OnyxCobra

If you are even gonna try to mess with an Eaton that wasnt supposed to go on your car in the first place you might as well get an M112. However they run hotter and use more engine power to run than Kenne Bells, I dont think an Eaton would be worth it.

FoxGT

You have to be careful when picking what car to get the supercharger off of. Some M90's had alot of intake accessories built into it like pcv, vacuum tree, ect... You want to try to avoid these if possible. There can be major fitting problems, they weigh alot more, and they are quite a bit harder to port. The one to look for has 4 bolts on bottom bolting it on and 2 bolts in the rear for the intake. Also, if you find a bad one don't worry too much about it unless it's been literally beaten to death. These are the easiest and cheapest things in the world to rebuild, you just want to make sure the rotors are in decent shape (very hard to mess them up)
The M112 isn't required for a stock or decently modified 5.0. It was built for a dohc 4.6, they can turn quite a bit more rpm so they need alot more air. If you look at how much cfm the two engines flow you'll see why they had to use the m112.
Same concept as the Probe GT's 2.5L v6 engine flows almost the same ammount of air as the 3.8L v6.
On the upside the M112 would run cooler than the M90 because it wouldn't need to turn as fast to get the same psi as the M90, but would also use more power to crank it even though at a slower speed. Better on the s/c worse on the engine.
There's nothing wrong with the eatons, people failing to maintain their vehicles is the reason they got a bad name. Factory ones didn't come with a very good coupler either, but there are plenty of aftermarket ones that are alot better than those and they are easy to replace.
For the bad name you have to take a minute to think about how many factory cars came with any other brand supercharger other than eaton, or any other types of superchargers for that matter. I don't know one type of car that came out with a kb factory, or a centri supercharger. If they start producing them, expect some bad news to come from all of them due to poor maintenance.
As for efficiency in stock form they get around 58% ae. Ported they get around 70% ae with a good port job, thats around what most centrifugal superchargers and turbo's get. If you need a company's word for it, email paul at injen tech. They did a test with the centri supercharger vs. turbo vs. ported eaton at the same psi. The eaton put down the most power of the three.
The news about it shocked me shocked me when I found out about it.


Here is the email:
We got the
supercharger from Thomas Knight already ported. It is true that roots type
superchargers have poor top end power delivery but it really depends on
which size charger you use. We also Extrude Honed the intake manifold and
did some of our own extensive porting, welding and reshaping of the intake
manifold plenum and runners to increase the chargers efficiency. We also
designed a custom intake that flowed exactly what we needed for this
application which also helped out in intake charge efficiency to maximize
air flow without over flowing the supercharger. We did the same for the
exhaust system. We built a few exhaust system set-ups and the one that
worked the best on the dyno was the one we have on the car right now. We
did all the tuning in-house on our dyno so we had al the time in the world
to do so.



Paul Ho
Research & Development
Injen Technology Co. Ltd.,
WWW.INJEN.COM
244 Pioneer Place
Pomona, CA. 91768
(909) 594-8393 Phone Ext. 12
(909) 839-0427 Fax
Sent: Wednesday, September 07, 2005 8:50 PM
Subject: Ported roots.

Paul,

To my understanding you've tested a roots supercharger against a centri.
supercharger and roots s/c And you produced the most hp at 7psi with a
ported roots type supercharger against a 7psi centrifugal setup and
7psi turbo setup. From what i've read the roots type supercharger has horrible
horrible efficiency at high end. Did porting it help that?

Thanks,
Isaac