The Dyno
We did these tests on a Superflow 901 dyno in 1995. The engines we
tested were instrumented for A/F ratio at all times. In addition, we
took some baseline measurements of compression and leak down to calibrate
the basic condition of the motors.
Test
Information
The data is provided in the form an Excel spreadsheet I used to record the
results. Most of it is self explanatory, but there is some personal
shorthand. I'll try to clear up the majority of them here.
The letters "S/A" or just "SA" stand for "Super America". This is the
gas station where we purchased fuel. We specifically used their 90
octane for much of the testing. This fuel had 10% ethanol. You
can see that we compared it to many other fuels and blends...particularly
Amoco 93 octane (which didn't contain any oxygenates).
Here's some more info -- you're going to find out anyway -- when the notes
say "+2 oz/gal"...this is referring to the amount of nitropropane added to
the fuel. Also, we tested several air filters that had been measured
for air flow. That's the CFM rating we gave them. Also, there is
something referred to as an "EGT" header. This is a header we added
individual exhaust gas temp thermocouple ports to. We tested it to see
if it made any performance difference compared to an unmodified header -- it
didn't -- so for many tests, we just left it on.
Some tests have mention of "double humps" and "turning vanes"....these were
little objects we inserted into the intake tube to see if messing with the
airflow in the intake tube made any difference.
One last thing. Typically we did 3
consecutive "pulls" with each different combination. At the bottom of
each set of 3 pulls, I averaged the data for all 3 pulls and provide those
figures in bold in each section. It's those bolded numbers I used to
assess what a change did.
Legality Disclaimer
When you look at the data, you will see that we tested a lot of stuff that
isn't legal. We did this to find out if LEGAL work in an area would
pay dividends. There is no point in working on something that doesn't
matter.
The Data
OK, here it is...the
Mumm Brothers Dyno Archive. This preceding
link should open up an Excel spreadsheet giving you all the data and should
provide hours of entertainment and probably some speed.
The bottom line: much of this will probably not be of tremendous help
to you...but just look at the results comparing a tight vs. a loose cam
belt. If nothing else, this data should point out the importance of
keeping on top of your maintenance. Another very valuable bit of info
contained in the data relates to your driving. The optimum shift
points vary by gear...and this data lets you calculate what those shift
points should be.
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