Just got back from the dyno!! Stage 5 AMS + Zero Clearance results inside
#121
ok...i didnt know what jeff was referring to
but if the compressor wheel is doing more work at a higher efficiency, isnt it going to be doing less work overall because it is more efficient? that is a possible explanation for the lower initial torque curve, however i think tuning needs to be worked on that will improve that
#124
AudiWorld Super User
yeah, i think we both need to hire RocketBoy as our technical writer.
<ul><li><a href="https://forums.audiworld.com/s4/msgs/1606238.phtml">https://forums.audiworld.com/s4/msgs/1606238.phtml</a></li></ul>
#128
Our car is a freak.
Our dyno reads very similar to GIAC's (we spent time calibrating both to make our lives easier).
On the latest test code, two other local cars see ~370whp with same hardware as on our car.
Knock voltages on our car are not that high either, and were a tad higher on the other cars.
Just goes to show the variances you can see among these cars when pushing the envelope, and why tuning them is so freaking hard.
Keep the power to chipped K03 levels and cars are a lot more even in output, most likely since the hardware is getting maxxed out.
On the latest test code, two other local cars see ~370whp with same hardware as on our car.
Knock voltages on our car are not that high either, and were a tad higher on the other cars.
Just goes to show the variances you can see among these cars when pushing the envelope, and why tuning them is so freaking hard.
Keep the power to chipped K03 levels and cars are a lot more even in output, most likely since the hardware is getting maxxed out.
#129
AudiWorld Super User
Dyno GB . . . who's in?!?
you know, FATS??
someone's gotta have some spare garage space . . .
someone's gotta have some spare garage space . . .
#130
I don't see it as "moving more air"
I see it as losing less air to turbulence and gap between the housing and the wheel.
I see it as moving the same amount of air (as this is dictated by the wheel geometry which hasn't changed), but losing less of that moved air because the tighter tolerance.
I understand what you are saying about compressor efficiency. I feel the true answer lies in-between our theories. It is operating more efficiently, but is also doing more work. However, I feel the additional work requirement is minimal...but I really don't have any hard data to back this up.
Another point not discussed yet is that the ECU will not respond the same way to the ZC turbo as a regular K04. The boost and timing curves will be different which makes comparison somewhat difficult.
I see it as moving the same amount of air (as this is dictated by the wheel geometry which hasn't changed), but losing less of that moved air because the tighter tolerance.
I understand what you are saying about compressor efficiency. I feel the true answer lies in-between our theories. It is operating more efficiently, but is also doing more work. However, I feel the additional work requirement is minimal...but I really don't have any hard data to back this up.
Another point not discussed yet is that the ECU will not respond the same way to the ZC turbo as a regular K04. The boost and timing curves will be different which makes comparison somewhat difficult.