question for you.... If I buy the sprag setup, would it be trasferrable from pulley to pulley (different sizes) by my machine shop? For instance, if I bought a 28t and a 30t and a 32t, would I have to buy 3 sprag setups or just one and have it be transferrable?

 

the way I'm making them the center piece that houses the sprag can stay on the s/c if you wanted and the outer cog teeth can be swapped from 28/40 teeth.the cog hat(that's the only thing i can think of calling it) will slide onto the sprag housing guided by 2 keyways that also prevent it from turning under belt load and then thats held on by 10 button head screws around the front of the pulley .it makes more sense to make them this way since the sprag is the expensive part so if a guy wants to try a few different sizes it wont cost that much . also i just found some ceramic bearings that i am going to use in the sprag housing for a few obvious reasons ,there stronger they run cooler and they weight less ,the lighter i can make this thing the better.I think i got a idea that will let you run the 30 or 35mm belt on the ysi with out worrying about belt issues i just need to see a pic of your s/c set up .just a update on my first sprag pulley i made and put on my friends stang ,its been a few weeks now and its friggin working perfect .

 

keep us posted. waiting for the release.

 

Put me on the list for 1. Keep us posted for release. I am putting together a cog setup for my F1R on my Silverado SS. Im going to run just the blower with the cog belt and 6rib serp behind it for the accessories.

 

How wide of a cog belt you going to use I'm guessing a 2 inch? also what tooth count do you want for the cog ,i know the f1r is a friggin monster blower .have you got the cog set up yet ? i can help you out with that if you want ,my friend can build you any cog set up you need for a very good price.I will keep you posted about the sprag pulley but just a update ,another day of abuse and it still working great

 

Shiver,
How about some pics of what you have to date.

SilveradoSS,
With regard to the cog / serp combo, you need to read on the internet regarding the torsional loading of placing the positive (cog) drive further out off the end of the crank. This is one reason that you will note that people who make dedicated blower drives move the serp slightly out and place the cog inboard on the crank. An F1R is the same basic blower as the D1R (read as big a$$ blower), yet self contained and some other slight changes. Food for thought...
Aaron

 

Since your already going to have the cog belt,
are any of you adding a drysump?

 

Or you could use a crank snout to blower brace. Bob Kurgan makes a nice one. Maybe on the truck there would be enough room to use one.

 

I have not bought anything yet. I am still trying to decide what will work best. Iv been reading up on just about every site to get as much info as i can. I was thinking 8 rib but it would be a 118" belt for me and it would have to be ran very very tight like the Mustange Renegade guys do to spin a F1R. So I read up on cog setups and have come to this.

AKS Racing the stress on the crank snout is a concern. Not sure what to do yet. I have read where its caused problems on LT's but have not found much on the LS's. I was going to try and setup the crank like this
and my blower is already high on on the pass side I just need to move it forward and end up looking like this. with the 6rib behind the cog. Nothing is set in stone Im open to any suges. I would like to run everything on the cog belt but have read where that has not worked out so well with pulleys braking off. Im still undecided.
qwiketz I was also looking at the brace to help combat the stress on the crank.

 

From the pics i see i think that will put way to much stress on the crank snout ,the crank cog pulley is way to far ahead imo.i would run the cog pulley first and then the 6 rib in front of it .you can also run everything off cog pulleys with no problem ,i know a few guys who are doing it ,i will be running my crank,w/p,alt,p/s,a/c,s/c,two tensioners off 1 cog belt .check out the pics of timo's''rokka'' set up it was built from my cog system .aks has a good point the belt that far forward will put a lot of stress on the crank snout ,i would run the cog pulley first as far back towards the block as i can get it and the 6 rib in front .btw i can hook you up with the cog/6 rib pulleys you need to do it right.

 

How are you not hitting the frame rail infront of the engine?

 

maybe Aaron could chime in on this.... with the mid size prochargers(f1r, f2), can you get away with a 30mm cog or do you need a 50?(I'm just curious) With the vortechs it's my understanding you definately need a 50, however you're dealing with a third less teeth to grip the belt so it makes sense.

