standard to hi-helix

we run a 470 chevy 4.5 bore 6-71 standard rotor retro (rules)38 percent overdrivin 110 enderly 11.7 compression,brodix 2-extra heads 38 degrees timing 20 amp MSD.we are now bolting on a 6-71 hi-helix,retro case with Kobelco K-11 rotors.how much more fuel should I add to be safe?

 

we are making 22 lbs at 38 over . no one can seem to tell me how much more boost with the hi-helix deal. 2 lbs ? 5? 10?. how much difference have you guys seen going from a 14 to a 14 hi-helix someone out must have an idea. i can go way safe with fuel volume but i dont want to make 20 passes to get close again. thanks alot for your info

 

WHEN WE SWITCHED WE HAD NO DIFFERENCE IN BOOST AT END OF RUN!!! WHERE WE HAD THE DEFFERENCE IS ON THE HIT OFF THE LINE!! IF YOU RUN 1/8 MILE YOU MY SEE SOME.IF BOTH BLOWERS ARE THE SAME YOUR BOOST AT THE TRAPS SHOULD BE THE SAME,BUT YOU WILL SEE A DIFFERENCE IN YOUR 60 FT. BOOST. OURS WAS ALMOST 5LBS.IN FIRST 60FT.AND AT 40 OVER WE HAD 38LBS. ON BOTH AT END OF RUN..DON'T KNOW IF THAT HELPS YOU ANY???

 

You might want to consider richening #1 and 2 port nozzles by 10 percent to start, rather than burning it up. The new blower tends to provide a lot of quality air to the front of the motor for the first few runs.

 

Thanks for you help. we ran the car last sunday at thunder valley in south dakota. on the 4th pass we had the blower speed the sane as the old one , 39 0ver .020 smaller main jet, nozzels were not touched temps within 40 degrees. the car picked up 5 mph and made 4 more pounds of boost so far. I can see that if we spin it faster it will make more but I ran out of pulleys.our quickest pass yet at 6.731 @ 209.63