jsavoy

Two quick questions...

1. I'm looking for a smaller pulley for my P1SC, anyone know where I can purchase them besides ProCharger?

2. I read an article/post that noted for every .15" you go decrease your pulley size, you increase 2 psi. Any truth to this or .

Thanks in advance...

jsavoy

Nada?

AKS Racing

1) www.aspracing.com

2) BS no hard fast rule for driven pulley reduction to boost increase. Many factors influence boost increase.

jsavoy

THANKS for the link/info...

Brand-X

There are a number of places that sell blower pulleys (e.g., slotted, tapered grooves, etc.). As for the .15" resulting in 2 psi boost...not sure how a statement like that can be made as each engine represents differing airflow characteristics.

jsavoy

BrandX, thanks for the response. I've been looking but have been unable to locate a 3.25 - 3.5" gooved pulley for my P1SC. I keep reading that "there are a number of places that sell blower pulleys" but haven't found one yet. I looked for @ 30 min last night on the website posted above and could not find a grooved pulley for a P1SC. I'm still looking, but I will probably call them.

If you know of a site(s), post a link for me...thankx JS

AKS Racing

Did you contact ASP? Reichard Racing? There are others, but these are at the top of my list.

Brand-X

What AKS said above...here's the site for their slotted pulleys:

http://www.reichardracing.com/pulleys.php

Last year at PRI, ATI had a sprag blower pulley at their booth. It was in prototype but they might be selling them by now. If you have a stick car, it might be worth looking into.

http://www.atiperformanceproducts.com

Also, why dont you want to buy a pulley from Procharger? Just curious.

jsavoy

IMHO, Their customer service/tech support have been poor. I just don't want to deal with it if I can avoid it. Thanks again for the links and info...

BTW, I have an auto and I'm trying to get more belt wrap as well as a tad bit more boost. I'm looking at Reichard Racing's site now. Again, Thanks Brand X and AKS Racing...JS

AKS Racing

Have you done the calcs on MIS (max impellor speed)? You may find that you are at your limit currently, or you may find that you can go much further with the driven shive reduction.

It is important to do the tech work behind the change. ASP pulleys atr slightly cheaper than ProCharger, but I typically just order from ProCharger.
Aaron

BlowerWorks

Hi JSAVOY, Greg from BlowerWorks here. I have blower pulleys for you. My pulleys are a little unique in that they utilize a keyed tapered collet. This allows you to place the pulley on the blower shaft wherever you want, then lock it into place with three 10-32 machine screws. This way you can align the pulley/belt as needed. I stock many sizes in 6 and 8 rib. Best regards, Greg

jsavoy

AKS,
I believe that I have the correct formula. Please take a look and let me know:

(crank diameter/blower diameter) x RPM x 4.10 = impeller speed

jsavoy

Greg, well now I feel ... I always associated you with Vortech, my apologies. As much as I remember reading your post/name in post right after I installed my S/C, it never dawned on me.

A PM is enroute, just one question. Do I have to dimple the shaft for the three 10/32 machine screws?

BTW - I have your GI catalog, GI troubleshooting and set up guide in .pdf/MS Word formats. I was looking into your GI system as a later upgrade/mod.

AKS Racing

JS,
Quick Facts
- MIS is 62,000 for the P1SC
- L-98 drive pulleys are 7" (assuming factory pulley)
- P1SC step-up ratio is 4.10
- engine RPM should have approx 5% added to account for overspeed potential (5900 max RPM, so use 6200 for this example)
- driven pulley diameter will be 3.25" for the below example


The formula to use is:
[(drive pulley diameter*(22/7))*max engine RPM* step up ratio*(1/(driven pulley diameter*(22/7))] = impellor speed

This can be simplified to:
[(drive pulley diameter / driven pulley diameter) * max engine RPM * step-up ratio] = impellor speed

This equation yields a MIS of 54750 impellor speed at 6200RPM for a 3.25" driven shive, still over 13% from the top speed (even with the added 300RPM safety).

As an example, I am ~200 blower RPM over MIS at 6700 RPM, with a shift point of 6400RPM.

You have room to grow if that is your desire.

Aaron

jsavoy

AKS,
I really appreciate you taking the time to explain and providing additional information. I believe the LT1 stock crankshaft pulley size is 7" also.
John

yzfr1mike

I have a 3.4 inch pully on my kit and was told that was the smallest one they had for the p1sc. Smaller pulleys will slip more and probably won't be an advantage. But - - - ATI (the Harmonic balancer people) make a 7.5 inch balancer for the LT1, and it works great with less slip at the crank on the procharger kit.

Mike

BrianCunningham

Who built, and sold for a while, this custom COG setup?


One member overroad the tensioner spring, and used this instead

makn u shiver

i got this set up for mine ,its a system that replaces all the factory pulleys and runs a cog belt like stock.the only thing you have to do is make the tensioner adjustable and lockable .i was the one who paid the guy to design and build the first system and i think now 3 other forum members have bought it and a few where also built for some members c5 vettes to.he also makes any pulleys for any supercharger ,ribbed or cogged send me a pm if you want more info.btw who's car is in the first pic ?

Rokka

I got my cog pulleys from blackmountainprecision.com. Thanks for the Smokeshow for all the info and help!



As you see my setup is not ready yet. Some minor changes must be done. The belt is 2504mm long, 30mm wide, 8mm pitch.

AKS Racing

That belt is not 30MM wide. It looks more like a rubber band.

Looking good.

And yes Smokewhow (makin u shiver) did a great job in ironing out the details for the cogged drive with Black Mountain Presision. Mine was built by ASP Racing and was considerably more expensive than the package from Black Mountain Precision.

But on a word of caution, be aware that some of these cogged drives have done significant damage to the crank hub and or the transmission in the blower head unit. I no longer use the cog drive on mine.

Aaron