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Nitro Question.....

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mphmotorsports:
Going to run 30% Nitro later in the year..... Once I fine tune my Hilborn Injection Stack set up (Changing from 16as to 14as nozzles and setting up High Speed Bypass), do I need to put more fuel to the motor when I put 30% Nitro mix in ( with 14 as nozzles, I'm planning to start out with a 75 main jet) and what about the timing (currntly running 38 degrees) and what about the high speed???
Thanks for the help!!!!! 

hotrod316:
we when 33% last year and changed nothing = 2ths FASTER.
 thanks to the man 8) grandpa Coker he may have saved our little motor ???
be careful using  the 2 step, dropping cyc at the start.
our first pass is on here somewhere or u tube sm racing first pass on nitro
IT'S A BLAST
MAN SUMMER COME ON i NEED A FIX
ASK MY DRIVE AMANDA ABOUT BURNING THE PAINT ON THE CAR WITH THE GOOD STUFF ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???

mphmotorsports:
Was thinking about the 2-step also Hotrod 316.... 8) might have to lower the launch rpm a little to... will look for your first pass and Thanks for the info....

JrFuel Hayden:
I assume your change to the smaller 14 nozzles is for running alky. I would think running 30% you would need more fuel/ bigger nozzles.
I would call Don Enriquez at Hilborn, he can be a big help on what you are trying to do. Also Spud can help.

Our all iron SBC NHRA Heritage Jr Fueler, burning only alky, running raised runner 23° iron heads currently using 14 nozzles, with a 1/2 Hilborn pump.  The main jet I run is mostly .76, and a .90 jet in the high speed, running 120 to 126 lb of fuel pressure, 2.36 to 2.40 fuel flow, depending on weather conditions, at 29-31° of MSD mag timing. Now I know non-raised runner 23° heads run more timing, like 36-38°.  BTW we, Hammer-Hansen-Hook, won the 2013 March Meet running that tune-up, running 7.02-7.04 @ 187-188 mph.
It looks like you are running alum heads and the timing may be different than iron heads. Just take a good look at the plugs looking for signs of detenation. Black or white speckles on the plugs, if you see that, back down on the timing or add more fuel pressure, or both.

To further confuse you, when I raced my 98% nitro high gear real Jr Fuel car in the mid to late 60's I ran 55° of timing with another 20° of advance in the Vertex, and a 110 Enderle pump [ a Top Fuel pump, at that time] . Our tune-up at that time was far-out, but I did run 192 mph in 1963, with an all iron 301 SBC , on 9" M&H's. Car weighted 980 lbs, no driver.

Good luck with your project.
Jon Hansen, Hayden Wheels, 800-624-3803

hotrod316:
I went to FUELINJECTIONENT.COM site and use his tune up section helped a lot,
we also drop down the rpm by 400 on are last pass at 33%  :-\ no time slip
but the recorder said it should have help
it does make it smell GOOOOOOOOOOOOOOOD
p.s.I think spud wrote about this for us, see if i can found it
   

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