Data from drag strip

[Bob Wooten]

Good evening gents,

I was @ the track the other day & was checking out the data tonight &
thought I would run a few things by Y'all.

we had a small discussion about Intake Air Temp a while back & I had noticed
that by the time I was @ the end of the 1/4 that the IAT was about 3 degrees
cooler (I have a super ram, cold air intake & a 383).  this I thought was
pretty cool & had not noticed it before.  This time I went I was running
slicks & I just noticed that even during the burn out (I was not doing a
burn out with the radials, no sense, they went up in smoke any way), that
the temp came down about 3/4 of a degree. I was doing about 45 to 55 second
burn outs.  I had thought that it was flying down the track that was
actually cooling the intake tract, thus reducing IAT's.  But it appears that
just pulling air in does it.  just an observation is all.

Second is that I noticed that the MAP was actually dropping as the motor
came up to about 5200 rpm.  I take it to about 5700 to 6000 for the shift
point & from 5200 to 5700 you can watch the MAP drop.  I could not figure
out what was "wrong".  makes me think, one of two things.  first is that the
383 has enough volume @ that RPM to start to draw a slight vacuum on the
plenum (although I don't think so, that is why Lingenfelter made it so darn
big) OR, that there might be a restriction upstream of the TB, that is
allowing the motor to draw a vacuum on the plenum.  I think that the later
is probably the case, cause of the Cold air tubes that I have.  I think that
the next time to the track I am going to take my clothes dryer duct & some
duct tape & do a couple of runs to experiment.  Also we had a discussion
about IAT's & taking cold air from the engine bay (K&N right on TB vs. cold
air package).  I forgot my TB K&N so I was not able to do that test.

thoughts?

Bob Wooten
r71chevy at earthlink.net
www.r71camaro.homestead.com

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org