forcd ind

iTrader: (7)

as i am getting more fam. with using my laptop(that was a challenge) i feel i am getting closer on a tuneup, just the map thing is throwing me off
my engine wants a lot of timing off idle, my guess is because of the edelbrock single plane intake-i had to put a pretty aggres. pump cam in just to get a clean off idle rev, then cure the last stumble with the higher timing
with the procharger, i know i will dump some timing, also can use the retard for that, but seems i could use the timing graph to back down the timing for higher rpms(to many choices, lol)
i would like to see some graphs if possible, to give me some ideas of what you are using

Project GatTagO

iTrader: (7)

You need to back down the timing based on the manifold pressure. The timing retard switch is for nitrous so when the nitrous is activated it pulls a set number of degrees out. You really don't have that many choices if you want to do it right.

Andrew

forcd ind

iTrader: (7)

with the engine running, and looking at the 3 dials on the laptop, is the one on the far right (map) the psi that it is seeing? it seems to be lower than what i read with a vacume gauge

NO CATZZ

iTrader: (10)

Yes, that is the vacuum gauge. And mine does the same thing. I read about 8 on the MSD and 15 on my mechanical. The only benifit I have is that mine is track only so I don't use the vacuum advance.

jay_lt4

iTrader: (4)

the msd measures vacuum in "absolute psi" ,, with the msd around 14 psi is = to 0 vacuum on your vacuum gauge,, above 14psi is boost , less than 14 is vacuum

do some reading on absolute psi and it will all be clear as to how the vacuum system actually works

forcd ind

iTrader: (7)

while eating a Mcdonalds burger, it might have come to me, lol
they keep talking about manifold pres., but it really is vacume-manifold pres is present when the motor is off, or in a non vac state, like wot-the pres is the ever present atmospheric 14.something-so the map starts off with 14, subtract the engine vac, and that would be your manifold pres? in a blown state, wot (loss of vac) would be 14 + the boost amount?(needing a 2 or 3 bar sensor)
so in order to set my map timing, i could read the dial with the engine running, which is the pres its seeing, and relate that to the map graph-i think i got confused with the psi on the graph, thinking it was vac
am i thinking right now, sure makes my head hurt

jay_lt4

iTrader: (4)

correct it is confusing at first,, around 14psi is = to 0 vacuum or atmospheric pressure, anything above 14 psi is considered boost, below 14 psi is considered vacuum, lower psi = higher vacuum

so 15 psi is the same thing as 1 pound of boost on your boost gauge