About a month ago I bought a second-hand K&N Fuel Injection Performance Kit
(FIPK) from a group member, Brian Tully. Thanks to Brian, it was in
excellent condition and delivered quickly and exactly as promised!
Anyway, I made a plan to test exactly how much if any improvement was made
from the FIPK utilizing the Horsepower mode of the trusty G-tech. The kit
was installed on my '99 Dakota 4wd w/5.2l V8. I ran three series of test
runs, first with the TB spacer, second w/o the TB spacer (completely
stock), third w/o the TB spacer but w/the K&N. I will spare the details of
the testing unless anyone cares, however I made every attempt to keep it as
scientific as possible.
The truck had an AIRAID POWERAID throttle body spacer installed by the
previous owner that I also wished to test the value of. Given that the
increased height of TB spacer prevents it from fitting under the hood with
the K&N intake ducting (or AirRaid for that matter), it had to come off
anyway. I was informed that the PCM needs at least 5 miles to make its
adaptations, however I think it actually takes more judging from the
results I got while preparing to run the actual tests. As such, the 1st
test with the PowerAid should be completely accurate, however further
"adaptation time" may have shown better results for the non PowerAid and
the w/K&N runs.
BTW - the weight of my entirely stock truck with a Leer 100R camper shell,
full tank of fuel, and small toolbox was exactly 4800#.
Here's the numbers:
1. Stock truck with PowerAid Throttle body spacer. Ambient air temp -
73F, average HP from four runs = 173.25 RWHP
2. Completely stock truck (w/o PowerAid). ambient air temp - 78F,
average HP = 174.25 RWHP
3. Stock truck w/K&N FIPK (w/o Poweraid). Ambient air temp - 70F,
Average HP = 182.75 RWHP
Estimated horsepower gain from PowerAid TB spacer = -1 HP
Estimated horsepower gain from K&N FIPK = 8.5 HP
Estimated mileage gain from K&N & removal of TB spacer = approx. 1-2 MPG
Again, I expect that a test now that the PCM has completely adapted to the
new intake would show higher numbers.
Opinions:
The "Helix Bore" that AirAid described in their TB spacer is simply an acme
thread machined into the bores, which I cannot see creating anything but
turbulence within the intake tract. Additionally, given the twists and
turns of the stock intake manifold, I'd be surprised if any of that
supposed "spiraling" air made it to the first bend in the manifold, let
alone past the injectors and into the cylinder. When I first researched
the Intake systems and TB spacers last year, AirAid gave sample dyno #'s
and some specific #'s on their web-site, but conveniently did not list
specifics for the Magnum engines. I wrote to them several times and was
finally told that they "could not release" the exact #'s for the Magnum
engines, however the writer could assure me that it would make substantial
improvements in mid-range horsepower, torque, and mileage. I will say that
the spacer is very nicely CNC'd and anodized and it makes a beautiful
paperweight. If anyone would like pictures I'd be happy to oblige.
The K&N FIPK made a very noticeable change to the performance AND sound of
the vehicle - both with the sound of rushing air under the hood and a
change in the exhaust note. The throttle response is much improved as is
the seat-of-the-pants increase in performance. That freeway on-ramp is
much quicker with more exciting sounds than I expected. Given these
results, I will admit to driving the truck harder than normal during the
first week, but it was so much fun. The mileage even with my heavy foot
improved by 1.2 mpg, and closer to 1.8mpg on the second tank - however this
was only around-town driving...to and from work. I can-not say exactly how
much it will change the highway mileage. Given the contortions of the
stock air-box, intake tube, ribbed flexible duct-work, etc. it's a surprise
that the OEM setup worked as well as it did. BONUS - The K&N greatly
improves access to the engine and specifically the right side spark plugs.
I hope this information is of use, please feel free to ask any questions.
Kevin
Kevin Sellstrom, W6KTB E-Mail:ksellstr@softcom.net
***Wilton, California***
'99 Dodge Dakota CC, 4x4, 5.2,
'69 Dodge D200, 4x2, 318,
Also: '83 Volvo 244Ti, '85 Volvo 244, '68 Volvo 122S, '98 Specialized
Rockhopper A1FS
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