10 % nitro

running in a 6.50 class with a 200 inch front motored dragster. 6-71 on a 477 chev 11.7/1 compresson 30 lbs of boost 20 amp msd pedal clutch 2-speed lenco.stuck at 6.70 can i add 10% to the mix to get me a little closer without hurting the titanium exhaust valves ?

 

you will need more than 10% to pick up .02 that amount will only get you a little smell. you need more like 20% before you begin seeing any (small) gains. once you go over 33% then you will make good gains but you will have to start adjusting (or upgrading) your fuel system. i am no authority with blown small percents but thats the way it works with na.
frank

 

The biggest reason people don't see much of a gain with small percentages is that they richen things up so much, it negates any of the gain...in fact sometimes they slow down! As far as the tuneup calculations are concerned, the tuneup for 33% nitro is the same as alcohol. Below 33% it actually needs to be leaner than alcohol. Above 33%, it needs to start getting richer. This is because the stoichiometric requirements don't increase as fast as the specific gravity as the percentage is increased (until 33%).

Of course, a smart racer wouldn't start out leaner until they've found where the timing and other things are happy (to keep away detonation). But the old rule of thumb "Richen it 5 steps for 20%" is complete bunk. Start a little richer than normal and sneak up on it.

Spud
www.fuelinjectionenterprises.com

 

You are already getting some good advice. In answer to your valve question, it will be fine. I have heard some numbers thrown around where you need to watch the ti-valves with Nitro, but it is nearer the 40% numbers. I don't even know if that is correct, but we have some experience in the area you are asking and have seen no ti-valve problems with our Chevy or the Hemi.

Rapid