Took the car out for its first real tuning run yesterday.
For those that know the area we went out on hwy 91 to 32nd ave, out to 276th
St. on the backroads, then the # 1 hwy to Chilliwack. Back on the #1 to 160th
st, and 88th ave home.
Got a "Those aren't the stock tailights." and "Why does it say Datsun on the
valvecover?" when we were filling up in Chilliwack.........
No top. Yes it was F**&$!%g COLD!!! Kind of funny driving aroung without a
top, going by farmers fields where the ponds are frozen solid!But nothing a
hot drink with the right anti-freeze couldn't fix. ;-)
The car is running very well. Pulls hard (for an 1800) up to 5700 rpm where it
was starting to lean out some. The tuning still needs lots of tweaking as it
goes very lean on throttle tip in, and the air/fuel ratios go as low as 10:1
and as high as 18:1 at different points while driving. For the most part tho
the afr was in the 13 to 15:1 areas when it mattered.
The "Autotune" feature in megasquirt seemed to be working very well as the car
seemed to be driving smoother all the time with it on. We did a lot of full
throttle runs to try to cover as much of the tuning map as we could.
Unfortunately, because it was a nice sunny day, it was kind of hard to see the
computer screen and I missed the "low battery" warning, and lost all the
settings when the computer shut down before I 'burnt' them to the ecu.
AARGH!!! Note to self: on a tuning run "Burn to ECU" every 15 minutes!!!!!
Oh well, It was a great drive in the roadster. Put on over 100 miles and used
about 1/2 tank of gas. Definately needs to be leaned out it a lot of places,
but feels really good. Nice idle at about 800-850 rpm. Would like to bring
this down to about 700-750.
Seems all the other things are working well also. GM alternator keeps the
voltage at about 14.2, the Hella headlamps work really well, and the dash
gauges seem to agree with the computer as far as rpm and temperature.
The 2" exhaust system is quieter than I thought it would be, but am actually
quite pleased that it is. The induction noise from under the hood seems louder
under full throttle. It is actually quieter than the old 1 3/4" exhaust. I was
able to pick up some 2" stainless pipe at the metal recyclers quite cheap
($40) and used that for all the straight sections. The muffler shop only had
to install/bend the piece that goes over the axle (regular pipe), and tighten
everything up. maybe one day a welded stainless 'over the axle' piece will be
available from a vendor..........
My cold idle valve, which is just an on-off air bypass valve, seems to be a
bit small. It only makes a difference of about 50 rpm when it is on so that
will need to be changed as well. I think it should have a cold idle between
1000-1200 rpm.
Woke up to snow again today..........I may have to wait for spring to get any
decent tuning time in. Lots of time to study the manuals I
guess..................
Merry Christmas to all!!
Daryl Smith
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