RTD2 is a fat slob

[ultimatesurfa]

Hey guys i went to the track last nite and found that i still have a fat F'n slob for a truck Heres the scenario 2 weeks ago the truck ran 14.8's and 9's with only 91 mph...then i took off the 24 lbrs and it went 14.3@95 mph...So i gave RTD2 a diet and it worked...But i am still Fat....I have 2 50 lb auxillary injectors that was calibrated to feed a stock manifold that had a super long runnerThis runner would start on one side of the engine and long curve to center dump .....that with the 50 lb aux's i experienced puddling etc but basicall got very descent performance considering the stocker(manifold) isnt desinged to flow fuel..I have found that with the shorter runner M1 single plane manifold (that i have now)and its direct shot at the valve and 50 lb auxillaries are now flowin too much...I took 1 50 lbr off today and put a 24 lbr in its place to run with the other 50 lbr for a total of 74 lbs of injector dumpin under boost ...i will try it tommorrow as a startin point...I'll just ease into boost and see if it'll sustain it..(before i relied on 100 lbs of injectors to deliver and additional 160 or so ponies(@rear wheel)Now it looks like thats wasteful with what i have now..lookin for combo(want my blower to sing again

I was wonderin if any of ya tunin gurus had any ideas...Fuel pressure differin wont matter here...I have already tried it and the truck still ran fat..i went from 49 psi down to a dangerous 41 psi(static).RTD2 ran the same 14.3 sometin...so that wont work...Guess i am fishin for a combo..I have seen a RC engineering(for injectors) and i can get any thing i want soooooo that'll be my parts source...Any help or ideas appreciated...Cause the only other answere is to take off M1 and go back with stocker and back to where i was(13.7's) but want the M1 to work.......Yu can understand my tuners muleheadedness......

surfinnnnnnn(sorry for long post)

 

[FMOS Racing]

I think you're on the right track. Honestly, I think two 24lb injectors may be enough. I don't have time right now, but later (if no one beats me too it), I'll work out the power/air mass/fuel mass stuff and let you know what you need for 160 hp.

 

[ultimatesurfa]

Jeff your help would be a killer..Today i did some full boost runs sustaining for 15 secs or soo..It pulled harder and the whining is more prevalent,,,So success today Du bugger feels better..74 lbs is a step in the right direction..I now can play around,,I have been told that the paxton for the dodge has 36 lb aux's(72 total)..I am at 74 down from 100...movin in the right direction..I would love the help with what ya brew up..thanks Bro!!!!!surfinnnnnnnnnnnnnnnnnn

 

[FMOS Racing]

Ok, here's the formula -

Injector Flow = (HP * Brake Specific Fuel Consumption)/(# of injectors * duty cycle)

What I don't know for your application is the duty cycle - I'm not sure exactly how your setup fires the injectors. We'll use .75 as a starting point - this means the injectors are open 75% of the time. We'll also use .6 as the brake specific fuel consumption constant for your supercharged motor.

Injector Flow = (160 * .6)/(2 * .75) = 96/1.5 = 64 lb/hr theoretical ideal at 75% duty cycle.

So, if you can find out the duty cycle of the injectors (how much time they're open before they close and then reopen) from whoever makes the auxiliary driver setup, we can fine-tune the details on that.

Later!
Jeff

 

[ultimatesurfa]

Thankx braddah,,,Jeff from what i understand my injectors are ran @ 75 to 80 % duty cycle due to temporary nature that they are used(only under boost)With that scenario looks like my 74 lbs(actually 75 cause 49 psi on 24 lb injector is just like a 25 lbr) is in the vicinity..RTD2 feels alot better.... I really aprreciate the help....

I have seen those tables and formulas on msd's website and didnt try to apply em....Too much surfin Time to wake up..Thankx Braddah any more info is gathered and noted and will be applied...This tunin gets fun...