hotairgypsy

Two days ago i went to the track and was not running my best times but put down a 12.8 and a 12.9. after running those times i ran into a problem. my MSD launch master started acting up on the line. It governed out and I had to limp down the track backfiring and proceeded to run my best time(being obnoxious) of 56 sec. I had to turn up the limit on it to like 7000 so i drive the card normal. With all the spuddering and backfiring i kept thinking in the back of my mind if i flooded the plugs or anything. The car seemed to run fine overall.

So tonight i go and run and put down some sad times. Keep in mind i had a passenger with me for the first time. He is the neighbors son, 16 years old, probably weighs 160ish at a guess. I ran 3 times with him in the car and only changed the tire pressure on the MT streets

run 1

33 lbs of tire pressure

reaction .790
60ft 1.86
mph 99.29
et 13.398

25 lbs of tire pressure

reaction 1.017
60ft 1.928
mph 98.33
et 13.586

15 lbs of tire pressure

reaction .66
60ft 1.916
mph 97.86
et 13.646

i know the humidity was at 53% here and it is at 4300 ft of altitude. Temp was at about 75 degrees

how the heck do i go slower with lower tire pressure? My best run ever in this car without a passenger was a 12.515. How much did the passenger slow me down?

Hufenstang

if i remember correctly 150 lbs is equivalent to 2 tenths

tungsten07

i've always heard as far as weight reduction goes 100lbs.=1/10

acascianelli

Altitude?

Wouldn't that 13.39 adjusted to sea level be more like 12.7? When you ran your personal best were you at the same altitude?

hotairgypsy

yes...i ran at the same track...that was like 6 weeks ago. but i know it was before we got in the rainy season...i would guess the humidity then was like 12% unlike last night at 53%. i do not know how big a factor that plays

Simon1

Did you figure out why your MSD was acting up? How is it switched?

hotairgypsy

i have the msd triggered by the line lock switch....i am guessing it is acting up due to me having it set real low...i had it at like 1500 ...i am still learning all this so i could be totally wrong on how i have it set

hotairgypsy

anyone know how humidity effects HP?

Simon1

It sucks it away.

Back to the MSD. You don't have it wired to the clutch with a reed switch? Seemed like the easiest thing to do.

Simon1

There are places on the Web you can go to figure out your DA. It will ask for temp, humidity and altitude.