SN History

[jlmccuan]

Can anyone give the history of development of the SN's from the 60 on up? Something that would explain the advantages and disadvantages of the SN93 over the SN89 and the like. This is sticky material.

[speedytang]

Search on Google and you will find the information or Buy the book by Granatelli that explains the family history of Paxton and McCulloch Supercharger.
Example:
http://www.vs57.com/

[Scribbles]

the link does not work

[JPJP]

The link is the correct link. The site must be having problems.

[jlmccuan]

Still haven't found a definitive list of changes from model to model. Does one exist?

[Michael]

Still haven't found a definitive list of changes from model to model. Does one exist?

I haven't seen a definitive list of changes from model to model for the SN, and to be honest, I think that list would be very short indeed. The SN series of superchargers are all virtually identical, with very very minor changes between them (save for the VR4, which had a distinctly different rear scroll and impeller).

However, I have posted a four-part history of Paxton/McCulloch superchargers which may provide you some answers. Most of the information is from www.vs57.com, but seeing as the site has been down for the last while I figured it would be beneficial to post the information here. All four parts are "stickies" at the top of the SN Series forum, but I've included the links below:

Paxton-McCulloch Supercharger History - Part I

Paxton-McCulloch Supercharger History - Part II

Paxton-McCulloch Supercharger History - Part III

Paxton-McCulloch Supercharger History - Part IV

Enjoy.

[Scribbles]

thanks :)

[jlmccuan]

Great background. Thanks

[suede57ford]

Thanks for taking the time to post the McCulloch/Paxton History. Great job.

I am a fan of the VR57 Blowers as I have one on my '57 Ford sedan with a 312 Y-block. It has run 12.90's in full street form and is driven all the time on the street and multiple Hot Rod magazine Power Tours (Hot Rod mag, Nov 08, page 41).

I have been converting the VR57 blowers to us the SN93 internals so that the F-code Fords and Thunderbirds can have a reliable and now rebuildable unit. The blowers still look factory stock on the outside, but perform like the reliable SN units. I have produced 8 psi on my car with the high efficency impeller.

I have already converted 20+ original VR57 blowers for other F- code '57 Fords an T-Birds.

I am working on a race VR57 that is going to use a VR4 impeller for my race motor. I expect 12-15 lbs.

Thanks for sharing info on the site, very usefull so not everyone has to reinvent the wheel,

Pat Fleischman
Lubbock, TX

[Granatelli]

I haven't seen a definitive list of changes from model to model for the SN, and to be honest, I think that list would be very short indeed. The SN series of superchargers are all virtually identical, with very very minor changes between them (save for the VR4, which had a distinctly different rear scroll and impeller).

However, I have posted a four-part history of Paxton/McCulloch superchargers which may provide you some answers. Most of the information is from www.vs57.com, but seeing as the site has been down for the last while I figured it would be beneficial to post the information here. All four parts are "stickies" at the top of the SN Series forum, but I've included the links below:

Paxton-McCulloch Supercharger History - Part I

Paxton-McCulloch Supercharger History - Part II

Paxton-McCulloch Supercharger History - Part III

Paxton-McCulloch Supercharger History - Part IV

Enjoy.

I am not sure who wrote all this but most of it is slanted and not much of it is accurate from 1979 on.

If anyone needs help or history on the Paxton Ball drive or Gear drive - perhaps I can help

Joe Granatelli

Vice President of Paxton Superchargers and Fuel Systems 1991-1998. My father was Joe Granatelli Sr. the eldest of the 3 brothers. Andy as an example had no ownership in Paxton after 1974. We never stopped making supercharger kits and systems but yes in 1979 when the people were no longer hyperfocussing on the gas crunch it became popular again.

naturally I could go on but I won't

[SuperL98]

I am not sure who wrote all this but most of it is slanted and not much of it is accurate from 1979 on.

If anyone needs help or history on the Paxton Ball drive or Gear drive - perhaps I can help

Joe Granatelli

Vice President of Paxton Superchargers and Fuel Systems 1991-1998. My father was Joe Granatelli Sr. the eldest of the 3 brothers. Andy as an example had no ownership in Paxton after 1974. We never stopped making supercharger kits and systems but yes in 1979 when the people were no longer hyperfocussing on the gas crunch it became popular again.

naturally I could go on but I won't

Joe,
It’s nice to have someone closely involved with the early Paxton’s drop in here:)
One question that we have never seen answered is, had anyone ever done compressor maps for the SN series or VR4 superchargers?
If so, you wouldn’t happen to still have them available.
Even knowing the Island values (CFM, Pressure Ratio, Efficiency, RPM) would fill in a big hole in the history, and help us size these better to applications.

All that anyone has found was for the old McCulloch VS57

http://i237.photobucket.com/albums/ff47/SuperL98new/VS57.jpg

Some of us are still faithful to these old Paxtons ;)

[Granatelli]

Joe,
It’s nice to have someone closely involved with the early Paxton’s drop in here:)
One question that we have never seen answered is, had anyone ever done compressor maps for the SN series or VR4 superchargers?
If so, you wouldn’t happen to still have them available.
Even knowing the Island values (CFM, Pressure Ratio, Efficiency, RPM) would fill in a big hole in the history, and help us size these better to applications.

All that anyone has found was for the old McCulloch VS57

http://i237.photobucket.com/albums/ff47/SuperL98new/VS57.jpg

Some of us are still faithful to these old Paxtons ;)

:)That pic above was created by John Thompson even before I was born (i think)
:happy:

Keep in mind those number are conservative and that unit was sized for a Kaiser and the 312.

I will get out my old books and see what I can find - I am sure I have tons of flow data. The VR4 will be hard to find - we kept those numbers under our hat and never showed the numbers because it was considered a race blower. Hence when I sold my portion of the business the new guys got all that data and they were not smart enough to know what they were looking at. - Most of it got discarded

[SuperL98]

It's interesting how the data points for the VR4 (Psi vs Cfm) that you gave in another post, look layed on top of the Novi 2000 chart.



Wonder which VR4 impeller these numbers are for?

[444]

Joe, great to hear from you! Detailed SN info seems to be such a tightly guarded secret that it leaves a lot of us scratching our heads wondering where to start. Any additional detailed info you have the the SN series blowers and/or the SN w/ HO impellor units would be absoloutely awesome.:)

[Granatelli]

It's interesting how the data points for the VR4 (Psi vs Cfm) that you gave in another post, look layed on top of the Novi 2000 chart.



Wonder which VR4 impeller these numbers are for?

That stuff looks like great PR and media mumbo jumbo.:freaks:.
I would not give much credit to anything that came out of Paxton Automotive from 1999 to 2003. The company was terribly mis managed. The Billet VR4 Impeller (top left) is not real - as in Paxton never shipped impellers like that. Also note the flat disk design depicted in the billet VR4 picture would have increase flow and killed pressure. The cast version (top right) which is what we actually sold would loose a small amount of flow down low but make a ton more at the top - both flow and pressure