Like the title says. Are the pulleys the same? i need a 3.40" pully for my powerdyne..

-- Joe

 

Yes. FYI...928 Motorsports makes them in many sizes, number of ribs and colors. Carl also has the best rebuild and upgrade parts for powerdynes.

 

Its actually NO. Carl wouldn't make one bigger than 3.08 or something small, and vortech has a longer snout on the shaft. The powerdyne has a 3/4" shaft, so I had to cut the vortech pully down by almost a half inch in the lathe.

The diameter is the same, but the length is way longer on the vortech.

-- Joe

 

Was that suppose to be a trick question?

 

No. It was me asking, getting no answer, then buying two vortech pulleys and finding out for myself.

I dont understand why there isn't more powerdynes on here.
My vortechs whine used to make me batty, and the oil plumbing always leaked.

-- Joe

 

Sorry my bad I must be dyslexic because I thought you were asking if a powerdyne pulley could be used on a vortech supercharger. If so the answer would be yes because you just add a spacer. Just curious though unless you are reving the engine to 7000 rpm how do achieve any boost with a 3.4" pulley on a powerdyne?

 

7" crank pulley on a Corvette. 7" crank pulley + 3.48 supercharger pulley = around 38,000 RPM. Max efficiency is 40,000 RPM so figure it's right around peak operating range in terms of efficiency, figure 6psi boost. With a 3.33 pulley it would be around 8psi boost, and thats about the max on a BD11A.

You can buy a impeller from 928 motorsports for about $400 that will spank an S-trim, but with 10:1 compression I can't run more than 6psi anyhow.

-- Joe

 

Joe,

You could always get a March 5.75" crank pulley. I think this is the steel one #4101. There is also an aluminum version # 4111.

With my 2.93" blower pulley, I get 38,007 rpm at 6350 rpm. A 2.75" could work well also (38,263 @ 6000 rpm).

http://store.summitracing.com/egnsea...+115&y=13&x=35

 

Hey man,

Correct me if I'm wrong, but isn't it better to run a larger crank pulley and larger SC pulley, as you get more wrap around the pully (sc) so it won't slip?

I have both a 3.48 and a 3.33 now. The goal is to run the 3.48 initially, and go from there. Once I get some real runtime I'll know if I want to do the impeller swap and Intercooler.

-- Joe

 

I have one of Carl's billet impellers in mine and one of his vented impeller shafts with the best bearings he sells. The new impeller made the boost come in a little sooner and added about 1 psi on the top end over the stock cast impeller. I had to do some minor clearance work, with sand paper, on my discharge volute but it was well worth the time spent. I run an 8" crank pulley and I have three supercharger pulleys that I use on different occasions. My 2.9" pulley makes 7 psi of boost @ 6000 rpm, my 2.7" makes 9 psi and I have not run my 2.5" beyond 5000 rpm because I need bigger injectors but I would expect 11 psi. My CR is 9.7 so that would be going too far on my stock Vortec lower end anyhow.

Tom

 

Joe, you know what you're doing. No question, The larger pullies are preferred. I posted before I realized that you had already cut down a vortech pulley to work.

SSTahoe:

Its good to finally see some real feedback on Carl's impeller.

8" crank/2.93 blower and 6,000 rpm Wow!

That's 50,000 rpm at the impeller. Holy Smokes! I see that you have all the upgrades. How long has it held together under this configuration?

 

Thank you, I appreciate that

Yeah I had to cut a lot off the vortech pulleys, but the belt is dead aligned now. Carl wouldn't make me a 3.48 or 3.33 pully, biggest was like 3".. They must be running 4" crank pulleys on those Porches

I'm worried about over spinning the blower. I hear the vented mod helps though with keeping the bearings cool..

Only 1psi gain though? wtf..

All these air to water intercoolers I'm reading man say <1psi pressure drop.. I wonder if we could get away with nearly full advance with the intercooler on good old super unleaded... even if the thing put out only 6psi, if I could do it with 32-34 degrees of advance we're talking serious horsepower.


-- Joe

 

Actually it's a tick over 46k rpm but I don't usually rev it that hard. I have it set up to bring the boost in asap. It is unfortunately a 5000 lb Tahoe but it will definately surprise you. I have another vehicle for serious racing. The Hoe is a daily driver and occasional tow vehicle. I went with the billet impeller when my stock bearings wore out and let my stock cast impeller touch the volute and break a fin off. Carl's impeller was actually my cheapest option since Powerdyne is all but defunct as far as I can tell. Reading your posts made me think though. I'm surprise that I don't have belt slipage. At Least there is no indication of it. I'm building a new engine for it right now with a Holley Steath Ram, Comp Cams valve train & head work. Maybe I'll look into switching to pulleys that are more even than I have now.

 

I run an MSD 6 BTM with a **** inside the car that I can adjust timing retard from 0 to 4 degrees per lb of boost. It's really great to compensate for fuel quality and air temp. On the billet impeller, I was expecting more but as fast as I spin mine I need a light good balanced impeller. I would invest in chemical intercooling (h20 or methanol injection) before doing all the work of an air to water intercooler. My brother has one on his Charger with a Paxton/Novi supercharger. That sysytem has alot of plumbing for a tight engine area like in a vette.

You can see my set up at http://www.cardomain.com/ride/3047813 if you're interested. My supercharger pulley must look small compared to what you guys are using. It's good to know of other happy Powerdyne owners out there. Most people give me a hard time about mine because of their bad reputation in general but you guys know you can't beat how quiet it is and mine is reliable with all of Carl's trick parts in it. I've had 0 failures in about 25k miles.

 

Wait.. 8" crank pulley, 2.93" supercharger pulley, 6000 rpm on a BD11A with a step up ratio of 3.05 = 49,966 rpm... ??

http://members.cisdi.com/~anesthes/i...calculator.xls

-- Joe

 

Joe,

You're right and thanks for the calculator spreadsheet. Honestly I only ever push it to 6000 to see what the boost goes to. My engine combo peaks well below that right now so I usually shift it by 5500. With the upgraded parts Carl agreed that my Powerdyne should be able to flash as high as 50K - 60K very briefly. I will never be able to have my Tahoe run with something like your Corvette but I surprise some stock ones occasionally. I know it sounds like I'm full of $hit because who in their right mind would do these kinds of mods to a 5000+lb Tahoe but I tend to overdue everything I drive and I really like the uniqueness, if that's a word, of my vehicle. I can send photos of anything if you want to see. I had a Corvette and I really like them but I have a screwed up back and it's just too difficult for me to get in and out of them any more. I know it's lame of me but the pain really sucks!

Tom

 

I have not vented the case (yet). The impeller shaft I got from Carl is vented to help keep the belt from floating at high rpm. As for bearing cooling if I think it becomes that big of a problem I have an idea of how to move cool air through the front of a Powerdyne. Sorry but I'm saving that idea for now.

 

By chance does anyone know where I could get a stock pulley for a paxton sn92??

 

Hey Tom, I have a 95 Z28 LT1 Camaro, and i was looking to put some 2.5" pulleys on it, It already has a 6" Crank pulley. And about 6lbs of boost, But i want it to have more horsepower. So what i was wondering is, if i add a 2.5 lb pulley, how much HP will that get me? and if i need fuel injectors or anything else. What and what kind would i need? Thanks alot man!!

 

if u cant find a sc pulley, find a bigger crank pulley. it will make more boost. same effect as sc pulley. if cant find a sc pulley.
easiest way give it a hp kick as is now, is a meth injection kit.
60lb. injectors cost just a few more bux than 42lb. and have room to grow