Looks like it's slipping. You might also get a shorter belt if your are tightening more than you expected.

 

That's actually an older picture with the S-trim and 3.12 regular pulley.

Now I have a slightly smaller pulley (2.95") that I bead blasted and had hard anodized. The surface is slightly rougher and more matte than even the Vortech Hi-Traction pullies.

I was thinking of fabbing up a tensioner that 'pinches' 2 idler wheels together right before and right after the blower pulley. A tighter pinch would also result in more wrap.

Thanks,

Jim

 

I ran a 2.85 with my YSi. Saw 18-21psi.

 

It looks like the blower pulley has plenty of wrap, I would be looking at that crank pulley some.

I never had any luck with the gatorbacks at all, I dont know where that all for started from, I tried a gatorback for 2 passes and it was off the car. Slipped like a ****. Best luck I had was with NAPA belts, they look like gates but they measure a little thinner. I was scared they would switch private labelers so I bought ten of them, whatever they are they work great. I spent a little time with several different belts, I hate slippage.

But you have too little wrap on that crank pulley IMO.

 

I ran Dayco belts.

 

Any rubber dust I see is always around the blower pulley area, but maybe to be sure I'll take the blower pulley off and do the bead blasting/hard anodizing treatment on it as well. I know that hard anodized surface is pretty tough.

There's a NAPA shop nearby that has Dayco. I'll try that too.

Thanks,

Jim

 

NAPA branded belts and dayco are different I think but either is probably better then the gatorback.

Just because the dust isnt there doesnt mean it isnt slipping, like someone else mentioned the long unsupported span, whipping and not a lot of contact on the crank pulley is what I see. Thats just te first thing that hits me when I see the picture.

 

Maybe a stupid question..


But why does the belt dissappear off to an idler way over on the right side of the pic ?

Is it actually doing anything ? Why not just run the belt straight to the blower ?Ive never used a Gatorback, but my current Gates belt hasnt missed a beat for several months now.

Gates ???

 

I thought the same thing but he already answered

If you could just go right to the crank and get the tensioner over enough where it almost touches the belt on the other side when tight that would work a lot better I would think.

 

So you need a stronger/better tensioner bracket ??.

That simple tube does look like it could be improved for strength.


Or....

given there are only 2/3 pulleys ( if going straight to blower ).... can you get some 10 or 12 rib ones made ? Assuming you can get suitable belt lengths.

 

I originally designed the setup to clear an engine-driven radiator fan. I couldn't go straight down then because it would hit the fan hub.

Also, I first had this set up for a Powerdyne, then modified the mount plates to lower the blower and accept the Vortech S-trim, then I went to e-fans. A classic case of creeping elegance along with learning new things.

Now that I know more about supercharging, and have seen some of the ultra-rigid, thick plate setups out there, my design is due for a complete makeover. I still have a few Bandaids to throw at this one while I work out the details.

Bandaids:

Change the top mount point of the blower tensioner so that it orients correctly to the forces it will see if the belt goes straight down to the crank pulley.

Reinforce the tensioner with a couple wedge-shaped wings that extend down from the tube and triangulate the tensioner mount tube.

Redesign:

Redo the 2 mount plates in 1/2" or 5/8" steel.

Machine the front plate so the 3 large lower Vortech bolt mounts have a solid steel backing, for rigidity.

Add 2 steel spacers to the front peanut-shaped reinforcement so that it bolts solidly to the front mount plate.

For the blower belt, fab up a tensioner with gear teeth on one side, and make a 3/8" square-drive round gear that I can put a breaker bar in to tension it before tightening.

Instead of spacer tubes between the 2 plates, make some rectangular spacers with boreholes in them so I can orient them to help triangulate the 2 mount plates.

Redo the tensioner mounts so the shafts are thicker and stronger and are correctly oriented.

Luckily I have access to a full machine shop and have some CNC skills, so I can make pretty much anything I need. Also the Metal Supermarket is right up the street and I can pay the cutoff fees in beer...

Finally, plate or coat everything for corrosion resistance.


This is great. I've always known there is a lot of knowledge and experience on this site, and I appreciate all the suggestions.

Thanks,

Jim

 

If you are building things I would do a jackscrew style tensioner, way easier to deal with cranking it down then a gear tooth arangement that needs two hands. At least you have a lot of room to work with.

 

Good advice, thanks.

Jim