NEW VR-4 KITS FOUND!!!!

[Cali]

....possibly

I've been in contact with a couple fab shops

928motorsports.com
and
supechargerrebuilds.com

Both fab high-boost impellers in-house for all the other designs.

They are both willing see if one of their aftermarket impellers can be modified to fit our SN cases and/or copy an existing design. But I have a few questions:

Does anybody have a VR-4 kit they're willing to send in to be copied?

Does anybody know if there's any copyrights on the VR-4 design?

I noticed the thin aluminum vein seperating the beginning of the volute from the end, is that the reason for a new back-plate vs. a spacer ring of some sort? (that qestion's from me, not them) Edit: nevermind, I see the intake is actually larger on the VR-4 kit also.

Since this is all trial-and-error, does anybody have any input on how much psi the stock housing could develop with a trick impeller? I ask this simply because it would be cheaper and easier if we could just drop-in a state-of-the-art impeller and skip the housing change.

And how many people are still interested in picking up something? I'm sure a posting on ebay would develop a new following for this old horse- but some commitment might get a better price/faster return rate for starters.

What are people willing to pay for a new, untried design?

[Cali]

I'm willing to be the guinea pig and see what a modded impeller with the stock case is capable of. One of the vendors is only about 2 hours away from me.

[Michael]

Craig Conley of Paradise Wheels might take issue with something like "copying" a VR-4, as his company own the copyright (drawings, tooling, parts/spares, etc...) to all the old ball-drive Paxton superchargers, including the SN series of blowers as well as the VR-4.

I believe designing/developing a new impeller would lie outside the realm of copyright infringement, and would certainly be very welcome by many an SN owner, but it wouldn't be cheap even for a company with extensive experience in modern turbine design. The return on investment would be questionable at best.

Have you tried contacting Craig to see about getting your hands on a VR4 kit? I know there was a group buy being run by him not too long ago, but SCH isn't affiliated with Paradise Wheels so I don't know how close to the required number of buyers he is, or if this ever materialized at all. There's an announcement at the top of the SN Series section with all the details and Craig's contact information.


Oh, and I should also mention... I believe Mr. Conley is a member of this site, so openly discussing "copying" something he owns the rights to might not be a good idea.

[pavement pounde]

Besides a better improved impeller you must open up the rearplate to make more boost.

[Cali]

Craig Conley of Paradise Wheels might take issue with something like "copying" a VR-4, as his company own the copyright (drawings, tooling, parts/spares, etc...) to all the old ball-drive Paxton superchargers, including the SN series of blowers as well as the VR-4..........

Have you tried contacting Craig to see about getting your hands on a VR4 kit? I know there was a group buy being run by him not too long ago............

.

I was hoping someone would say one way or the other on the copyrights- I don't want to get into a project and have it shelved for legal purposes.

From what I read of the thread on the VR-4 kits, PW did up 30 and decided it was too much of a hassle to make another run.

And honesty, I'd like to have some type of future for the SN- if I can't find replacement parts in the future, then a single VR-4 kit has no value to me.




If the stock/HO impellers run 5- 7-ish psi, with the VR's making 14+, who would be happy with something inbetween, maybe 10-ish if it was just an impeller swap?

[Michael]

I was hoping someone would say one way or the other on the copyrights- I don't want to get into a project and have it shelved for legal purposes.

I can't comment one way or the other whether a project like this would get tied up in legal/copyright issues. It would obviously depend on whether Paradise Wheels (ie. Craig) was willing to put the necessary resources into pursuing legal action. And given that the 'supercharging' business isn't big (ie. not many players) I don't want to speculate if there's an existing relationship between PW and the people you've been speaking with.

Personally, if I were looking for a VR-4 kit, I'd avoid the potential issue and just go straight to the source: Paradise Wheels.

From what I read of the thread on the VR-4 kits, PW did up 30 and decided it was too much of a hassle to make another run.

And honesty, I'd like to have some type of future for the SN- if I can't find replacement parts in the future, then a single VR-4 kit has no value to me.

