B4Ctom1

I have used the procharger because ASP sells cogs and pullies for the paxtons and vortechs. What is left is for some of us to come up with a solution for ATI's. Before anyone gets too carried away here, I believe ASSC offers some pulleys and that might be worth atleast checking into. but my question is: what cogs, pullies, RPM, boost level are you running your procharger? Im curious to know your impeller rpms (engine rpm vs. pulley size ratio vs. unit internal rpm = impeller rpm) and resultant boost from this RPM. Maybe even the temperatures this is causing in your intake? how well is your intercooler helping? Are you running race gas? were you forced to run alcohol injection? can you drive it around? what kind of compression did you build for? I figure there has got to be an RPM for prochargers where it makes no sense to spin them above it because it just makes the air too hot or basically they loose efficiency? on a D-1? D-1sc? P-1sc? p600b?

Kendol

Willie is offering to help us cooridinate a group purchase through his source. How many of you guys with P1SC and D1SC Prochargers would be interested in putting together a GROUP PURCHASE for COG drives???????????????

Willie quote:

"BTW, it's not the cogs themselves that are "expensive". It's the other parts that have to be fabbed. If you guys can generate enough interest in a GP, I'll be happy to coordinate it through the source where I got all my parts."

So come on, lets see how many of you are interested!!!!!!

Kendol

Assume we do generate enough interest, what all was necessary? Most of us have seen the pictures you've posted of your car, this is what I've seen:

1.) COG crank pulley
2.) COG blower pulley
3.) COG belt
4.) 2 antiflex brackets (one to front header bolt and one underneath to the grounding strap bolt)
5.) Removal of one idler pulley

Anything else? Can you give us an idea of what you paid for the respective parts? How hard was it to convert over?

Willie

iTrader: (1)

That being said (above), here is some information as to what's available.

ATI stocks crank and blower cogs for the P1SC & D1SC:

Crank: 66, 73, 77 & 81 tooth
Blower: 32 to 58 tooth in 2 teeth increments

For some reason beyond me, the unit of measurement for cogs is metric. And to calculate impeller rpm, the same formula is used as with ribbed pulleys, except pulley diameter is not used. Instead, the number of teeth is used. The formula:

(Crank tooth #) x (engine rpm) x (blower step-up ratio) / (Blower tooth #) = Impeller rpm

The P1/D1SC step-up ratio is 4.1.

What needs to be custom fabbed is the crank pulley adapter and idlers. Only two idlers are used with the cog setup. Also with a cog setup, it is absolutely mandatory to stiffen the blower bracket as much as possible. This is accomplished with three braces. One is ATI's (top near the alternator). The second connects the bottom front of the block using an existing driver's side serpentine accessory bracket bolt to the bottom of the blower bracket (bolts to the hole previously used by the lowest idler). The third brace connects the bottom of the blower bracket (just below the blower itself) to a header stud. I have pics of the braces if anyone wants me to post them. It is these pieces that cost $$$.

Now here's the kicker: The problem with cogs is the limited availability of cog belt lengths. The only one that can be used is 1600mm long. The method used to tighten this belt, given different pulley diameters, is to use different sized idlers and possibly a slight repositioning of the upper idler (requires drilling a hole in the bracket).

I am using the 81 tooth crank and 32 tooth blower cogs. This combo produces the most boost possible with the available cogs. It works with the 1600mm belt and two custom fabbed idlers (small) with plenty of tensioner adjustment remaining. Also, I know the 77 & 34 tooth combo will work with the belt too. Other combos will require idler repositioning and/or a larger idler.

And another kicker: Because the lowest idler is eliminated, the belt's routing is different -- the primary fan motor gets right in the way!! The only solution is to replace both stock fans with Flex-a-lite's dual fan (with shroud) setup. These are ultra-thin.

I'm sure I've forgotten something, so as I remember, I'll post down the line.

Willie

Kendol

What about pricing? Odd when I talked to the customer serivce ATI troll, he was unaware of COGS offered for our kits. Maybe Dorian can straighten this out. I'll call him tomorrow to get the most up to date pricing.

Willie

iTrader: (1)

What about pricing? Odd when I talked to the customer serivce ATI troll, he was unaware of COGS offered for our kits.

