Here are the results of my dyno runs at Pro Dyno Tech on May 31, 2008. Their dyno is a Land & Sea Dynomite dynamometer. From what I've read, it gives similar results to a Mustang or Super Flow dyno. I made 6 pulls in total; 5 naturally aspirated (no nitrous), and then I made 1 pull with a 100 shot of nitrous.
I had been doing tuning myself with HP Tuners and a PLX wideband, which is installed in the y-pipe right after the merge. The dyno had an Innovate LM-1 wideband that they logged along with the dyno pulls, and I used it for comparison. I had a couple of very interesting things happen with the wideband. The first thing that I noticed was that my actual AFR was ~0.5-0.8 richer than the commanded AFR. When doing tuning on the street, the actual AFR is always very close to the commanded AFR. I have heard that it is relatively common for cars to run more rich on a dyno because the load it places on the engine is different than driving.
The second thing that I noticed was that my PLX was reading 0.8 to 1.0 leaner than the LM1. I wasn't sure which was more accurate, so I gradually leaned it out on each run and monitored for the presence of knock retard. I finally saw 0.2 degrees on the final NA pull, where the PLX read an AFR of 13.3 and the LM1 read an AFR of 12.4. I'm not really sure which was closest to being correct, but the most important point was to note that I wanted to run just a bit richer than that pull.
I had been planning to do at least one pull with nitrous, however right before leaving for the dyno, I had a problem with the bottle heater and it wouldn't turn on for some unknown reason. I checked the bottle pressure and it was ~900 psig, and the heater keeps it at 1050 psig. I realized that the run would be quite rich but I decided to try one pull anyway, just to see what the results would be.
Anyway, the results are shown in the table and pictures below. The best NA run with the torque converter unlocked was 381 horsepower and 377 ft lbs of torque. I also attempted one pull with the torque converter locked, and it was 384 horsepower and 374 ft lbs of torque. Using the 100 shot of nitrous resulted in 470 horsepower and 450 ft lbs of torque.
|
Time |
Torque Converter Status |
Nitrous |
Timing (degrees) |
Average actual AFR (PLX wideband in y-pipe) |
Average actual AFR (LM1 wideband in tailpipe) |
Knock Retard (degrees) |
Peak horsepower (hp) |
RPM at peak horsepower |
Peak torque (ft lbs) |
RPM at peak torque |
| 11:11 AM |
unlocked |
none |
24.0 |
12.3 |
11.5 |
0.0 |
368.7 |
6100 |
357.8 |
4800 |
|
11:18 AM |
unlocked |
none |
24.0 |
12.7 |
11.7 |
0.0 |
376.7 |
6100 |
379.9 |
4500 |
|
11:23 AM |
unlocked |
none |
24.0 |
13.1 |
12.1 |
0.0 |
379.0 |
6200 |
379.7 |
4300 |
|
11:26 AM |
unlocked |
none |
23.5 |
13.3 |
12.4 |
0.0 |
381.0 |
6100 |
376.8 |
4300 |
| 11:29 AM |
locked |
none |
23.5 |
13.3 |
12.4 |
0.2 |
384.3 |
6000 |
373.5 |
5000 |
| 11:35 AM |
unlocked |
100 |
23.5 |
11.8 |
10.8 |
0.0 |
470.1 |
6100 |
448.7 |
4500 |
