US41 Test & Tune
Here are my time slips from test and tune at US41 on October 12, 2007. As you can tell from the scans, I was car number 4. I made 8 passes on motor only (no nitrous), and then I made 2 passes with a 150 shot of nitrous. I was running street tires at 32 psig.
My best run without nitrous was 12.90 @ 108.85 MPH and my best with the 150 shot of nitrous was 12.09 @ 116.2 MPH. I am pretty sure that the nitrous is not operating correctly since I only gained ~0.8 seconds and ~7 MPH with the 150 shot of nitrous. (60' times were almost identical on the runs) Also, I weighed the nitrous bottle before and after, and I only used just over 2 lbs of nitrous in total for both runs. According to many other nitrous users, a 150 shot should use about 2 lbs for one run.
I did some tuning with the A/F ratio on the NA runs and I tried 12.5:1, 12.8:1 and 13.1:1. The leaner tuning seemed to slow slight but noticeable gains. I also tried adjusting the shift points, and found that shifting closest to redline yielded the best results. The A/F ratio on the nitrous runs was ~11.5:1, which is a bit richer than I want (aiming for 11.8 ), but I didn't have a chance to change the jets between runs. (the runs were <5 minutes apart, LOL)