Well in a way, he was right. There is no kit for our cars that contain cogs.


Maybe Dorian can straighten this out. I'll call him tomorrow to get the most up to date pricing.

You can possibly get full retail pricing, which is what he'll give you. The retail cost is very similar to the 12-rib pullies.

You might want to contact Dave Back at dback@tenperf.com for individual cog costs. I'm sure they will be cheaper. But before we do this, let's see what kind of interest there is for the cog conversion. Once I know how many are interested, I can contact Dorian and/or Dave to determine viability for a GP.

Willie

Kendol

Anyone interested?

B4Ctom1

I want to use a cog belt like the mustank guys which is no wider than the 12 rib, which puts me back into the (make my own) category. since the idlers run on the back of the belt they wouldnt need to be replaced nor would the fans. if i do it that way...

Willie

iTrader: (1)

I want to use a cog belt like the mustank guys which is no wider than the 12 rib....

The cogs ATI supplies (and the ones I have) are used in the Mustang kits. There are no "F-body" cogs. That's why the crank cog needs a fabbed adapter, as well as fabbed idlers. The 12-rib is 1.75" wide. The cog (50mm) is 1.97" wide.


....which puts me back into the (make my own) category. since the idlers run on the back of the belt they wouldnt need to be replaced....

Idlers for ribbed belts differ from the cog belt. The cog belt idler has a much taller shoulder, which is necessary to keep the belt from flying off. The cogs themselves do not have shoulders, like the ribbed pullies.


nor would the fans.

Based on the above, you will need the fans.

Willie

B4Ctom1

if this fabricated set pans out would you be interested in seeing it? I still need to know what kind of RPM I would or wouldnt want to run with the P-1sc

89ProchargedROC

Just a FYI....if you contact ASSC and talk to Larry about the cogs he makes for ATI cars i do believe you are going to have to change out your fans to the perma-cool thin-line fans (only 1/4" thick but still pulls 2200cfm)

I've seen his setups and they are beautiful

Blown406Bird (Tory Hess) has a whole setup from them including custom F1-R bracket. You can see some pics of his setup here:

www.rhodescustomauto.com

Willie

iTrader: (1)

Here's my "kit" from Larry @ ASSC:

Kendol

Wish more people were interested looks like most are happy with their existing setups. Maybe we'll see some more action in a week or so

That setup looks great Willie. Missing the ATI antiflex bracket though, right? Thanks for taking the time to take a picture of it off the car for all of us who are interested.

Hoprfully more people will get interested

Jack G Jr

Yes I would be interested in a cog set up.Even though I dont have my s/c yet from my seach of this site belt slippage seem to be one of the big problems So why not just eliminate the problem.So count me in

Kendol

Thats 3 anymore?

B4Ctom1

thanks for showin me too Willie

Jeff 91Z28/L98

I'm running the D1SC with 12lb pulley (3.70") and with the belt slippage I'm only getting 8 to 9 so I'd be VERY interested in the cogged pulley setup. Switching the fans out sounds like a PITA but hey, I can live without the belt slippage. I'm glad someone finally addressed this, I've been searching the internet for the last couple of weeks looking for cogged pulleys or places that could custom make them. I just wasn't sure what dimensions would be on a cogged setup. I'll keep checking this post to see if more people get interested.

Jeff 91Z28/L98

I'm running the D1SC with 12lb pulley (3.70") and with the belt slippage I'm only getting 8 to 9 so I'd be VERY interested in the cogged pulley setup. Switching the fans out sounds like a PITA but hey, I can live without the belt slippage. I'm glad someone finally addressed this, I've been searching the internet for the last couple of weeks looking for cogged pulleys or places that could custom make them. I just wasn't sure what dimensions would be on a cogged setup. I'll keep checking this post to see if more people get interested.

blownSS

This is my first post... I have been sitting back for the past year reading and learning. I have a D1SC and I too am interested in the COG setup.

a73camaro

P600b on a 383 with an aftermarket TPI style intake. This is a custom setup in a jet boat. I'm using a six rib belt with a 3.25" pulley on the Procharger and a 7.28" crank pulley.

