limiter. Once you have correct gearing some testing with retard will give you more info on a "happy" motor and better performance.

Thanks for a great question!