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Help with Eaton M45 Supercharger bracket
Chaz - 18/10/13 at 09:18 PM

I have a few problems when faced with making a supercharger mounting bracket.

1. Do I need to install a tensioner for the belt?

2. Without an auto tensioner can I just use a pivot on the mounting bracket?

3. How much bhp/torque will the supercharger need?

4. How strong does the mounting bracket need to be?

Lots of questions, hope you can help me!

Thanks in advance

mark chandler - 18/10/13 at 09:26 PM

My M90 has a sprung tensioner and is very firmly fixed, it will use quite a few HP to drive it, maybe 30bhp at full chat so mountings must be strong.

The belt also needs to wrap around the pulley so you will need an idler to make sure it connects to at least 60% of the circumference.

Regards Mark

MakeEverything - 19/10/13 at 01:37 AM

quote:
Originally posted by Chaz
I have a few problems when faced with making a supercharger mounting bracket.

1. Do I need to install a tensioner for the belt?

2. Without an auto tensioner can I just use a pivot on the mounting bracket?

3. How much bhp/torque will the supercharger need?

4. How strong does the mounting bracket need to be?

Lots of questions, hope you can help me!

Thanks in advance


1. Yes

2. No, as it takes the pulley out of line and the belt will jump the pulley or wear on the outside edge

3. ?? What is it youre asking? The engine will drive the pulley and the gains greater than the losses (if planned right)

4. Very. Some of the torque from the crank is transferred through the belt to the S/C, and vice versa on decelleration, so think of a twisting motion. It needs to be strong. I used waterjet cut brackets that started at 15mm thick and that seemed fine.

If youre asking these questions now, you need to do some more planning / calculations. I found the book; Forced Induction and Tuning, by Graham A Bell a great help. There are others ive read as well, but this will get you started.

pewe - 19/10/13 at 08:48 AM

If you go onto MX5nutz there's a whole section on forced induction.
As above brackets need to be substantial - IIRC mine are 8-10mm plate if not thicker.
Some installations use a single tensioner something like a VW Passat cam belt one should do.
There are specific blower belt tensioners from Moss Europe and Jackson Racing (JRC) though not cheap.
BTW s/c alignment vertically and horizontally is CRITICAL otherwise you'll chew belts and/or run the s/c nose bearings - ask me how I know!
HTH.
Cheers, Pewe10

johnH20 - 31/10/13 at 06:21 PM

Another excellent source of info is 'Supercharged' by Corky Bell ISBN 0-8376-0168-1. Tells you how to calculate everything you need to know about belt drives, power requirements etc.