It looks fine idling and isn’t trying to come off.

I just drove the truck on an hour trip out and another back and the belt stayed on but no WOT. I’ll try and get outside tomorrow with a ruler and see if I can tell if the pulleys are straight.

 

Ok, so it was hard to compare all of the pulleys with only a 12” ruler but as best I can tell, the generator pulley is lined up with the power steering and the supercharger might be slightly back, but the generator pulley is thicker. The adjustable idler pulley is slightly off compared to the stationary one. I can’t compare the tensioner to anything due to where it is.

 

I had the same problem, water pump pulley alignment was off and I needed the HD tensioner. Just go ahead and get the 8 the rib version as you can run it with a 6 rib belt.

 

I didn’t think the water pump would make much difference since it’s a smooth pulley. I replaced the water pump with a new OEM pump less than a year ago. I’ll order the HD tensioner but it won’t help me with our trip. It really sucks I’m going to have to worry the whole time about the belt coming off or partially coming off and getting destroyed. And keep my foot out of it…

 

I’m gonna chime in here again. I do not think you have an alignment issue here. I do think the HD tensioner will be helpful. Your statement “ i recently installed a magnuson supercharger” is my basis for all of my suggestions and conclusions. There is a learning curve on having a blower and the way you accelerate and decelerate. I have thrown tons of belts and broke several tensioners all due to being too aggressive. The problem is not going into boost aggressively but more so getting in it aggressively and letting out suddenly. I personally believe you will benefit from the HD tensioner as many others have in the past. Including myself.

 

What’s the point then if I can’t even pass one car without worrying if the belt is going to come off? If you have to let off, you have to let off. I have a supercharger on my SS and had one on a previous car and never had a belt issue like this. I’ll get the HD tensioner, but I thinks at ridiculous. I shouldn’t have to carry tools around in the car to put the belt back on at any given random time. My wife is not physically capable of putting a belt back on the side of the road with the kids in the back. That is insane and if that’s the case and they need to make that clear before you buy.

 

We have are a bunch of us that have been thru this, once you get it dialed in you will forget about it. I went 40k plus on one gates belt. How tight are you making the belt? I have mine tight as ****, zero deflection.

 

I’m currently on a Gates HD belt two sizes smaller than the belt that came with the kit (the ATI balancer is a tad smaller than the OEM balancer) and I pushed that idler pulley down as much as I could with the tensioner locked with the pin. Two one hour trips today and the belt did not move but I gave it zero WOT’s and only one or two maybe 3/4 throttle.

 

once you get into pulley changes and balancer changes then you have to expect hiccups. I have also pulleyed down several sizes and changed my balancer. Once you get into pulley changes this zone it becomes experimental and it’s trial and error or reach out on this site to people that hopefully have a similar setup. I have learned a lot and shared a lot here. It takes a little work but once you get it dialed in you will be fine. I always hoped someone would invent a second tensioner that would pick up the slack under full boost. I think that would fix a lot of issues.

 

I haven’t changed the supercharger pulley and I only changed the balancer to the ATI because I was told the stock balancer was causing this problem.