dirt track racer 81

iTrader: (45)

Reading the plugs.. Porcelain was dark gray.. There is more fine tuning with pressure adjust than changing jets.

n2oguy5

How dark was it? Seems if the entire porcelain was dark grey, a jet change may have been needed. What does it look like now? Seems like that would require more than 'fine tuning'

How do you know what is too dark? Did you change timing at all?

brandon6.0

iTrader: (26)

Dirt track racer knows what he is doing. Like the very first post by phantom. A perfect tune up is a clean white plug barely any fuel ring.

He is also running a low pressure setup. Just pulling out 1psi fuel pressure makes a pretty big diffeence in the jetting. Like with mine being high pressure it takes more like 5-10psi difference to get close or be exact.

Every nitrous setup is a lil different.

skeet

iTrader: (18)

correct thus the reason i run a low pressure system now, its easier to fine tune the fuel PSI than swapping jets, not so easy with a high pressure system.

MPFD

iTrader: (5)

Was that 1.5 psi on a 5 psi set up or on a 10 psi set up?

dirt track racer 81

iTrader: (45)

On a 5psi set up.

TXsilverado

iTrader: (19)

you're on a NOS crosshair, or crossbar right? i'm planning the same plate someday (if i ever finish my truck). i hear the NOS jet charts are pretty far off. how far from the fuel jet/psi did you guys deviate for the final tune?

dirt track racer 81

iTrader: (45)

Yea it's a crossbar. I don't know off hand what jets Danny stuck on the fuel side..

Phantom

iTrader: (16)

Please don't pull 1.5 psi from 5 right off the bat and think you'll be ok. I suggest sending your stuff to Monty smith or induction solutions to have your setup flowed so you know what the tuneup should be