The 30 or so VR-4 kits you're referring to weren't put together and sold by Paradise Wheels, they were put together by Solanski Performance. Solanski have been in the Paxton Supercharger refurbishing/restoring business for years (they specialize in the restoration of old Studebakers), so my guess is they had a VR-4 in their shop which they used to replicate and make the VR-4 kits. This is not unlike what you're trying to do, but given that they've been in the business for a long time, I don't know what kind of relationship they have with Paradise Wheels such that Craig turned a blind eye to this. Who knows... maybe Craig even supplied them some of the parts...?

And I wouldn't worry so much about not finding replacement parts. Most of the parts used in the VR-4 kit are identical to what you'll find in an SN. The parts which are truly different are the rear scroll and the impeller, and these very rarely have to be replaced.

If the stock/HO impellers run 5- 7-ish psi, with the VR's making 14+, who would be happy with something inbetween, maybe 10-ish if it was just an impeller swap?

Your logic certainly can't be faulted. I think a lot of SN owners would love to get their hands on a more efficient impeller that would produce between 9psi-11psi without the need for a new scroll or spinning the blower any faster. But, as Marco (pavement pounde) suggested, making this kind of added boost would probably require more than just a simple impeller change, leading to a redesigned (larger) rear scroll. Big money, from the stand of points of both development and final cost to the buyer.

Besides, getting 10psi of boost from a VR-4 isn't difficult. Just spin it at a lower RPM. Just because it can produce 14+psi, doesn't mean you have to spin it up that high.

[Cali]

Ahhh, I love feedback.

My bad on the 30 piece run. The vibe I've gotten from all of the posts I've read on the VR's is that they're next to impossible to get ahold of- that run seemed like a last-ditch effort that alot of people were hoping for.

I'm really looking for an alternative to the VR's. They have great potential in and of themselves it seems- totally streetable and yet can still hang with the big dogs at the track. But they might be a little much for alot of applications (cost, effort and psi). By the time you purchase an SN, rebuild it, slap on a VR kit, you might as well have bought a Novi 2000. Although the backplate and impeller should last a lifetime, it seems as though one bad day at the track or on the workbench and everything you've built your system around is going to sit in a milk crate in the garage until you get lucky enough to come across a replacement part---------- and I like to break stuff.

I'm fairly sure that just a custom impeller made with modern technology (and a big slug of billet) would escape any copyright issues. Should be more effecient and better balanced than the cast pieces too. Although I'm not a design engineer, I've dealt with enough turbos and supers to find it hard to believe that the SN's case is maxed out at 7 pounds.

[Joo]

I thought about an improved impeller design too. You have to consider, that the ball drive is designed for a maximum of approximately 40.000rpm. Most modern impellers are rated at 55 to 70.000 rpm. To use those impellers in an SN would be not an good idea in my opinion, because it would probably reduce the efficiency of the impellers (bad thermal efficiency and high termperatures).
I have found only a few impellers that are rated at 40.000 rpm:
Paxton Novi-1000 and 1000RR, max 15 psi, max airflow 850 cfm, inlet 2.9", outlet 2.6"
and
Powerdyne BD-600 and BD11A, max 13 psi, max flow 900 cfm, inlet 3.5" and outlet 2.75"

The outlet of a SN is 2.5", the inlet 2.5". That's the main problem and why the VR4 has a special scroll cover.

Joo

[Cali]

Ummm- my GSS isn't 2.5x2.5 (?) I don't have it with me, but it's more like 2.75x2.5, wich is pretty close to that 15 psi/850 cfm casing you posted.

I'm not expecting 15 psi.

And I wasn't thinking of just cutting down a novi impeller for a SN. Modern concepts could be used to design a more aggressive impeller for the lower RPM's that these spin,

The cast impeller has alot of wasted mass that could be trimmed down and used for moving air in a stronger billet application. Not to mention this is still 50 year old technology, at best even the VR is pushin' 20 years.

I drive a HEMTT that never sees 3,000 rpm's, yet it's turbo impeller has enough force to suck in a small child. I know this is apples and oranges- and an impeller that rocks in my application may suck (hey look a pun) for someone trying to build power higher up in the rpm band, but it's hard for me to believe that this SN is maxed in it's stock form.

I've got a couple bucks just sittin' around, so I'll do the dirty and be the one to try this out.

