SCH Dual Idler/Cog Track Results.

[itlkick]

Although my quarter mile times were not what I wanted I was VERY happy with my new dual idler setup. I made 8 passes and did rip the cogs of a few belts but I did not throw any belts. One thing I learned was having a cog belt loose is not good - it must be tight just like a serpentine but just not damned tight like a serpentine making a lot of boost. When I had the belt loose (like I heard from some "experts" to do) I ripped the cogs off every time.

As far as quarter mile times? Well I could not get any traction. I ran 8 passes with all being between 10.5xx and 10.7xx. Every run was feathering the throttle in 1,2, and D with full throttle only after I was past 100 MPH. If I hit it before that i would spin. Maybe at a better prepped track or with a different set of slicks I can reach my unobtainable 9.xx I am looking for...

Pic for those interested (not like I haven't posted it a million times....)

[5150 LX]

Cool deal I can't even imagine driving a car that'll haze 'um at 100 mph

[BLOWNBY]

IAN,

Probably dumb questions but I didn't find the answers on the site with a quick look.

Do the dual idler setups come with the idler pulleys? If so is there a difference in the idlers between a cog and serp. setup? Are the idlers billet? Any cost difference between a cog or serp setup?

Also, you don't make cog pulley's do you. Any plans to?

Thanks

[root]

Hi Blownby,

If you buy the dual idler system it does come with 2 Billet idlers with top of the line bearings installed. I was unsure if the idlers are different, but I spoke with another user and he said that a 8 rib smooth idler and a cog idler are the same. Maybe someone else can confirm this for me? We do offer different spacers to get the belts lined up.

We do not make cog pulleys right now, but it may be something I look into in the future. I need to locate a model and go from there.

Ian

[BLOWNBY]

If you look at the idlers up a few post, are those what come with it or are they aftermarket. Because, those would help to keep the cog belt aligned more than a normal wall-less serp idler.

[itlkick]

If you look at the idlers up a few post, are those what come with it or are they aftermarket. Because, those would help to keep the cog belt aligned more than a normal wall-less serp idler.

No, those are Vortech idlers. The 8 rib idlers will probably work with an ASP cog setup but not with a Vortech cog setup. The Vortech cog pullies are 35mm wide and the ASP are 30mm.

[root]

Hey itlkick..

So if I were to make a idler that us 35mm wide that should be ok for a cog setup? I can make it 35MM with or 35MM + sides. The cog idlers use double bearings correct?

What is the dia of the Vortech idlers?

Ian

[itlkick]

Hey itlkick..

So if I were to make a idler that us 35mm wide that should be ok for a cog setup? I can make it 35MM with or 35MM + sides. The cog idlers use double bearings correct?

What is the dia of the Vortech idlers?

Ian

I will measure my idlers tonight and get the info to you. I will also measure the spacers as I had to use a washer to get the spacing right.

[root]

Perfect thanks. I think I have your measurements for the spacer, but a confirmation would be great.

Ian

[itlkick]

Perfect thanks. I think I have your measurements for the spacer, but a confirmation would be great.

Ian

Pulley measurements:

Inside lip (inside edge to inside edge): 1.400"
Outside lip (outside edge to outside edge): 1.603"

Lip diameter (full width of pulley): 4.333"
Belt area diamter (inside lip): 3.670"

Spacer (the one I made with washers): .600"

All measurements done with a dial caliper.

The bearings are a dual design. From the outside of the lip to the edge of the bearing (depth) is .430" (as close as I can measure).

[itlkick]

One more thing (for what its worth), I am considering switching to a custom 50mm setup. If I do that I will first try one idler pulley to see how it holds up.

I never throw a belt anymore but occasionally rip the cogs off the belt (about every 4-5 passes). Vortech said the YSi spinning as hard as I am spinning it really should have a 50mm belt. Besides - a 50mm belt will look really cool. I have my engine set back 1" and have relocated my water return neck on the radiator so I have room (barely) for a 50mm belt.

If I do that I will let you know how it works out (spacer sizes, if a dual idler was needed, etc.).

Anyone interested in a barely used Vortech cog 35mm cog setup? 73 tooth crank with mondo retainers. 27, 28, and 30 tooth supercharger pulleys. 4 belts (3 new). 2 idlers.

