I was! It was last minute on Friday when two of my buddies told me they were thinking of going, so I decided to take advantage of the only non-rainy day this weekend and go on Friday night's TnT. I have to get all that written up and the videos/logs/timeslips are still on my desk.
Its a shame it took me this long to get to put all the photos, videos, and files in one spot, but here is most of it. Will add more later on.
Took the car to the Chassis Dyno back on September 8 for a second go at it. The new distributor had been working perfectly so I was good on that respect. The goal for the day was to find real-world torque and hp curves and see how different it is compared to the engine dyno printout that was from when the engine was first built brand new (no accessories, open headers, dyno stand setup). Below is that printout, which was from February of 2020 at Nyes Racing Engines. I also wanted to see if I could get the jetting on teh nitrous checked. I strapped a Go-Pro camera to the underside of my hood also, pointing directly at my fuel pressure gauge so see if I lost fuel pressure at all during a WOT pull.
Got the car strapped down and discussed what we needed to. I had realistic goals for peak power, knowing that I'm sure my numbers have diminished with an automatic transmission, my 12 bolt, front accessory pulleys, and 3 years of significant wear and tear (113 dragstrip passes and 57 autocross laps, plus untold street activity). I had hoped for at minimum 400 wheel hp and 375 torque on all motor runs. As a high number I was thinking 420 rwhp, as thats how it feels driving it.
I said, for the hell of it, lets do the first pull with the air filter and lid on.
Dyno Pull 1:
35 deg WOT timing, 93 octane pump gas, targeting a 12.8:1 AFR, air-filter and lid on, .035 gap on Autolite 3923 plugs, 3rd gear WOT, only pulling to 5500for now. at WOT converter flashed to right about 4800 and AFR held pretty close to 12.8 on the drivers side o2 sensor which is the datalogged holley one. The datalog shows that it puled to 5848 rpms, but the dyno graph shows it was loosing power rapidly after 5,100 rpms.
(I do not have a video for this or the second dyno pull.)
354 hp and 364 tq
Dyno Pull 2:
same timing, same everything except we took the air filter and lid off.
Printout is not printable for some reason, but the numbers were
From a steady 3100 rpm to wot the converter flashed to 4836 rpms and the afr got a little nutty with going lean. it caught itself and leveled out and pulled to 6086 rpms on the log,
366.4 hp and 375.2 tq
Dyno Pull #3
Same settings, decided to lock up the converter during 3rd gear.so, from a 3rd gear 2644 rpm and the converter locked up, it never flashed, and just climbed slowly to 6285 rpms
The AFR was a bit nutty for a few seconds early on. I'll have to check those VE cells, they may have never been cleaned up since I never usually lockup 3rd gear and go WOT
No hp gain from previous pull, but it lost some torque.
367 hp and 367 tq
https://www.youtube.com/watch?v=tUJpgkzWZQo
Dyno Pull #4
Decided to not-lockup the converter, and only to change the ignition timing and see if it gained any power going from my normal 35 deg instead to 37 deg. It picked up a little bit, but not sure if its justified to push the limits with 37 deg for that small of a gain. To Be Determined.2499 rpm steady to wot, and for some reason the log appears likethe converter was locked since there is no flash. With 37 deg of timing there were no big signs of detonation on the rpm trace of the log and the closed loop comp numbers I can live with and adjust what I need to from this data.
https://www.youtube.com/watch?v=5whX4hzQxKo
We had previously decided to check spark plug #7 throughout the day, mostly for the nitrous runs.
We used the same plug on all four of these above all-motor pulls and here is a photo of it.
I mounted the go Pro under the hood , and the shaking in the video is the hood vibrating, the engine is not shaking around that much. This video is probably pull#2. to get a video of the mechanical fuel pressure gauge and making sure it stayed close to 60 psi.
https://www.youtube.com/watch?v=32fqQbRLgCA
While I was pretty happy to see that how I have recently been tuning the car was decent, ... but I was definitely pretty shocked about the really low peak power numbers in all 4 motor pulls.
The engine dyno made peak power 531 at 6,000 rpms with 36 deg timing and I could only manage to put down 374 hp at5,600 rpms. Not expected, and mathematically that works out to be exactly a 30% powertrain power loss. Woah!* If I am only truly putting 374 hp and 378 tq to the tire, I am surprised I run 11.60s and 11.70s at the track with a 3600 pound setup. Interesting. But my car has always felt underwhelming most times, so therefore it does make sense.
So overall peak numbers: 374 hp (pull 4) and 375 tq (pull 2). I will have to dig into looking at the power curves a bit better to use them to determine if I should still try to shift past 6,000 rpms like I usually do?
Nitrous stuff in the following post.... might be a few more days before I can get to typing that up.