[winfred]

one step further then the upgrade impeller is all thats desired, the stock blades are almost curved, the upgraded has a little cup to it, make one with some scoop to em

[Michael]

Ummm- my GSS isn't 2.5x2.5 (?) I don't have it with me, but it's more like 2.75x2.5, wich is pretty close to that 15 psi/850 cfm casing you posted.

After reading Joo's post, I was a bit skeptical of the inlet/outlet diameters too. I just measured the inlet/outlet diameters of my SN89, and I have admit - Joo's numbers are right!

The inlet opening on my SN89 measures (as near as makes no difference) 2.575" and the outlet measures 2.500" exactly. I honestly thought it would be a much bigger difference between the inlet port versus the outlet port. A GSS' inlet/outlet ports may be different though.

But hats off to Joo.

The cast impeller has a lot of wasted mass that could be trimmed down and used for moving air in a stronger billet application. Not to mention this is still 50 year old technology, at best even the VR is pushin' 20 years.

I drive a HEMTT that never sees 3,000 rpm's, yet it's turbo impeller has enough force to suck in a small child. I know this is apples and oranges - and an impeller that rocks in my application may suck (hey look a pun) for someone trying to build power higher up in the rpm band, but it's hard for me to believe that this SN is maxed in it's stock form.

I've got a couple bucks just sittin' around, so I'll do the dirty and be the one to try this out.

I think you've touched something very important here. The technology behind these old ball-drive chargers is old, but it's not only in the design of the impeller that's limiting their performance... it's also the design of the scroll/housing as well. Both work in conjunction with one another, so redesigning the impeller without doing the same to the scroll might lead to a slight gain in boost or flow, but it probably won't be much in comparison to what you'll spend in development costs. I'm not talking about the size of inlet diameter... I mean the internal contour/shape of the housing and it's relationship to the impeller's blades. Once you start talking about redesigning the scroll AND the impeller, you're potentially getting into some big investment dollars.

However, I do agree with you when said that the cast impellers have a lot of mass. Not to mention, they're not easy to balance, and their overall strength isn't anywhere near what you'd get from a billet unit.

I think if you're serious about doing this, a great place to start would be to get your hands on just a VR-4 impeller (easier said than done, I know), and replicate it in CAD. We know the VR-4 is the best impeller for the speeds these old ball-drives spin at so why mess around trying to develop a better design? Once the impeller is in digital format, it can be easily manipulated/modified to make it fit an existing SN scroll. From that point, finding a shop that can machine one out of billet aluminum isn't difficult. The material costs won't be too bad either - what are we talking about, a billet of aluminum that's approximately 6"x6"x2.5"... maybe 7"x7"x3"? That's not very big... maybe $150 worth of material? Even if it's $200... that's peanuts. Where you'll spend the big money is in the machining time. Even if a shop were to use high-speed machining, it would probably take the better part of a day to machine an impeller (depending on complexity/undercuts/etc..). I don't know what the going rate for a good machine shop is today, but I'd guess it's close to $100/hr, which means you're going to be in for at least $1000 in machining time alone (could always go to China to have it done, but let's not get into that)... and that's assuming the shop just has to hit the "go" button on the machine... if they have to start messing with the CAD data in order to actually make the part... well, then the cash register sound just gets louder.

But this isn't impossible to do. Heck, I'll even do the CAD work if someone is willing to send me a VR-4 impeller so that I can replicate it! And I know a few people in the "machining" business... I could make a few phone calls to find out how much material would cost and what machining costs would be like.

The only question is how much gain (if any) would a scaled-down VR-4 impeller provide?

[Cali]

I'm real curious now exactly how large my intake is... I swear it looks bigger than that!!!

I have a quote for $425 for an experimental billet impeller.


The casing is probably the biggest issue to make an SN perform like a newer unit, obviously it's a bottleneck or the VR wouldn't have a new backplate. I myself (and many others) would probably just be happy with a slight increase in performance, not full-out VR specs.

Having a foundry cast a new piece is way more effort than a CNC mill squeezing out a new impeller. What about putting our existing backplates on the router table and chewing out a little bit bigger of a passage? It would narrow the supply chain portion of this issue. Anybody have any figures on how much bigger the VR's backplate portion of the volute is over a stocker? Not sure if there's enough material in the SN's housing to do it, but it might be another option. A "spacer ring", with the small aluminum vein seperating the beginning/end of the valute welded in might be another option (I couldn't see just a bolt-in spacer working with that small sliver, but 2 minutes of welding and 5 of grinding might work out).

