The only way to quiet down the supercharger unit is to raise the idle to about 800-900.The unit will still have a slight whine though.To me the Stillen kit is very quiet compared other kits using the same vortech unit that vent to atmosphere.

I saw one guy here installed Stillen kit on a 5AT G37 coupe and tuned it via unichip i think he was pushing around 430-430whp on dynojet.

RCZ is right. I have no complaints from my kit and my review speaks for itself. I just wish I lived closer to sea level! I am hoping to be able to replace my 9PSI pulley and get up to 8 PSI of boost at altitude. I am currently trying to determine what RPM the blower is turning with the 9PSI pulley to see how close I am to the 52K upper limit. That 928 motorsports impeller also looks promising but would cost a bit more than a pulley swap.

There is no way for you to know how close your are to the limit of the unit without having cog pulleys.In order to find out how fast you are spinning the blower you have to put in the crank pulley size plus the supercharger cog pulley and jack shaft cog pulley ,and use the impeller speed calculator on Vortech web site..This is the one of the reason's I made the switch to a cog set up.With the 928 motorsports impeller you can spin to 60k up from 53k.

Even with doing all of that there is still some belt slippage that you can not account for from the serpentine belt on the front.

Drag slicks? I imagine those would help cut that 60' time down to 1.6 or so, which would help the overall E/T. Making that power the car should be in 11's for sure.

I was told the V3 is good for 18psi on an otherwise stock z... I could be totally wrong with this guesstimate, but I guess its only an approximation. Assuming that you will lose a few psi with other high flowing supporting mods...lets call that 15-16psi on a VQ37...would it be fair to say that that is our ceiling for power on this supercharger?

The stock block is probably good for ~11PSI at the limit...

Not only does the 928 impeller produce more power at the same impeller speed...but it also has a higher ceiling as Mr. Squeeze described. I don't know if the top RPM of the SC is limited strictly by the impeller or not, but all in all, this SC + the 928 Motorsports impeller has the potential to go well into the 500whp range with some internals. Hell, it can probably be enough to push those upgraded internals to the limit too.

The other advantage is that you can get the same power with less wear and tear on the SC unit since it will be spinning slower than the stock impeller would be.

Thats all true and the 928 Impeller is definitely a must to max ot the V3 but I am only wanting to get to a full 8PSI at altitude and use the 928 BLV set to 8 PSI to ensure that I stay at no more than 8 PSI even if I take the car to lower altitudes. I don't want to amp it up to the point that I worry about trashing the AT. Now if I had the MT, I would be tempted to explore the 10 PSI range but then you start getting into worrying about the engine internals.

BTW RCZ, the Vortech site lists the specs on the V3 in our kit as 53K RPM and 17 PSI max boost. Here is the link to their specs page:

V-3 SCi-Trim Supercharger | Vortech Superchargers

A quick, rough calculation gets you approximately 3117 RPM per PSI based on the 53k/17PSI max numbers. So that means the 9 PSI pulley should be turning somewhere around 28,058 RPM if you assume 100% efficiency. If you roughly factor in their peak efficiency of 75% listed in their specs then it should be turning around 35,073 RPM. Either way, there should still be a lot of headroom left and you get even more headroom using the 928 impeller.

By the way Mr. Squeeze, nice job on your build! Do you still have the slotted pulley off the SC itself? If so, could you measure it for me? I don't want to take the belt off mine just to make a measurement.

I don't know if I will actually make any changes as the car drives great and has good power but it is alwasys fun to explore the options.

the impeller is a good choice as it should only make another 1psi more peak for you but would increase boost slightly throughout the rev range. You can get the impeller off ebay from 928 for about $30 cheaper then the website.

The vortech sc bearings are ABEC 7 and are rated up to 59k

dal1307 I do not have the pulley anymore I damage it taking it off.Those pulleys had loctite,and was a pain to remove.

No Problem, I will just have to take off the belt and measure it, just being lazy :tup:

Hey Mr.Squeeze you seem to know alot about the supercharger. Im currently at 390whp.
1.) how much more power can we get with a 9 psi pulley?
2.) My auto guy said changing to stillen cats with another tune, we might get 30 or even 40whp?

thanks man!

Wow, its got a nice set of bearing in there.

What type of dyno did you get the 390WHP on was is a dyno jet?

If I had to take a guess I would say about 30 or so, I am not a 100% sure because I haven't used the pulley my self yet. My numbers are without using that pulley.

I also have never ran cats on any of my supercharger set up's I alway use test pipes.

i used mustang dyno. wow the difference in our power is very big though hahaha

geoharto, I only made 400whp on a mustangdyne. Then I went to a dynojet and made 455whp.