NoviGSS questions

[Corvette91]

Hi all!

I have a 91 Corvette with a NoviGSS. I've read some of the posts here but am a little confused.

1) I read that the max impeller speed is 38000 rpm. I've also read that it could take 45000 rpm. Or is it the older ones that could take 38000 and the GSS and Sn2000 45000?

2) In the "history lession" post, I found: "the company upgraded the design of the ball drive supercharger and changed the name from the NOVI GSS to the SN 2000 in an effort to avoid any marketing confusion with the NOVI line." But I also read that the NoviGSS and Sn2000 are the same, which is it? Wouldn't upgraded ball drive design allow for higher max impeller speed?

3) Is the max flow 850 cfm for the NoviGSS and Sn2000? I've seen some other number too.

4) I read that all the Sn blowers have step up ratio 4.44:1 but I also read that the GSS has 4.40:1. So the GSS has 4.40 and the Sn2000 4.44:1? Or could it be that 4.40 is a typo?

5) The GSS is a centrifugal blower, does this mean that for a given impeller speed it will start to build boost? Eg, my crank pulley is 183 mm and the "stock" sc pulley 108 mm. At about 2500 rpm engine speed it starts to build boost, this is about 18808 rpm impeller speed. If I change the sc pulley will it always start to build boost at 18808 rpm impeller speed (but the engine speed will change)?

6) If I rev the engine to 6000 rpm the boost level is about 7psi. If I've done the maths correct that would be 45140 rpm impeller speed. Is 7 psi a normal number for this impeller speed? Is it safe to rev this high?

7) The improved impeller (1.5 psi) available eg at Paradise wheels, will it start to build boost at lower rpm or only build more boost at higher rpm than the stock unit?

Sorry if some of the questions are stupid but I want to learn :)

Rob

[pavement pounde]

1) with the new design 3 lip rear seal what you should have you can go 45K max but if doing this for long times on the intersate I would sugest a oilcooler.
2) The internals are all the same exept for that regular or 3 lip rear seal, the housings somewhat differs from design.
3) I beliefe so.
4) All ball drives have 4.44:1
5) I don't know actualy, mine at first with the SN93 and now with the VR4 it always made inmediatly boost when hammer the trottle at any rpm.
6) If running 45140 rpm impeller speed be sure to use a oilcooler anyway.
7) If I am not mistaken you allready have the improofed impeller but can easely scheked at the rear side of blower if the blades are curved.
Check this (blurry) picture I took, the one instald on the left is the improofed one:

http://img.photobucket.com/albums/v1...d/Pic_0019.jpg

[Corvette91]

1) Some small amount of oil is leaking through my blower (even at impeller speed << 45000), would the likely cause of this be the rear seal?

7) Mine does not have the red/pink colour, would that imply I have the "low" boost impeller? The one on the right, are the blades convex on one side and flat on the other? The pink one seems convex on one side and concave on the other, is this observation corrrect? Mine seems concave... I'm a little lost, perhaps I'm looking at wrong features?

8) I plant to rebuild the unit this winter. Should I just replace the rear seal or buy a complete rebuild kit at eg Paradise wheels? At the same time I'll add an oil cooler. The one offered by Paradise wheels seems to be nice price, is that a complete kit och just the dip stick? If I manage to figure out which impeller I have I might also buy an upgraded impeller.

Thanks for you reply, Rob

[pavement pounde]

1) Yes you need a new 3 lip rearseal.
7) Don't look at colors, 1 is used and the other new/clean, just zoom in and notice the differense of shape, yes your right those are the differenses.
8) It is dificult to tell what to do, but if there are no funny noises and no phisical signs of wear and the turning of the pulley goes smooth then I would do only the rearseal.

[Corvette91]

7) OK, I already have the improved impeller. Very good, don't want to waste money buying an identical impeller.

8) I've had it for four years and never had any problems with it. Very silent and will give me reliable 7 psi boost. I'll disassemble it and do some inspection, if I don't see any faults in it I just replace the rear seal. I'll do the "complete" rebuild later then.

Thanks Rob :)

[pavement pounde]

I also have the Paradise oilcoolerkit, it is complete with a large radiator for good cooling affects, I only shanged the filter for a clear one so you can see the color and flow of the oil and "hopefully" no debris.

[Corvette91]

Great! The clear filter was a really good idea, I'll do the same on my.

Rob