[Michael]

I'm real curious now exactly how large my intake is... I swear it looks bigger than that!!!

I thought the same thing! LOL!!! That's why I went and measured mine... I couldn't believe the inlet and outlet were the same size.

But the Vernier doesn't lie.

I have a quote for $425 for an experimental billet impeller.

REALLY?!? That's a steal! But is that for just the machining work? Does that include the material too? That price can't include any CAD work...?

The casing is probably the biggest issue to make an SN perform like a newer unit, obviously it's a bottleneck or the VR wouldn't have a new backplate. I myself (and many others) would probably just be happy with a slight increase in performance, not full-out VR specs.

It's both the impeller and casing. A large/redesigned casing would facilitate a redesigned impeller; a new impeller would (probably) required a larger/redesigned casing. They aren't mutually exclusive... unfortunately.

Having a foundry cast a new piece is way more effort than a CNC mill squeezing out a new impeller. What about putting our existing backplates on the router table and chewing out a little bit bigger of a passage? It would narrow the supply chain portion of this issue. Anybody have any figures on how much bigger the VR's backplate portion of the volute is over a stocker? Not sure if there's enough material in the SN's housing to do it, but it might be another option. A "spacer ring", with the small aluminum vein seperating the beginning/end of the valute welded in might be another option (I couldn't see just a bolt-in spacer working with that small sliver, but 2 minutes of welding and 5 of grinding might work out).

If you're talking about making thousands of parts (which is what I'm sure happened when these impellers were first designed/manufactured) casting was (and still is) the most cost-effective option. Even with the ease of NC machining, because of labour, tooling costs, maintenance, etc... casting is still cheaper when the volume is very high.

As for the VR-4 vs. an SN, you're best bet is to search around the site here for photos. I'm sure someone has posted some. I know Buck-Strickland recently got his hands on a VR-4 - maybe he's posted some photos? But I know the difference is fairly significant.

[Cali]

REALLY?!? That's a steal! But is that for just the machining work? Does that include the material too? That price can't include any CAD work...?

That's to adapt an aftermarket impeller design (wichever one of his styles that's closest to the SN's as far as case/impeller size)

If you're talking about making thousands of parts (which is what I'm sure happened when these impellers were first designed/manufactured) casting was (and still is) the most cost-effective option. Even with the ease of NC machining, because of labour, tooling costs, maintenance, etc... casting is still cheaper when the volume is very high.

I ran a CNC router for many years. I could squeeze out some beautiful and intricate stuff from a 1" plate of aluminum by the end of the day, but it would take ALL day!!! I don't want to think of how much time it takes to cut an impeller, or especially a backplate.


It doesn't seem like the market is big enough for a full-on mass production (or I'd think it would have been done) the last 30 piece run seems to verify that- fully CNC'd parts may be the only option for the occassional customer wanting an upgrade.


So on to the fun stuff----------------------

"My" fab guy has an SN-89 in his hands and is moving forward on an impeller-only upgrade.

He's still interested in getting his hands on a VR-4 for calibration purposes to compare case volume/ impeller dynamics. If anybody has one they'd be willing to share for a short time, PLEASE raise your hand. If only long enough for Michael to get AutoCAD time with it, it may be highly beneficial to all of us (and thanks for throwing your hat in the ring and offering that up Michael).

I'll keep updating progress as this moves forward. My 347 SBF "test platform" should be back in one piece this weekend.

[Michael]

If anybody has one they'd be willing to share for a short time, PLEASE raise your hand. If only long enough for Michael to get AutoCAD time with it, it may be highly beneficial to all of us (and thanks for throwing your hat in the ring and offering that up Michael).

A friend of mine works for an engineering/design company that's just purchased a 3D scanner. I just checked with him and he said it'd be fine for me to use it.

That would cut the amount of time I'd need a "donor" VR-4 impeller to a day or two; I would ship the impeller back to it's rightful owner as soon as I was finished scanning. Hell, I'll even cover the shipping charges both ways if that'll help get some interest.