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Old 05-23-2020, 08:52 PM   #98 (permalink)
mwebb
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Join Date: Jul 2009
Location: New York
Posts: 510

no nickname , it's just a car - '04 volkswagen golf tdi
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this is a fun thread

i use a very long hill on a highway and hit the top at 60mph
record max speed about 50% down the hill at an exit ramp where it levels off and at a road marker near the bottom
using a GPS
primitive but shows improvements or UNimprovements when changing tires or various things to reduce drag
in nuetral or in gear just keep the testing conditions the same

also engine load
showed a straight pipe , electrical conduit , 1"od decreased load by a huge amount at constant speed over the same stretch at the same temp , in a geo metro
years back
so yes larger exhaust diameter is NOT always better
and
max load at WOT also improved 7 or 8% if i remember ..... graphed with AutoEnginuity
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