Hi,
I recently became the owner of an Audi B8 s4 and absolutely love the Eaton TVS Charger on it. I recently tried a port and polish of the supercharger myself, in hopes of improving performance and saving money. I thought I did good for a first time, but after reading more and more I think I might have damaged my supercharger rotor "timing" but messing up the ports and creating a smooth tapered inlet. I thought I wasn't doing damage by opening the inlet as large as possible but maybe I did? Please educate me, even if theoretically, what did I change? I thought bigger inlet= more air for thirsty charger but I guess not so from the consensus on chargers. But from the Eaton patent I was reading,

"As the [supercharger] ports were widened to provide increased flow area needed at high speeds, seal time and efficiency decreased."

Did I improve the flow of my supercharger, but hinder its efficiencey?
Attached are photos of my rotor inlet for the charger and other porting. Stock pictures of the charger show a much smaller and sharper inlet shape, which I thought was bad for heat. Sharp corners= friction/heat. Please let me know, I have some other porting ideas which I thought would give me more power but I am holding off as I think my understand of this roots blower is not as good as I thought. Thanks for your time. #ad
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Hello! Thank you for the reply!

I modified both, but inlet more so than outlet. The outlet “V” had a thick lip or like a step so I sanded that down to create a thin edge in attempt to improve exit flow. It was hard to see and capture in photos but if you look close you can see the edge for the V exit leads straight into the cavity above the rotors. It was a lot of sanding!

 

I have seen a bunch of Audi guys dyno and provide good results which beg to differ with your statement, but that’s not the point here. I’m inquiring about how I can get that 15 hp improvement. I have seen the gen3r guys open up the inlet of their blower almost 270 degrees around the shaft of the rotor. So I wonder if there is any sort of “tuning”, because on those blowers a larger inlet provides no negatives.

 

How do the dyno runs before and after your work compare?

 

i know this is an older thread - but i am interested in this TVS unit for a project i am working on - i have a few questions :

1. does anyone have images of the stock inlet and outlet areas - to compare to the ported photos above
2. can anyone point me to images or info on how deep the plenum above the exit port is ( the area where the air turns before going into the intercoolers ) its the cross section i am interested in - if the unit is sliced trough the centre line between the rotors - front to back
3. does anyone know what direction of rotation this Audi TVS uses - it looks like its counter clockwise when viewed from the pulley end - can anyone confirm