MM54

Figure this one out - the air pump has been removed, and I had the single alternator belt and a single tiny belt between the main pulley and the waterpump. There was a chirp between 3-4k, so over the winter I got the Banzai dual sheave alternator pulley and Gates belts. Put them on, set the tension, took it around the block a couple weeks ago. No issues (with the belts). Jump forward to today, the first nice day we've had this year. I re-tension the belts since they were loose-ish from having been run a little bit, and now it squeals like a stuck pig over 5k RPM. Should I back the tension back off? It is to spec (half an inch of deflection with however much pressure the service manual says) but it didn't make noise when they were a bit looser.

I've never seen a belt make less noise when it's loose! Seems backwards.

DivinDriver

iTrader: (15)

Belts may have hardened some from weather and lack of flexing, or you may have a little surface rust on the pulleys.

You could try a little belt dressing spray to make the belts adhere better and soften them up a bit.

tommyeflight89

iTrader: (4)

I got the same kit from Banzai.

My setup has some belt squeal also. Strange that you have more squeal with less tension.. can't explain that. The ambient temp also plays a role, only when it is warm outside does the clutch fan kick in more and load up the pulley. On cool spring/summer mornings I would never get squeal.

I think that the Gates belts shipped with the kits are slightly larger than what the pulleys require, in terms of width, noted by the longer dashed line on top:

\------/
\-----/

I notice with my belts that after slipping many times they are wearing in and seating better in the pulleys, but I still feel that belt tension must be set too high to avoid slipping. I am going to try different belts.

Banzai has very good customer support, they may chime in.

I have been frustrated with the belt setup for a while, another option I am looking at is the Atkins Multi-v pulley kit:

Atkins Designed Rx7 Serpentine Pulley Kit

Banzai-Racing

iTrader: (11)

First verify that the alternator is installed correctly, I have seen far too many where the alternator bolt spacer was installed on the front side of the water pump housing. This obviously causes the belts to be out of alignment. If you are saying the belts make more noise with more tension, then reduce the tension and see if it diminishes, easy enough test.

All belts stretch a little as they break in. It is difficult to set the deflection correctly with a pry bar, which is why we developed the adjustable tension alternator bracket. Pulleys & Belts (86-91 RX-7)

t_g_farrell

iTrader: (1)

So I see Banzia chimed in but I have to ask, did you call them about this first? Kind of rude to start a thread calling them out like this if not.

MM54

I don't mean this to be a "call out" to Banzai - I don't think it's a problem with their kit at all! I just mentioned what I used to provide detail if anyone had seen this before - sorry if it's been interpreted the wrong way. I appreciate the feedback - this morning I loosened them a hair and the squeal comes on a little earlier, so I may tighten them up a little more and see if it moves the other way. It seems to do it more when hot (i.e. the fan clutch is engaged and they slip on the waterpump pulley) which makes sense - it was a cold day the time they didn't make noise so it could have been a fluke. I also noticed one of the belts sits a hair deeper into the pulley than the other, making it a little looser. Not sure if it's a belt length, width, or pulley groove difference. I may swap the belts front/rear and see if it follows.

I did see the precision-adjuster when I ordered the pulley kit, but I've not had issue adjusting v-belts before. I may have to spring for it if this doesn't clear up, though!