 

OK here is my experience.

I have run several Vortechs and many ProChargers. When I went to design the large "street" blower system I run now on my Vette, I selected the ProCharger (D1R) in part due to the step-up ratio. With the much larger step-up ratio, the size of the driven shive (blower pulley) is much larger which means that the belt contact area is significantly improved. This is better whether you are talking about a 6 rib drive or a cog drive. I will be the first to say that I have not run anything larger than a 6 rib in a Vette (though I have done an 8 rib and a several 12 ribs on F-body's). With the larger blowers (and the larger step-up associated), I have not had a real reason to go beyond 6 rib. The D2R on the other Vette uses a wider drive, but it does not use the factory accesories and is not in what would be termed a "street car".

I did run a 1.18" cog drive (30mm) on my '87 for quite some time with no issues related to the belt, however, I did wind up damaging the transmission over time due to the positive engagement of the cog. If you look at a factory serpentine, when the engine slows rapidly, the idler releases some tension, and the belt does slip to some degree (read as built in transmission protection ). The gearbox on a blower is quite expensive to rebuild. I have since shelved the cog and continue to run with the 6 rib. It provides more than enough boost (regularly 26+ psi; few times 28+), which is way more than any street car needs. The cog system had it's own dedicated drive inboard of the factory 6 rib, so that there was no excess torsional forces applied at the end of the crank. As a side note, I have a friend who lost the BBC machined snout off the crank on his big cube SBC due to a blower "hiccup". Very expensive.

If there are further questions, feel free to post them up, and I will answer, as I happen to be in town this week.
Aaron

 

Just some background on my build. My setup is a 2003 Silverado SS AWD with F1R, built trans, 3600 stall, Texas Speed 408 fulley froged with ported L92 heads and LS3 intake, 233/239 112lsa cam at .605 and .600 lift, supporting fuel system plus many other mods. I am not sure I can make 16psi on this motor with a 8rib 118" serp belt. The only guys I know of that run 110" 8rib serp belt are the Mustang guys and they say get the belt so tight you think the crank will brake off and then give the tensioner a few more turns. They make 20psi+ but go through belts about every other run. I know the 6rib will not spin it. ATI sells a 8 or even 10 rib pulley kit for my truck for around $1000. Now that would be easy to do but Im not sure it would spin it without slip. I will be shifting at 6800rpms. The Bracket I have is not like the LS1 with a short 8rib belt running the blower. My setup is one long 118" belt for everything minus AC. I just want to do this once with either 8rib or cog. I just though a cog would get the job done. My goal is to break the Silverado SS record of 11.2 in the 1/4 on street tires. I know thats slow but these are street/strip trucks weighing 5400lbs. We are All Wheel Drive on top of every thing else but cut 1.6 1.58 60' on street tires. I know I know this setup would be awsome in a car but I like trucks. Any ideas would be great.
Thanks Aaron

P.S The top pic above is a LSX with a F2 going in 2000 Fbody and the botom one is prochagers F1R small block chevy setup.

 

This thread still lacks pics of the sprag. Hmmmmm....

 

you are trying to sell something.... pics!

 

yeah I would like to look at the sprag and cog job as well.

 

I just posted pics in a new thread in this section

 

just a update on the testing of the sprag pulley on a 347 stroker, 88 mustang running a procharger d1 blower .he has over 4000 kms /2500 miles on the sprag pulley and we took it off today so i can take it apart and check it out and it was excellent ,no wear,no metal shavings,no play ,it was all within specs .since i installed the sprag he has been driving around with a spare belt and just a regular cog pulley in the trunk in case the sprag pulley fails,today he left that stuff at home It's working great i am really impressed with how well it performs .I got the procharger sprag pulleys all worked out from 32-45 tooth and with 30/35mm and the 50mm wide cog belt.I'm also working on the vortech set up now ,i called the place that made me the sprag today and they are going to custom machine a sprag to my specs for the vortech/paxton blowers that will allow me to go as small as 25-26 tooth pulley .im hoping very soon my friend will get a few of each done for me on the cnc machine's .

 

Let me know. Do you have any idea of pricing?