Data
One thing had been troubleshooting after our first race with the V6 was with the tach dropping out. While during the race I just unplugged as many accessories as I could thinking we had a voltage problem, what I discovered was that it was actually an issue with the datalogger. The tach signal from the computer was being drawn down by the datalogger and the signal would go low enough the tach wouldn't recognize it any more. The rpm switch still worked and the datalogger was logging the RPM, but the tach was more important than the datalogger. Due to this problem, I decided to remove the tach signal from the datalogger when we went to ORP. There was also a datalogger I had been interested in that better real-time feedback called Race Capture. I finally decided to pull the trigger and pick up a Race Capture system and got that wired in.
Major pros for the Race Capture system are the ability to connect to a tablet for data display (expensive option for most loggers) as well as the ability to do telemetry (not even an option for most systems). I had previously been using a Race Technology DL1, which is a great unit with very comprehensive analysis software. Unfortunately with the DL1 it feels like everything is nickel and dimed. You want to use the general purpose output pins? Need to pay to unlock. Want to sync video? Need to pay for a license. Want to use the second built-in serial port? Need to pay to unlock it.
Data is so incredibly useful, I really feel it is one of the reasons we were able to go from a new team placing 28th our first time out, to winning races. If you have someone fast on your team, you can compare laps and see what they are doing that makes them faster. If you get a chance to have some local hot shoe or pro driver, that is the ideal to see what the car is capable of and what you are leaving on the table. I saw Randy Pobst drove a 240SX at Daytona in an endurance race.. one day I hope to get him in this car.
Another thing I didn't mention before, is I had finally figured out our issue with the car not starting. While I had ziptied the key directly to the side of the antenna, it needed to be centered. Once I shimmed it into the center of the antenna, I have never had an issue with the NATS (Nissan Anti-Theft System) again.
The First Race with Aero (7/7/2018) - 7 hours - Portland International Raceway:
The weather was looking glorious for our July race. Not too hot, but clear and dry. We were pitted next to this amazing looking Mustang with hand-made fenders! Lots of horsepower, but a very unfortunate choice of tire (no grip).
We went out for qualifying, feeling the car out. The power steering is a little light for my tastes, but it does it's job. Our brakes feel a little soft, but they always have after putting the Wilwood calipers up front (more fluid to push). We qualify in the fastest class A, which is where I like it. If you are in B class and towards the front, you are always in danger of being bumped to the very bottom of A class. In A class, the only thing to watch out for is running "too fast" and getting to the Super Dog class, but our car is never fast enough to hit those times.
Nathan Feigion takes the green flag in 20th place. Not to worry, it's a long race. Settle in and start putting in some consistent quick laps. Nathan makes quick work of the traffic, getting up to 6th place on lap 9. Our previous lap record at PIR was a 1:31.3, and Nathan is already demolishing that. By the time he runs a 1:29.4 on lap 35 he is in 1st place, and has put in eight laps faster than the previous record. The aero and suspension are definitely working! Nathan pits in 1st place on lap 53.
Dave goes out in the car next, and we are currently in 2nd behind the #37 Red Line Oil Racing BMW. Dave fights back and forth with the #4 Miata until the #37 pits and we are back into 1st place. Dave runs a very respectable 1:31.8, his fastest lap ever! Dave pits on lap 113.
I get in the car for the 3rd stint, and the car feels really good! I hadn't driven anything with any downforce before, so I wasn't sure what to expect. I don't have that sensitive of a butt for this kind of testing, but in the medium speed corners (65-70 mph) it was a feeling of, "Ok, and it's going to start letting go right.. oh wait.. it didn't.." It took some learning to trust the car was going to stick and keep pushing a little more. If you were to just plop me in a car blindfolded and have me drive it (after removing the blind fold of course), I don't think I could tell you if it had downforce or not. But even with my insensitive butt I could tell this was working better than before. The higher speed corners (80+ mph) were where the car really seemed so much more stable and confidence-inspiring. The car is a blast to drive, but towards the end of my stint I notice the right front is developing a vibration and the brakes are getting a little softer. Uh oh, this isn't good. I run a personal best 1:30.5 and pit in 1st place on lap 180. At this stage of the race Finally Racing #177 BMW, Preying Mantis #67 BMW, and the Race Invaders #13 Ecotec swapped Miata are all in the hunt just behind us. After I pull in the pits we inspect the right front, but we are not able to find anything obvious. The wheel spins fine, and the slop is difficult to gauge because these shocks can rock at full droop.
Nathan heads out with the #67 BMW hot on his tail. The vibration is getting worse and the brakes are getting softer. Nathan is having to pump the brakes up at this point to get them to work properly. #67 has their fastest driver in the car (Cody Smith), and he gets around Nathan. At this point we know the failure is a right front wheel bearing, and we need to just get it to hold together to finish the race. Nathan backs out of it and gets it to hang on to the end and we finish in 2nd place!
So now that the race is over, it's time to figure out what to do about the bearing. We are using aftermarket conversion 5-lug hubs, and since we have never had a wheel bearing failure we haven't prepared a spare. My personal car uses S14 hubs which use a different bearing. Nathan Feigion's drift car uses conversion hubs and luckily is not too far away. He heads back home to yank a hub off of his drift car while I prepare Blue Bayou for it.
These were Timken bearings that had been repacked with Redline CV-2 grease. Apparently we're putting a lot more load through the suspension with all this extra grip..
These ball bearings are not quite so smooth and round any more!
After we got the new hub swapped in there, we were ready to race another day!
So is aero worth it?
These charts are not entirely apples to apples, but this really shows some of the difference of aero. You can see how the lateral forces (top graph) for blue (aero) are higher all over than red (no aero). The speed chart on the bottom really shows how much the minimum speed is brought up in some of the corners. While you can see the slower acceleration on the straight from the drag, it is much more than made up for in the cornering speed.
Video overview: