Hey guys, I'll admit I do not have a Bonneville, however I thought you guys of all people will know the answer to this.

Is this a M62 or M90?
I don't know what year of Bonneville this SC came out of.
On the bottom it says Rev R or A?

Also, I'd like to know as much as I can about this design of Eaton SC.
I'll be the first to admit, i know absolutely nothing about this SC.
If anyone could please just point out what each port is for and etc. That would be a massive massive help and would be greatly appreciated.

Pictures:







Thanks a lot guys!

M62!

The M62 supercharger was manufactured by Eaton, exclusively for the GM 3800 engine. HP was rated at 205 for 1991-1993 engines (models vary), and 225 for 1994-1995 engines.

The M62 is a roots style blower Roots type supercharger - Wikipedia, the free encyclopedia

The large triangle hole is the blower discharge to the intake manifold. the two round holes are intended to minimize the SC whine and are often referred to as 'silencers'.

Picture two is the by-pass valve. this decreases SC pressure when backing off the throttle, and putting the car in reverse. It keeps things from going kaboom!

Picture three is where the throttle body is attached.

Hope this helps.

Fantastic sir, you were of great help!

May i just ask you one thing, how were you able to identify it as a M62?

Picture 4 is the BCS, Boost control solenoid.

The shape of the case and the short snout.

This is a M90

Can anyone explain exactly how the BCS works? Thanks again guys!

The BCS is the device that opens and closes the boost by pass valve. Also..the snout is longer on the M90, but the silencer holes are different also. The M90 silencers are slits, where the M62 are holes. See Dan'* photo below. Notice the slits in the SC lower compared to the holes in the photo of your M62.

I do have all the pictures Kevin.

I went a looking and figured you'd post one up. I changed my post to include a lookey loo at this photo and compared to the M62.

Thanks buddy!

Ah, I see. What about this area here in red, what is this purpose of this if the outlined blue area is what provides the air?

Once again, I can't thank you enough for the wealth of information!



Also, I'm going to take a stab and say the BCS works off of vacuum correct? Vacuum at idle/lower revs is higher holding the valve open, but at higher revs vacuum decreases, allowing the valve to close. Correct?