The blower step-up is 3.36 (74/22 gear teeth ratio). Because of the jetdrive, engine RPM is limited to 4500 RPMs.

I was getting about 6 psig boost at full throttle. The air temperature of the boost was about 140°F with ambient at ~85°F.

Blower speed is 7.28 x 4500 x 3.36 / 3.25 = 33900 RPMs

FWIW, no intercooler and compression ratio measured and calculated to 8.6. Running 91 octane (highest pump gas octane in Denver, CO)

B4Ctom1

Im interested in a cog to avoid the massive side load of the crank from overtightened belts, A machinist friend says I am just trading one kind of abusive stress for another kind.

A friend of mine that races mustangs runs a cog. We had a discussion about launch techniques, as it relates to stalling against the converter on a trans brake. We discussed the option of helping to keep the tranny from slipping while in the trans brake by having the staging revlimiter stuttering a few rpm below the maximum stall. He said he broke some crank snouts that way and quit doing it in favor of just abusing the tranny. He said the stuttering of the engine causes stuttering of the blower and that being transmitted through the belt snapped the snouts. He quit doing it and they quit breaking.

any thoughts on this stuff?

Kendol

So many views and so little interest, I'm getting worried!!!!

Come on guys, money maybe short, but if you can get a really good deal by joining in on a group purchase what's the hold up?

Nothing in this world is free, but group purchases tend to be the next best thing!!!!

biggtime

Does anybody know the diameters of the crank/cog pullies? Is there a formula (tooth X ____= diameter) I have clearance issues.

Crank: 66, 73, 77 & 81 tooth
Thanks in advance

Kendol

Just like with the 12 rib setup, there WILL BE clearance issues. You can buy slimline Flexlite fans to open up the necessary space. As for a formula for actual size, hopefully Willie will chime in.

Willie

iTrader: (1)

It's simple to get a fairly close estimate on pulley diameter. Let's use an 81-tooth crank cog pulley as an example. We all know (hopefully) that the circumference of a circle is 2 * pi * r, or

pi * d

One "cog" is 8mm long. So 81 * 8 = 648mm

648 = pi * d

Solving for d:

d = 648 / pi = 206.37mm

206.37mm / 25.4mm/in = 8.12 inches!!

Kendol

Nicely put Willie!!!!! BTW, thanks for checking back in.

CRZYTRN-92Z28

Sorry I'm late, but i would definetly be interested.

I have the D-1SC and the flex-a-lite fans so I would be styling.

88GTAinRI

I am interested. I would like to know how much we are talking about first though. Fans, cogs, belts, brackets, idlers, etc. I have a P1sc with the 8 rib set up. I want a kit, in a box, that I open and install. Also would like to know how you guys are running your upper radiater hoses with such a wide set-up?

B4Ctom1

there will not be a kit in a box with exception of a few pieces which might come to gether like the actual pullies and idlers I would suppose.

there are several posts on the subject of hose clearance for prochargers, I clearanced mine for a 12 when I installed mine with the 8. I intend to run a cog, I still havent sat down with my machinist to discuss the details. I need to decide what cog tooth profile size and type I want to run, and look at whats available.

Jack G Jr

Hey guys just finished talking with Larry at ASSC he told me he sells his setup for $750.So why not get a gp together and save a few dollars.He did suggest doing a double keyway on your crank if you are pushing alot of boost. Come on guys

B4Ctom1

UM! no

blownSS

If I could save a few hundred off the $750 count me in!

88GTAinRI

$750 is too rich for me. If I decide to run more boost in the future I will keep it in mind. I hear boost is addictive so I am sure $750 will look sweet in the future.

Jack G Jr

750 is the price for an individual purchase but if we could get it for a little cheaper thourgh Wille then why not?

a73camaro

I know this is a Ghetto idea, but is there any chance that timing belt cogs can be used to drive a centrifical supercharger? You can get a 2-1 overdrive, but I believe that you needs to obtain more of a 3 to 1 overdrive with the cogs.

Maybe different cogs from different engines can work.

Just a thought....

CRZYTRN-92Z28

Spring loaded tensioners are looking real good compared to a $750 price tag. Not to mention the belts cost like 100$ a piece. If we can get that price down i'd be interested.