Percentage of nitro

Running a blown BBC on alch 12:1 comp ratio,what percentage of nitro can one add to the tank before its found to be a bad idea? Also if I am running 33 degrees of timing,adding nitro what timing changes would be needed?Dave

 

You will need to add timing depending on the nitro load. Give spud miller a call www.fuelinjectionenterprises.com

 

You could run 15-20 % without having many changes, you will need to fatten it up a bit.
If and when you do, close off, or turn around any High speeds etc,.till you are comfotable with what the plugs are telling you.
Example say you normally run 110 main you might wind up starting with a 90-95 with the Low percentage of nitro (10 to 20 %) and a flat or two on the barrel valve,..you shouldnt need to change the timing untill you are up over 40-60% but at 12-1 that wont work so well.

Like mentioned you could talk to spud and have your system flowed to know exactly where the starting point of this game begins.

 

Some good reading at www.onehotchilipepper.com (see the nitro notes) and http://www.turbofast.com.au (see the racing fuels section).

 

get ahold of a guy named dale wilkins he goes buy lurch on here he has been running a nitro fuel alterd for years a very good at it also ricky ruze he goes buy the california rattler he runs also very well..Dave

 

15-20 %

I don't know because this is one thing we haven't tried but ,,, I have been told by guys that have run 15-20 % in nitro coup that it is easier to run 65% because at 15-20 % it is not stable and will sometimes burn the engine up for no reason. is there any truth to that?? or just not having the right tune up.

 

At 15 to 30 % its still a Alcohol tuned engine with a added steroid (nitro), If they had issues thats because they probly didnt stay ahead of keeping it richer than normal or tried to run to close of them being an actual nitro tune up. Yes the more nitro in the tank after 60% is better tunable because now you are actually getting to tune for nitro instead of alky, 15-20 % is casual, you will get the smell, a little pop, and yes a slight performace or wake up of the motor.
The nitro coupes were only allowed up to 50% per nhra rules, was this the ADRL nitro coupes,..running at 50 % you can and will be chassing your tail for the most part because you are trying to tune with two different fuels that require two different volumes, GPM, nozzle areas etc,...What you have is still doable,.just do it with control of understanding that the more you up the percentage the more you will have to change your combo to meet the percentage level of greed and wanting more more more of it.

 

Craig Moss good call on Spuds web site,answered all my questions.He really lays it all out for pretty much any percentage of nitro you would want to run.Thanks ITA,Dave