[BLOWNBY]

One more thing (for what its worth), I am considering switching to a custom 50mm setup. If I do that I will first try one idler pulley to see how it holds up.

I never throw a belt anymore but occasionally rip the cogs off the belt (about every 4-5 passes). Vortech said the YSi spinning as hard as I am spinning it really should have a 50mm belt. Besides - a 50mm belt will look really cool. I have my engine set back 1" and have relocated my water return neck on the radiator so I have room (barely) for a 50mm belt.

If I do that I will let you know how it works out (spacer sizes, if a dual idler was needed, etc.).

Anyone interested in a barely used Vortech cog 35mm cog setup? 73 tooth crank with mondo retainers. 27, 28, and 30 tooth supercharger pulleys. 4 belts (3 new). 2 idlers.

With the cogs and ysi, what type of boost are you seeing, and at what RPM's. I am seeing about 20+ with a 2.7 RR/ 8" at 6,200 RPM's on a 351. My shift point is 6,200-6,4000. I have considered going to cogs. Not sure but I may be interested in your setup. I have had pretty decent luck with the RR pulley thus far.

[itlkick]

With the cogs and ysi, what type of boost are you seeing, and at what RPM's. I am seeing about 20+ with a 2.7 RR/ 8" at 6,200 RPM's on a 351. My shift point is 6,200-6,4000. I have considered going to cogs. Not sure but I may be interested in your setup. I have had pretty decent luck with the RR pulley thus far.

I am seeing around 22lbs of boost with the 73/27, 20 with the 73/28, and 18 with the 73/30.

When I switched to cog pulleys I made almost 100 more horsepower than I did with the same ratio of serpentine pulleys (no slip) plus I made more low end torque. A cog makes more power.

A cog pulley is more work. Serpentine belts can slip which drops power but they don't rip cogs off and stuff like that. I could never go back to a serpentine belt after having a cog setup but I don't think cogs are for everyone...

More info: ASP cog pulley setups are 30mm wide. The extra 5mm with the Vortech setup makes a real difference. With a 30mm setup (ASP) I was not able to make a full pass without destroying a belt.

Vortech has said that is primarily due to my YSi. It moves a lot of air and therefore takes a lot of power to spin. A T-Trim or even a YS-Trim is not as hard on the belts.

[BLOWNBY]

What RPM's are those boost 's at. HP?? Did you make more boost with the cogs as well as the increased hp.

If you look in my images I have a copy of my dyno sheet comparing the 2.7 and 3" SC pulley. These are the HP numbers I am making. Any ideas as what to expect with the cog setup from these. The belt started to slip at 6,000 plus. The belt couldn't be tightened any more du to the bracket hitting the bolts. But I seem to be O.K. so far with a shorter belt.

Would a 77 & 30 tooth be a better setup than a 72 and 27/28. As far as throwing the belt or ripping teeth off??

[itlkick]

What RPM's are those boost 's at. HP?? Did you make more boost with the cogs as well as the increased hp.

If you look in my images I have a copy of my dyno sheet comparing the 2.7 and 3" SC pulley. These are the HP numbers I am making. Any ideas as what to expect with the cog setup from these. The belt started to slip at 6,000 plus. The belt couldn't be tightened any more du to the bracket hitting the bolts. But I seem to be O.K. so far with a shorter belt.

Would a 77 & 30 tooth be a better setup than a 72 and 27/28. As far as throwing the belt or ripping teeth off??

I see maximum boost at around 6,200 RPM. On the dyno I run to 6,800 RPM (at the most).

It suprised me how much more power (torque and horsepower) I made with cogs. If you think it is only slipping at 6,000 RPM just wait until you run cogs. The thing is you slip more on the street than you do on a dyno so the real world advantage is even greater than the dyno results - which are amazing.

The problem with the 77 tooth is you have a higher belt speed which can cause problems. I had more problems (with my ASP setup) when I had the 80 tooth than I did with the 74 tooth. I thought the same thing, extra cogs = better strength. It did not work that way.

I think either the 77 or the 73 would be fine. When I have my custom 50mm setup made I am going with a 75 - the primary reason is to make the pulley just a bit bigger so the belt will clear my electric fan. If I wasn't worried about it hitting I would go with a 73 or 74.