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      10-25-2012, 06:22 AM   #68
pokeybritches
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Drives: ESS/G-Power Z4M, VF Z4, 996tt
Join Date: Sep 2009
Location: Los Angeles

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2006 BMW Z4M  [10.00]
2006 BMW Z4M  [8.50]
2003 BMW Z4 3.0i  [9.00]
What? lol... I think your dyno is for an M54, not an S54. The M54 redlines at 7k rpm with most aftermarket centrifugal setups, and the S54 at 8k rpm. The S54 also produces a lot more than 261 whp on boost. Those aren't even stock numbers.

AA E46 M3 dyno:



VF Engineering:



Rotrex technical data (C38-81 used on the E46 M3): http://www.rotrex.com/Home/Technolog...ical_Data.aspx

There is no way "some guy" is pushing 350 lb-ft @ 2k rpm with a centri blower, or even pushing high boost at that rpm with a centri blower, period. It is not physically possible based on the way the blower develops boost. Either someone lied to him, or he's lying to you. If Rotrex centri blowers somehow magically made power down low, why would AA have ever pursued a twin screw design on the E46 non-M? Why do they use HKS blowers on the M3 now?

Regardless of what is said, all of the centrifugal superchargers are very similar. All of this crapping on Vortech is kinda getting annoying. The dyno graph OF ANY CENTRIFUGAL SUPERCHARGER on this engine will look similar to ESS's, regardless of what blower is used - peak power coming in at redline, virtually no change down low. That's why people go with turbochargers or twin screw setups. Sure, you can size things differently and limit your ceiling, gaining a little bit by keeping the blower in the ideal range where it's most efficient... at the end of the day, the car develops boost based on rpm. G-Power even offers an optional clutch that disconnects the blower at 1500 rpm, because it's not necessary at those speeds.

Never compare one manufacturer's claims to another. I doubt there's a drastic difference between the G-Power and VF480 setup. I accept that the G-Power blower is more appropriately sized to the kit, and that may make some difference, especially in the midrange. At the end of the day, they both generate power the same way using identical boost. Neither will generate absurd torque down low.

On a different note, Technique Tuning announced an E46 M3 turbo kit using the stock DME. Expected price is $9500 with race cats, which is a steal when you factor in the other things a turbo setup lets you avoid - specifically, aftermarket headers. FYI NickG is arguably the best BMW tuner out there. He is the only person to successfully develop and market an E46 non-M turbo kit that runs on the stock DME, and his kits get rave reviews. Now if they would just develop this for the Z4M...
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VF Engineering Z4 3.0i, ESS Z4M, G-Power Z4M, 996 Turbo

Last edited by pokeybritches; 10-25-2012 at 06:32 AM..
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