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quick nitrous vs. timing question

9 August 2002
Folsom, CA
hey all, i'm heading out to the dragstrip today to give my new zex setup a try. i have been doing some reading of some older threads and i gathered that retarding the timing may not be necessary until you are going with larger shots. i'm running a dry system that currently has the 55hp jet installed. zex says no timing adjustments are required. if i opt to put in the 75hp jet, zex recommends 4degrees retard. per an old thread in '02, they say timing "should" be fine at stock ... but i am only running 91 octane here in california.

fwiw, i do have the colder ngk's gapped at .035".

RedlineRex, the colder plugs are fine for the 75 shot and you do not need to pull any timing out,leave it as is.
what you should be concerned with is a bottle warmer for Stability and a full bottle.after no more then two runs pull the plugs and mark them per bank and number cylinder and examine with a loop.they should look very clean from the n20 run but what you are looking for is micro specs of metal flake,if you find this THEN PULL OUT TWO DEGREES AND REPEAT IF YOU CAN TOP OFF THE TANK.this is why a second tank is a must as is the bottle warmer.BTW before your runs insure that not only coolant but oil temp is up and if you make a second run wait for the warmer to bring the bottle up to spec(cook it off to 1000-1050 psi if you can as it will make a big difference in your returns.just my o2
best regards dave
dave, excellent tips (as always). i have a topped off bottle and i only plan on making a couple passes tonite. i'll inspect the plugs afterwards to make sure everything looks good. unfortunately i will not have time to wire up the bottle warmer before i head out to the track right after work. i'll take a look at the bottle pressure right before my run ... probably won't get up to the optimum pressure you recommended tho. thanks again for the info!! --paul
just got back from the dragstrip a few mins ago... having issues with the setup (user error, the zex kit work fine). first pass was a 12.84 @ 112.6...
the trap speed looks okay but the ET is pathetic.
second run, nitrous was on for 1st and 2nd gear the didnt turn on again.

for reference, i ran the car all motor three weeks back and ran a 13.05 @ 105. i'll post when i figure out what is wrong and hopefully have some promising results.