How much retard for how much gas?

[Steve-UK]

Hi

I was just wondering what different people did in this respect, I have always gone with 2 degrees retard for every 25 shot of gas as a rule of thumb, but with higher amounts of gas I do not knock it back that far. I use a MSD ignition unit so the retard only comes in when the gas is on.

So what do other people do?

[speedtweekerz]

2 degrees for 25 hp is very conservative. really you should be closer to 1.5 degrees for every 50hp. it also depends on the engine. 4 and 6 cylinders you can get away with up to a 50-75 hp with no reduction in timing. v8's up to 125 with no reduction. notice i say "up to" -- because it also depends on the strength of the internals in the engine and the output capabilities of the fuel system. these estimates are of course on a stock engine. hope this helps! you may want to review this link as well! http://speedtweekerz.com/NITROUS-101.html

[mrr23]

years ago, i asked NOS what their take was on it. they told me 1*per 50hp and the first 50hp didn't count. this is for a V8 motor.

[speedtweekerz]

exactly, i tell customers 1.5 degrees to keep them on the safe side of things until they can get properly tuned on a dyno.