I have a JRSC m45 on my 95 Miata with AC and power steering. I want to remove the AC system to lighten the car. (90% of the time Miata is used for track days) I want to replace the AC with a dummy pulley. Is there such a thing? Thanks! Rod

 

I'm not following why you think you need a "dummy pulley." Just remove the system and get a shorter belt.

 

A friend had a 99 but his did not have AC. He cracked the head, 2x. I thought routing of the belt around the AC pulley would take some of the stress away? Maybe not?

 

Power steering pump should go away if you are doing even 50% track days. I ditched the power steering and kept the A/C.

If you think it puts different stress on the brackets to have the A/C pulling on the belt in addition to the PS you are wrong. And the PS mounts to the block and not the head anyway. I just removed the bracket. Your buddy must have been overtightening the crap out of the belt tension. It just needs to be tight enough to not slip under a little bit of drag. The A/C drags more than the PS so it can be less tight without the A/C anyway.

EDIT: For the PS removal I used a shorter belt and used a pair of washers between the compressor and the bracket to adjust tension. It was no big deal.

 

Ok I'm not looking at my miata at the moment but I could swear the power steering bracket bolts to the block and not the head. Sounds like serious user error if he cracked the head twice and blamed it on belt tension.

 

I think the head he is referring to is the blower head, not the cylinder head. I could see you cracking that if you went all angry monkey on the belt tension. IIRC the MP45s are really not supported all that well...

 

i have two m45 supercharger dummy pulleys for A/C and P/S... PM me.