As for my birthday day at the dragstrip, well, I wish it could have gone better. I got there early like I always do and a handful of people I know were there also. My buddy John and his silver Trans Am came also, and he usually runs 11.1-11.2 range at 126 mph. He knew his clutch was on its last day, so he was easy with the car at first. I think he ran a best mph of 128 and his best 60 foot was 1.48 but I forget if he ran a best e.t. timeslip. He runs a 436 sbc N/A setup but with a 6 speed out of a dodge viper.
Anyways, the suspension stayed the same all day: front struts at 0.5 out of 5, and rear shocks were at 2.5 out of 5. Front skinnies were at 37 psi all day and the rear drag radials at 19 and 19.5 psi. Used 93 octane shell pump gas for pass 1&2, but added 1/2 can of VP Octanium (lead free) for pass 3&4. So my WOT timing for pass 1&2 was 35.0 deg and for pass 3&4 I raised the timing to 37 deg. The weather was ok, but the DA was about 1,000 all day. As was the case last time, there were a LOT of oil downs, cleanups, people who walked away from their cars in the staging lanes and backlogged the whole flow, and in general the track just moved very slow. Sadly, I only got 4 passes.
Pass 1:
Did a 5 second mid rpm burnout. I tried a 1,800 rpm 2-step launch and left at 1,849 rpm. I had done some street tuning of the 2-step to try to get the fuel table dialed in for a 2-step launch. The brakes held, but the car bogged but only a little bit. AFR went lean 19.7 and then rich 9.6. Once it recovered, the rest of the run was pretty good. As we discussed in some previous posts, I raised the rev limiter and shifted a bit higher than normal. Shifted 1-2 at 6,648 and it dropped to 4,838 in 2nd gear. Shifted 2-3 at 6,552 and it dropped to 4,868 rpm. Crossed the line right around 6,236 rpm. ET was slow, but my MPH was the fastest ever for me, at 116.59 mph.
Video:
https://www.youtube.com/watch?v=0g2Q6T_apwI
Timeslip:
something is wrong with their clock, but only before 12 noon. This pass was actually at 11:40 am but the rest of my timeslips are accurate regarding the time of day. This is also the case with my track day 2 weeks ago. Weird.
Datalog:
-you can see the wild pink AFR right at my launch, and the bump in the red rpm trace prior to the engine recovering and running normally.
Pass 2:
Used the exact same tune file. Did a 8 second burnout and decided to foot brake the launch since the last run's 2-step launch went poorly. Launched at 1,769 rpm and then the engine bogged pretty bad...almost felt like I lost the transmission. So i got out of the throttle right away. Got on the throttle a little bit while coasting down the track looking behind me to see if I needed to pull off to the side. With everything intact and no smoke, I drove down the track and back to the pits. Looked over a few things and the datalog and could only determine that I needed to change the tune file. No real info to be gained from the datalog (as far as I can see??) but I drove the pits a bit to see if 1st gear and trans felt good, and it did, so I got back in the lanes.
Video:
https://www.youtube.com/watch?v=6DarbKRbvFg (that chevelle went a 8.91 !)
Timeslip:
Datalog:
Pass 3: Put in a fresh tune and one that I had made for the VP Octanium octane booster. Supposedly, it is an actual non-gimmick octane booster that raises octane by several numbers, not by points of a number. I put in half a can and put my WOT timing table to 37 deg. I would like yo do more research on this topic, but feel free to comment. Did a 5 second burnout. Footbraked the launch at 1,840 rpm which is right around the brake systems limit. Since I had just experienced two bogged launches I was expecting a 3rd so I was hesitant to go full WOT. You can see the upper green TPS line in the datalog, I did not get to wide open throttle until i got into 3rd gear. However I did shift 1-2 at 6,433 and it dropped to 4,713 rpm, and shifted 2-3 at 6,604 and it dropped to 4,825. Crossed the line around 6,082 rpm.
Video:
https://www.youtube.com/watch?v=RmhvxZ7t0T4
Timeslip:
Datalog:
Pass 4:
A bit frustrated, i just wanted a good clean full throttle pass knowing that the track day was ending and there were just so many track cleanups I was not going to get the 6 passes I had hoped for. Used the same exact tune file as pass 3, including the 37 deg of timing with the VP octane booster. Did a 6 second burnout and footbraked the launch at 1,450 rpm. Car hooked to a normal 1.67 sixty foot and the converter flashed around 2,720 (little lower than usual now). Shifted 1-2 a bit higher than I ever had at 6,763 and it dropped to 4,868 rpm...it actually tagged my new 6,800 rpm rev-limiter just a bit too. Shifted 2-3 at 6,605 and it dropped to 4,861. Went through the finish line around 6,203 rpm. Finally a good pass and with higher rpm shift points. Disappointed that it only resulted in a 12.005 at 114.09 mph.
Video:
https://www.youtube.com/watch?v=86Lb3GX_JTY
-If I had run my normal 11.80-11.85 I would have had a real cool side-by-side pass with that 2nd gen camaro! Even though I went 0.022 red, it would have been real cool side-by-side action. I actually started gaining a little back in the last few hundred feet.
Timeslip:
Datalog:
Log book:
Sidenote: I put the Go Pro on the drivers side to see how much the rear end is squatting on the launch. I tried it on the passenger side, but it fell off in the staging lanes 3 times when the car was just sitting there doing nothing. I'll get it to stick better next time, but in each above video is some footage of the rear squat.. This photo would have been from pass #1 or 2 when I was in the left lane:
Anyways. That's that. I hope to go back in early May for a Friday night TnT. An 11.7x at 117 mph would really thrill me . I also plan on moving ahead with the 6-point roll bar project in late May.