Last updated 10/16/2000

I figured some people would like to see what the Downing/Atlanta supercharger does for a 1.9l.

Right before I installed it I did some benchmarking using OBDTOOL to plot vehicle speed against elapsed time and did various runs. I just repeated some of those runs tonight.

All the pre numbers are on my car with the Fogged airbox, big bore throttle body and Remus exhaust. The post numbers adds the Downing/Atlanta to my car. Car had a full tank of gas during each test.


Pre-9.98 Post-8.64

Pre-13.82 Post-11.52
30-50mph 3rd gear:

Pre-5.25 Post-3.71
50-70mph 3rd gear:

Pre-5.35 Post-3.8

I did the first two tests from rolling starts to eliminate the launch as a variable and it gives a better picture of real world power.

From a review I have comparing the Z3 2.8l to a Boxster they listed

30-50mph 3rd gear:

Z3 2.8l-4.2 Boxster-4.7

50-70mph 3rd gear:

Z3 2.8l-4.2 Boxster-4.3

I also have 30-50 and 50-70 in 5th pre but I haven't had a chance to get the post numbers yet.


I also have Road Dyno which I've done a couple of tests with. Road Dyno probably isn't good to compare against other dynos as its results will vary depending upon how accurate you input the test weight. It does seem to be very consistant though so it should be fine to compare against itself which is really what I was looking for. Still the numbers it gave me on my car are about what I expected.

The full details of the run are available here.

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