i may have to try this. still having belt issues with the f1a and sdce. 7.25/3.70 pulley

 

Wow... I thought Procharger was making them this way now. Ive been running that same setup for a good 3yrs now.... through the shop I bought my Procharger I was told that I was getting a prototype J bracket (from Procharger) with a extra idler on it for better belt wrap. I figured that since it worked so well for me that they wouldve started producing them after that, I never checked to see if they actually did. Guess not!

I actually had the SDCE setup ready to install when the owner of the shop I bought my D1SC through told me to try out the prototype J bracket.... so I sold the SDCE stuff and went with the new J bracket for hundreds less.

Ive had ZERO belt slip issues since I installed it.... only had to replace one idler bearing but that was it.

 

Awesome! Glad to hear its already a proven design! This is the way the fbody procharger setup SHOULD be!

 

It really doesnt get any better than this.... the belt wrap is insane. I have the belt torqued down to the point where there is only about 1/8" between the belt surfaces.

Youre right... Procharger should have made them this way from the get go.

 

Do you know the diameter of the stock LS1 idler pulley? I am hoping that the idler pulley from my F-body LT1 will be the same diameter.

EDIT: Never-mind, I just went out in the rain and measured it. It was hard to get an exact measurement with the belt around it but I am guessing that it is a 3" pulley. The LT1 pulley diameter is just over 3.5" X 1.2" wide but the bearing will fit on the modified standoff. This 3.5" pulley may benefit me since I am running a 6 rib setup with the stock 6" crank pulley?

 

Breaking the tires loose at 90 will make the *** hole pucker really quick Might have to swap out those rubber bands for some real tires.

 

Thought I had mentioned it somewhere in here already, but oh well, the stock LS1 idler is 3.00" diameter. The bigger diameter you put on the standoff, the less adjustment you will have for the tensioner, so keep that in mind.

No doubt! Yea, I'd like to get some 305/30's next time around. I'm sure they will fit the wheels since they are 10" wide. And actually, when I was having these 285's mounted, my buddy switchin the tires measured, and they are really 10.5" wide, so I bet 305's wouldnt be a problem at all.

 

Heres a few pics...

 

Your crank pulley is 7.65" and mine is a 6" so I should have no problem. I am pretty sure I am going to have to go with a longer belt.

 

Very cool!

I think I still have my idler pulley that came with the factory Procharger bracket set up before I sent it to SDCE. That should work out for the second idler. Although currently I am not having any belt slip issues.

 

Nice pics man! So are you utilizing one of the other bolt holes above the extra idler? Or are you using just 4 bolts to hold the head unit to the bracket?

 

If at one time there was a prototype j-bracket utilizing a second idler pulley I wonder if ATI ditched it because of the access issue to one of the head unit to j-bracket bolt holes?

 

I sketched up the system in inventor just to get an idea on what the belt size would need to be for my 3.7 pulley. I did the best I could by just measuring pictures that I had as I didn't want to remove the procharger again just to measure, but I think I am pretty close. If nothing else, this should give a pretty accurate ballpark idea of belt length. Just for grins, I also measured the belt wrap on the head unit and the crank. Here are the results I measured in inventor:

Crank Pulley/ Head Unit/ Tensioner/ Idler/ Belt Length/ SC Wrap/ Crank Wrap

7.65/4.25/2.5/3.0/42.93/229°/272° <--(this belt length verifies my CAD file is pretty damn close- reference my original measurement was 42.75-43.125 with a tape measure- this falls smack dab in the middle of those measurements)

7.65/4.25/2.5/2.5/42.62/225°/266°

7.65/3.7/2.5/3.0/41.85/221°/272°
7.65/3.7/2.5/2.5/41.56/217°/266° (looks like I'll possibly be able to use my 41.5 belt with this setup once I'm ready to pulley down)


7.65/3.55/2.5/3.0/41.56/218°/272°
7.65/3.55/2.5/2.5/41.28/215°/266°

7.65/3.4/2.5/3.0/41.28/216°/272°
7.65/3.4/2.5/2.5/41.00/213°/266°

7.65/3.1/2.5/3.0/40.72/212°/272°
7.65/3.1/2.5/2.5/40.45/209°/266°

Again, remember that the stock procharger idler is 2.5", and the stock accessory idler is 3.0. Hope these results help for some of you guys. If anyone wants me to put in any more pulley sizes, let me know and I'll get them for ya.

*edit: I graphed the belt sizes I have done already and plotted the formulas for the 2.5 & 3.0 idler configurations. The chart can be seen here if you want. But basically, just use the following formulas to find belt length:

For 2.5 idler: Belt Length = 1.8897 * (SC pulley diameter) + 34.579

For 3.0 idler: Belt Length = 1.9248 * (SC pulley diameter) + 34.739

The above formulas are only for 7.65" crank pulley and 2.5" tensioner pulley.

Here are the Gates and Goodyear Gatorback belt sizes:

Gates belts here:

http://www.gatespowerpro.com/Comerge...TOKEN=54684150

*dang, cant get the direct link to work. Click on the link above, then click "Belts", and on the next page, click "Micro-V® AT® Belts". Then, type the size in the search field you are looking for. For example, to find all the 42.X" belts, type "K08042*"

Also, make sure to click on the part number of the belt you are looking at to verify the effective length. Sometimes it is slightly different than the part number would suggest. For example, the effective length of a K080427 is not a 42.7" as you'd think, its really 42.87".

List of effective belt lengths in the typical range for Gates belts: 40.13", 40.79", 41.50", 42.40", 42.87", 43.36", 43.62"

And incase you cant find something close there, also check out the goodyear gatorback belts here:

http://www.goodyearep.com/ProductsDetail.aspx?id=3128

*make sure you are looking at the effective length of the belt here as well.

List of effective belt lengths in the typical range for Goodyear belts: 40.00", 40.75", 41.50", 42.50", 43.50"

 

Ya know I dont know any different from a J bracket without the second idler.... my D1SC is only held on by the 4 bolts. Again... Ive been running it this way for a few years now with no issues. I suppose we could devise a much smaller idler so the 5th bolt hole would be accessed.

 

I already did that. 1.75" diameter is the largest pulley you can put over the bottom stand off and still get to the last bolt hole on the bracket.

 

you sir are a good man could you please help me with belt size?
crank 7.25
head unit will be 3.40
thanks man

 

I can't picture what the 0.59" diameter section of the standoff is for? If the pulley rides on the 0.668" diameter section why mill that short section down even more? Please help me out.

Also how do you keep the pulley from rubbing on the bracket? I see Avengeance has a slight gap between the edge of the pulley and the bracket, how is this achieved?

 

Ricky- I'll check that tonight for ya when I get home man.

The answer to both your questions is a spacer (I used washers). You can see them here: http://i24.photobucket.com/albums/c1...t/PIC-0288.jpg

 

thanks Chad!

 

So technically the 0.59" diameter section is not necessary?