I was talking about the future setup with the shop where my motor is, and the question was raised as to "why not go with a cog setup?" considering I'm looking to hopefully make 16-18# boost with a D-1SC on my setup.

I see people avoiding a cog setup like it's the plague, and am wondering why. It seems like it would definitely take care of belt slippage issues, but is there a higher parasitic loss with it too?? Or is it more of a room and clearance issue?

 

At that level of boost cogs makes good sense. The downside is the same as the upside. The cogs don't slip. That puts stress on everything. Make sure you have a great bracket, a double-keyed damper/hub, and maybe solid motor mounts/engine brace.

 

Definitely going to be a keyed hub, and I would think that the ATI bracketry would be sufficient. I'm going to be running poly mounts as I'd like to refrain from solids.

 

I do not see why people are scared of cog belts. I have had mine for over a year now and have had no problems. My car is hardly ever driven though. If everything is setup inline, the belt is not over tensioned, and a good quality belt is used then it should last for a while. My cog pulley system uses the stock Vortech spring loaded tensioer. I have never thrown or stripped a belt.

 

I was going to this but ATI said it would kill the D1SC but if you do i would run a bigblock snout crank to help with the load if you dont it will get messy

 

How do you mean?? Was that meant as you were going to do the cog setup but ATI recommended against it???

Either way, what we're probably going to do is try running it with the ATI stuff on a 12 rib pulley setup first, and if that doesn't work move to the aftermarket tensioner second, and lastly move to the cog. This is all going to be on an engine dyno BTW, before it goes into the car.

 

what are you talking about? A crank snout issues come from belt miss alignment(ati favorite) and lots of tension on the belt. Cog system does not use as much tension as the Serpentine Set up so its not as hard on the crank/bearings.
I sold my ati set up, i'm going with the Ysi Vortech unit, bracket made by chris sykora and ASP cog pulleys.

 

I run the 12 rib set up from ProCharger with my F1 that makes 22 psi. No belt slippage. Everything was properly installed to make sure that the pulley system was aligned correctly. I have a custom fabricated billet dual keyed hub with an ATI balancer. I really don't see the need for a cog set up.

 

BTW...

Not that I'm an expert on supercharging... far from it...

But I am going to suggest that you add getting a crank with a big block snout to your plans.

 

The regular procharger LT1 bracket leaves a lot to be desired with only 3 3/8" attachment points that use very long aluminum spacers. Two of the mount points are into the aluminum heads. They may have a better cog bracket now, but we had to modify the 12 rib for my cog setup. The best setups use solid motor mounts or a motor plate. Then you can add additional bracing for the bracket from the frame. Until you feel comfortable with it, check your bolts after every run. The good news is dead consistent performance.

 

How are solid motor mounts or a motor plate going to help? Solid motor mounts or a motor plate would be a little rough for a street car. Why would it matter if 2 of the mounting points are to aluminum heads? The blower is mounted to the engine. Motor mounts aren't going to prevent the blower from moving. If you want to add an additional mount from the blower bracket to the head or the block, that'll stop any flex from the blower bracket. I was thinking about doing that, but I am not getting any belt slippage. I have seen number of f-bodies with nearly the same set up as my car and belt slippage is not an issue with the 12 rib set up. I guess we must be lucky.

 

The solid mounts are rough for the street. But they allow you to triangulate a brace off the frame. A 3/8" bolt into aluminum just isn't very strong.

 

When I called ATI to get a few opinions they told me that the transmission on the D1SC couldn't handle the stress of a cog drive because it wont slip.

The grip of the cog belt will rip the crank snout right off if you dont use the big block snout setup on the crank. it is not a pretty sight at all. It happened to a freind of mine and it ripped the opti spark off all of the plug wires, temp sensor wires, maf wires you name it, it tore it all off the car. It also damaged the heads because the timing chain came off and sent the valves into the pistons which inturn bent the rods.


so in a nut shell thats why you want to run a big block snout on your crank only a few hundred bucks more for the crank and ATI balancers also offers the timing cover you will need

Steve

 

Ok, you piqued my curiousity. Explain the whole "big block snout" part. Is that a crank with a larger machined snout, and who sells these???

 

hows that? Crank drives the blower not othe way around. I snaped my snout early this year when the car was idling in the driveway with a 12 rib set up. Most of the time like i said earlier the Tension on the belt and missalignment of the belt is what does it. I noticed that with the12 rib set up you really dont have a belt choice the one that fits is very tight with no tension on it. It creates a PryBar effect kinda if you were to take a pry bar and put it on your crank and put constant pressure on it, the more you tighten the belt the more stress on the crank there is.
There is plenty of people that run very high boost on lt1s with stock hub, you just gotta be very carefull setting it up.