I was looking into the supercharger thing for our hemi's and came across this "electric supercharger". I thought if they could generate enough CFM, it might work. It would be a lot cheaper, is available now, but wouldn't deliver the HP that a belt driven one would. I decided to e-mail them to see what they had to say. Here is their response, for what it is worth.
Thank you for your interest in the e-RAM Electric Supercharger.
Due to your engine's larger displacement (over 5.0L), you will need two
e-RAM's mounted in parallel (one on each side of a "Y" intake tube), then
entering the single tube which then enters the throttle-body.
Now for the long answer:
The e-RAM normally provides roughly 5% HP boost for any engine up to 5.0L or
engines with a baseline hp of 300hp or less. Due to your engine
displacement, as your rpms reach closer to 5000 rpm, the HP gain realized by
the e-RAM will diminish (this is due to the lessening differential between
your engine's CFM requirement and the e-RAM's CFM flow). Also, there will be
slightly less HP generated by the e-RAM at lower RPMs as well (1000-2000
rpm). As the engine rpms increase, the engine develops a greater demand for
air (pressure differential between inside the engine cylinders and the
outside atmospheric pressure), then the resulting vacuum in the intake
system increases. Some of the gains from the e-RAM come from offsetting
this vacuum, which will be lower at low rpms on a bigger engine.
So if you were to use a single e-RAM unit, most of your engine's hp gains
will be between 2000 rpm and 4000 rpm. With the single e-RAM setup, we
would anticipate a gradual reduction in boost from 4000 rpm upward to
red-line. Your engine will have a max CFM requirement of around 550 cfm
at 6000 rpm, and the latest generation e-RAM can flow close to 1000 cfm, so
although hp gains will decrease as rpms go higher, there will be no hp loss
through the highest-end of your rpms. Long story short.... with the single
e-RAM, you may end up with 4% gains, mostly at the mid-range (2K to 4K) of
your RPM's from the e-RAM (instead of 5% gains through the entire RPM range
like on smaller engines).
This is what we saw during tests on our Porsche 928 S4 race car with the
5.4L engine pushing 400 flywheel hp (now configured with two e-RAMs mounted
in parallel feeding single intake).
The only way to get the full 5-6% HP gain from the e-RAM through the entire
RPM range on your size engine, will be to mount two e-RAM's in parallel (two
separate intake tubes with an e-RAM attached, then merged as a single intake
to the throttle-body), as that will double the potential flow rate to 2000
cfm, and assure the 1 psi delivery to your intake (we did this for the Dodge
Viper 8L V10, and got 25hp gain on the 450hp base with two parallel mounted
e-RAMs..one on each 5 cylinder, 4L side of the engine). We don't yet have
dyno results for your specific engine.
We know of one customer with a 5.7L Hemi that mounted two e-RAMs in parallel
to pressurize his stock air-box (made a custom mounting configuration), and
seemed to think that it was worth it. But again, we do not have any dyno
Hope this helps -
e-Racing Motorsports, LLC.