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electric supercharger debate ends here
- Subject: electric supercharger debate ends here
- From: mark kibort <mkibort@xxxxxxxxxxxxxx>
- Date: Wed, 11 Nov 1998 12:10:05 -0500
Message text written by INTERNET:bmw@domain.elided
>whole-house fan I installed in my attic is rated at 7000 cfm, and is
powered
by a 1/3 horsepower electric motor. There are a bunch of manufacturers ou=
t
there who make auxiliary electrically-driven radiator fans, which tend to=
be
rated anywhere from 600 - 1200 cfm, and most of which include a 20 or 30
amp
fuse in the kit. They simply aren't using a lot of power to flow a lot of=
air. Capiche? =
>>>>>>>>try and do this kind of air flow thru a 3 " pipe as I have done. =
=
not that easy. but your power assessements are valid.
Many of the items that Mr. Kiborti discusses make sense when collectively=
looked at, such as the very significant drop in cfm when pressure is rais=
ed
to the stated .35 psi over ambient, and the stated power gains at the
stipulated pressure, although they seem just a little bit high. (3% makes=
absolute sense when looked at through the SAE Standard J1349 lens, but 4%=
seems high.)
>>>>>>>>>>>>>>>>Thank you very much. It is sighty more than that if you=
take into account the 1 psi neg. (yes, 1 psi neg) that was measured in th=
e
air box with no mods, and then the positive .25 to .35 pressure measured=
after the fan was added and turned on.
after understanding what that might mean to HP , I deceided to dyno it an=
d
found that the measurements were right where I expected them to be 4 HP=
for the 4 banger and 9 hp for the V8. I think it was a success.
I personally would like to see *all* the details, but my understanding is=
as
follows:
Both engines showed a significant (over 3%) gain when tested on a Dynojet=
,
with back to back passes made with and without the device. That is to say=
,
each engine was tested with a completely stock intake, and then with the
device installed (or vice versa). Furthermore, this was a more or less
immediate process (same hour).
>>>>>>>>>>>>>>>>back to back tests withing 15 min of each other and 4 run=
s
done 2 of each . all showing the exact (within a hp ) all the way from
3000 to 6000 rpm. Ill fax or send you by email the dyno run from frey
racing if you want to see it. =
Max pressure gain was .35 psi, measured somewhere in the airbox, downstre=
am
from the device, with engine(s) at full throttle at max. rpm. (If this is=
true, Mr. Conforti's objection that airbox measurements are meaningless i=
s
unfounded.)
>>>>>>>>>>>>its true and I measure it many times . and tryed to reduce=
there restriction by opening things up too. there is some major sucking
going on down there , and even with the suto ram air that most people hav=
e,
even at 120mph, it doesnt reduce that air box vaccum. Go test your car f=
or
your self if you dont believe me.
Of course, the devil is in the details, such as airflow restriction (if t=
he
device was left in place without electrical power for the "before" runs),=
and heat dissipation (if the motor is in the airstream). There may very
well
be many practical problems, as well, such as packaging concerns and
cost/benefit. However, I don't see anything theoretical that makes Mr.
Kiborti's device the equivalent of the perpetual motion machine.<
>>>>>>>>>>Thank you again. but I can tell you the fan was not in the a=
ir
stream for the before runs. (very easy to remove and why would I want t=
o
do that. It would skew my findings. also, the motor is only drawi=
ng
400 watts , call it 80% efficient from the manufacuturer data. (high end =
,
rare earth motor) and 100 watts of heat sitting in 500 cfm of air flow,
well you can do the calculation, Im tired of doing them for Jim, but i
can tell you it maybe worth nothing in temp rise.
bottom line is that it works and give a 3-4% hp increase . on the dy=
no
and carefully tested and witnessed. Next , ill video tape the entire
event, and compress the video to MPEG so you can watch it . the 911 is
next. 4 dyno runs with and without the fan.
should be interesting.
Thank you again for the " reasonable , non argumentitive" comments
Mark Kibort
ERAM electric ram air system
Web page next week Innovations.com ( not on line yet)
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End of bmw-digest V9 #486
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