Well on Saturday night I arrived in lovely Miami, FL. After an exciting and frustrating day in Landshark Stadium on Sunday, I drove to Active Autowerke for my 9:30 am appointment for custom dyno tuning on Monday. I was told I would be out of there no later than 12:30 pm which was good since I had a 10 hour drive home ahead of me.
Things started off a little slow as Omar got the car in their system and placed the floor mat protector and customer number on the rearview. The car was pulled onto their Mustang Dynamometer at 10:00 am and strapped down. I had never had this car or any previous car dynoed on one of these so it was a learning experience for me. The tuner pulled the car on the dyno and then ran the wheels while unstrapped to center the car on the rollers. He then proceeded to do the standard strapping in the front and the back. He then put what looked to be a custom made pipe used to hold the O2 sensor for the air fuel readings in one of my 4 exhaust tips. It was secured to the exhaust with a wire so it wouldn't come flying out. I have seen previous shops with Dynojets use a long thin tube which is clamped to the exhaust tip. The AA solution seemed alot better, although I was surprised they didn't prefer sticking the O2 sensor directly in my mid pipe since the car is catless. He then proceeded to move a very large box fan in front of the car and tighten that down. That was followed by 2 smaller blue fans that each were angled to shoot at the radiator. My normal dyno only uses one of these blue fans on a ladder in front of the car for cooling so this was more cooling than I was used to for dyno runs. It was also interesting that they didn't run a wire to the coils to get a tach/RPM signal which is required on a Dynojet. I asked him about that and he said the dyno calculates it. I guess this accounts for why the dyno plot before says I made max power before 8200 RPM when I know the car pulls past that on a Dynojet.
Now that the car was ready the tuner got his laptop and plugged into the OBD port to capture the settings of the car. He made some pulls and some steady rpm runs then went in the back where I guess he does the programming. At this point it was time for an early lunch, and I got to see an actual lunch truck come by the shop and hit the big air horn meaning it was chow time. 30 minutes later, and he came out and did some more runs for the baseline and then did the flash. He made some more pulls and then went back in the room again to do some more work programming I guess. He came out and flashed the car again and did some more pulls at which point he was happy with the car. He told me the car made good power and said the car went from 338 to 358 which made me very happy. Better yet the car was done before 12:30 pm as promised.
The car was very loud on the dyno and many of the AA employees came over to check it out including one guy who crawled under to look at my RPi exhaust. I have included an image of the dyno plots from the baseline and the AA tune. The important thing to note is how the car makes more power throughout the RPM range and how AA was able to richen up the A/F from 4000 to 6000 RPM and lean it out from 6500 RPM to rev limit. Air temps were between 80 and 90 degrees during the dyno runs in the lovely hot and humid Miami weather. Overall, I am very happy with the tune. The most noticeable difference is on cold start up where I guess they disabled the strange M3 cold startup procedure that caused my RPi exhaust to wake the entire neighborhood on startup. Now the car starts and stays quiet instead of how it used to take a couple minutes at least before the car quieted down. I plan to take the car to my local Dynojet dyno next month where I baselined my car before any modifications at 340 whp. Any comments, questions, or suggestions are welcome and appreciated.
RPi Full GT Exhaust