mysunset

iTrader: (2)

Since I am new to the whole FI game, I decided to take some advice of other memebers and replace the Gatorback belt that comes with the Vortech and replace with a Gates equivalent. The gatorback that comes with the kit apparently is slipping and not allowing the blower to produce full boost. Only making 6.6 max on average.

Got the new belt on, started it up and discovered the belt walked off the first rib of the idler pulley. So with that said, I have a couple questions:

Is the belt too tight causing it to walk off the rib?
Is there an alignment problem that would cause this? (possible suspect)

Interesting enough the stock gatorback belt does not walk over the rib. But considering the gatorback is slightly thinner belt, it may be more forgiving.

Phaneom

I'd start it up and check if anything is loose, like maybe one of the pullies on the plate.

teh215

iTrader: (8)

My guesss is that one of the pullies is out of alignment.

Phaneom

Yeah I was kind of trying to say what teh215 said lol, Maybe I got to much sun today.

kopo

iTrader: (4)

Mysunset, Who did your vortech install in chicago?

mysunset

iTrader: (2)

I did it myself... with some help of course. I am a detailed person and took my time. Fortunately my uncle owns a collision shop. I would not have considered performing the install without using a lift or having the right tools.

gspot35

When you tighten your belt, if too loose you'll see it flapping at idle. If too tight you will be able to look down your mounting plate and actually see it warped/bent. With an 8lb pulley you should not have to warp your plate to get a quite belt. Also make sure of your tension on your cog pulley, you need to be able to spin the cog idler. Too tight and it will affect your serp belt and be loud! Neither brand belt should walk off!

kopo

iTrader: (4)

Did you get the 93 or 93.5 in belt?

jpc350z

Which one is the cog idler?

gspot35

Look at the pic, it's the one with the arrow. You should be able to spin this by hand. (when the engine is off, j/k)

mysunset

iTrader: (2)

I bought the 060930 belt initially and was not able to get in on. too tight with the stock pulley. I purchased the 060935 = 94" belt and am using that.

mysunset

iTrader: (2)

thanks for the toughts. when I loosen up the cog pulley, the cog belt flaps and sounds horrible. So I have it tight enough so that it will not flap.

as for the serp, I do not see that it may be warped when I look down the belt at idle. looks square to the mounting plate.

Just a thought, while installing my mounting plate, I read that it would help align the pulleys better if you place the washers on the inside of the mounting plate towards the engine. Do you think, the additonal space of the washer would cause the belt to be slightly off and make it walk off?

jpc350z

I believe the 935 represents 93.5in.. Which is the same size as mine. Works great.

kopo

iTrader: (4)

ok thanks, going to buy the gates 935 belt right now

gspot35

I second the 93.5" belt. Also remember to trq your serp. idler pulley to 23ft.lbs of torque.

mysunset

iTrader: (2)

what is the risk of having it tighter than 23ft lbs? trying to pin point my belt walking issue.

gspot35

At first, I kept playing with belt tensions to get squealing to stop. At one point I just followed the belt tightening instructions to a tee. I noticed a torque spec on the idler, and simply torqued it. Squealing stopped. I guess the tighter the idler is, the more tension?

Nothing to do with the belt walking I can think of!

mysunset

iTrader: (2)

So let me ask this... what would prohibit making full boost? In a previous post of mine, someone mentioned that the belt needs to be tight. So i tightened it down.

When the belt is first tightened down, go out and drive the car and make 8lbs. Then after about 20 minutes of driving around, I am only making roughly 6.5lbs of boost. I would attribute this to the belt slipping or stretched, but trying to identify an area that may be creating additonal friction/tension not allowing full boost is driving me nuts.

Also, in the previous post I mentioned that the gatorback belt appears to be wearing odd. I have fine rubber throughout the engine compartment, especially around the idler pulley. So I should maybe focus my attention to that area? maybe realign the mounting plate, less the washers on the inside of the plate that mounts to the timing cover?

jpc350z

I have found that for my car to reach 8psi I have to keep it floored till it reaches about 80mph. Don't know at what speed others reach to get 8psi.. An intereseting experiment..As far as belt dust, might as well get used to it.. Mine makes some with the Gates but think by your description that you may be making more..

gspot35

JPC- Boost should come up with RPM...you probably can't make full boost in 1st gear, but every other gear should give you 8psi near redline. I make very little dust if any as do a lot of other people.

Sunset- are you sure you have no vacuum leaks? Is your idle stable for 2-3 minutes straight? You could have your cog belt idler too tight creating too much resistance. If you have belt dust, it's caused by friction. Either by mis-aligned belts or loose belts. Remember the load increases on the s/c as boost builds, so slippage will occur at high rpm where it's hard to see. Good luck in your hunt.