Date: Fri, 5 Apr 1996 16:21:42 -0800
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: wabbott@mtest.teradyne.com (William Abbott)
Subject: Smog check, II, wieght.
Little Martha, my '70 Single Cab, is finally legal! I got the
smog check, official wieght and verification of VIN done today and
DMV gave me new plates and stickers. I've got insurance, I'm On The Road!
I'm also getting about 17mpg :( This for the first tank- just over 200 miles
for just over 12 gallons of Chevron 92 Super Unleaded. I hope it improves
as the engine loosens up.
Gotta stop trying to stay with 65mph+ traffic too. 60mph would
probably help.
Smog Check results:
'70 single cab:
1600 sp, 34 PICT, 200 miles on engine.
Timing 5 degrees AFTER tdc.
2500 RPM
Measured Allowed
HC(ppm) 26 (the form printed out had no specs for
CO% 0.17 2500 rpm measurements. Note that what I've
CO2% 15.2 got would pass the Corrado's 1993 spec!
02% 5.4 Are there any high-rpm specs for old cars?)
RPM 2604
First try at idle:
HC(ppm) 351 700 PASSED 50%
C0% 7.39 6.0 FAILED 123% Too Rich!
C02% 10.1
02% 6.8
RPM 1029
After a free leaning-out adjustment by Mr. Chahal:
Second try at Idle
HC(ppm) 195 700 PASSED 28%
C0% 4.82 6.0 PASSED 80% Mo Bettah.
C02% 11.9
02% 11.0
RPM 1051
Both idle measurements were hard to make: the 'exhaust dilution'
alarm kept going off, indicating that the exhaust gas flow was allowing
burbles of outside air to get up the tailpipe to the sensor input. Mr. Chahal
stuffed a rag part-way up the tailpile to block this back-flow. I'm using
the single $39.00 BugPack muffler with my extractor pipes.
I also went to the official wieght station and can tell you
that my single cab wieghted in at 2600 lb, with 1/4 tank of gas and
no passengers. There was a pair of old sheets of plywood in the back,
as a bed-liner.
Here's a comparison of the bus versus my Corrado:
'70 SINGLE CAB '93 CORRADO
1600 sp 34PICT 2800 VR6 FI
2500 RPM 2500 RPM
Measured Allowed Measured Allowed
HC(ppm) 26 ? 12 220 5% of spec!
CO% 0.17 ? 0.06 1.2 5% of spec!
CO2% 15.2 15.1
02% 5.4 0.3
RPM 2604 2410
Idle
pass/fail
HC(ppm) 195/351 700 12 100
C0% 4.82/7.39 6.0 0.00 1.0
C02% 11.9/10.1 15.1
02% 11.0/6.8 0.3
RPM 1051/1029 702
Timing 5 degrees after TDC 6 degrees before tdc.
Wow, the quality of combustion in the Corrado is MUCH better- mostly
due to the catalyst I'll bet. The lean-out adjustment resulted in much more
O2 in the bus exhaust, while also slightly raising C02, AND lower unburned
hydrocarbons.
So how come the sum of C02 and O2 and C0 are different percentages
for the Bus and Corrado??
I like how the Corrado HC, CO2 and O2 numbers are the same at both
RPMS. It passed w/o adjustment. This is after 3 years and 56,000 miles. I
also like how good the combustion at 2500 rpm is in the bus.
I'd say power-robbing smog equipment works pretty well... :)
23 years of engineering progress in action... It makes me
want to try bolting a catalyst on the extractor before the muffler.
Cheers,
Bill