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Old 04-06-2021, 06:35 PM   #293
IROCZman15
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Join Date: Dec 2004
Location: Roxbury, NJ
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Ok, here it goes, been busy every day since Saturday, but finally got the bulk of my post-race day checklist taken care of.

I did go over to Island Dragway for Opening Day which was a daytime Test and Tune event. The weather was chilly, but not too cold. I overheard that Atco did not open today because it was too cold, but I am damn glad that island was open because I had packed and prepped the day before along with buying a ticket and the Covid waiver form the night before also.





Decent turnout of cars. DA was great all day, but there was noticeable wind throughout the day. Gates opened at 10, and racing was 11-4pm. There were at least 4 big oil downs so the track was dead for a bit occasionally. One oil down happened literally the pass before my last pass in my lane, but that one was in the shutdown area, still a long time to cleanup.



The car did good, but not great. I was (and still am) expecting more from the 3.91 gear swap, but I have to figure out what I am doing incorrectly which is not optimizing the gear swap. I basically ran the same type of timeslips that I was running in September and October of last year. 60foot, 8th mile, 1/4 mile and mph was all about the same. Expected a quicker 60 foot for sure, and more mph but did not see it. I did get my best ever 60 foot, but it was only 0.01 second better than 2020. Also a very slight improvement in the ¼ mile with a 11.805 at 116.13 mph compared to my previous best of 11.82 at 115.96. So I am indeed confused as to what needs to be optimized. I know I somehow have to hit the launch harder (without a Transbrake) and I am nailing my shift points…so feel free to chime in as to why/how the gear swap isn’t showing track results yet. On the street, the car pulls noticeably harder in all gears. The gear swap is great on the street, but I did not feel it at the track, and the timeslips verified my seat-of-the-pants opinion also. The converter is flashing higher now with these gears and I am coming through the finish line right at peak HP instead of below it like I had previously been. See my engine dyno sheet on page 1 of this whole thread. Peak tq is at 4,800 and peak hp is at 6,000 rpms.

I made no changes to tire pressure or shocks or suspension all day
- Tire pressure front 37psi on the skinnies 19psi rear on the MT drag radials
- Front struts were left on 1/5 so that’s loose and rear shocks were at a 2/5 slightly loose



Pass 1: 4.5 second mid rpm burnout. Launched at 1,211 rpms via the 2-step. The converter flashed at 3,171 rpm. Shifted 1st-to-2nd at at 6,557 and hit the limiter for a split second., and it dropped to 4,898 rpm in 2nd gear. Shifted 2nd-to-3rd at 6,503 and it dropped to 4,871. Crossed the finish line around 6,198 rpm. 34.8 deg timing at WOT with a 12.7 target AFR.

VIDEO: https://www.youtube.com/watch?v=HFE1ON2GPts








Pass 2: Used the exact same tune file. 6 second burnout at mid rpms. Launched at 1,752 rpm via using the footbrake. Converter flashed at 3,127 rpm. Shifted 1st-to-2nd at 6,504 and it dropped to 4,762. Shifted 2nd-to-3rd at 6,501 and it dropped to 4,907 rpm. Crossed the finish line at 6,223 rpm. Timing was 34.8 and a target afr of 12.7

VIDEO: https://www.youtube.com/watch?v=ZUqr7kcrRkQ









Pass 3: Some slight changes in the tune, I raised the rev limiter and added 0.3 deg of timing. I also applied the learn data to the VE table and it took out a good amount of fuel on the wot part of the table. I was hesitant to do this. Did a 7 second burnout at mid-high rpms. Wanted to try launching off the 2-step at a higher rpm to see what the brakes could hold. Launched at 1,821 with my foot full on the throttle while on the 2 step. Car began to roll through the brakes so I just let it leave. The converter flashed at 3,072rpm, but about 1.5 seconds into the run the engine went soft and I got out of the throttle. Aborted the run but nothing seemed awry on my gauges so I coasted the rest of the pass and looked over the data. Saw a huge lean spike in the datalog and thankfully my 100% open CL comp limits saved my motor from going way lean on me. CL comp went up to almost 90% with adding fuel to correct the lean condition and I am very thankful for that. Still unsure what caused this.. I do need to dig deeper into the datalog, but I wanted to post stuff here first to see if anyone had any ideas. ??


VIDEO: https://www.youtube.com/watch?v=fSljvt9PaAQ













Pass 4: used a different version of the tune from the beginning of the day. 5.5 second mid-rpm burnout. Launched at a 920 idle from the footbrake. Converter flashed at 2,995 rpms. Shifted 1st-to-2nd at 6,573 rpms and it dropped to 4,790. Shifted 2nd-to-3rd at 6,513 rpms and is landed at 4,871 rpms. Crossed the line at 6,172 rpms and timing was at 35.1 deg and a 12.7 target afr.

VIDEO: https://www.youtube.com/watch?v=QH9buNy6DPc










Pass 5: Only changed the timing back down to target 34.8 at wot and raised the target afr from 12.7 to 12.8 at wot. Did a 7 second burnout at 3,500 rpm. Launched the car at 2,142 rpms on the footbrake. I did not expect it to hold at this high rpm, but it seemed to! Converter flashed at 3,075 rpm. Shifted 1st-to-2nd at 66,58 and it dropped to 4,916 rpm in 2nd gear. Shifted 2nd-to-3rd at 6,551 and it dropped to 4,927 rpms. Crossed the line at 6,311 rpms.

VIDEO: https://www.youtube.com/watch?v=z5M338pm-iM






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Loaded up the car with all my tools, gear, and hit the road home. Drove home with no problems. It was a good day. A good shakedown day after 5 months of no dragstrip passes. Nothing went wrong, just I did not get any timeslips with a 1.5x sixty and an 11.5x e.t., so I have some work to do to hit my goal before venturing into the nitrous realm. I did notice on a few passes that my oil pressure is above what the dash gauge reads. gauge reads to 80 psi and sometimes at WOT the oil pressure is above it, probably like 90. it settles right back down afterwards. this only happened at the end of last year, and everything has been fine. remember my posts about this and my oil analysis and pressure testing with an extra pressure gauge? its still doin it. ??

I am wondering if I need to tighten up the rear suspension a tad. On the return road I heard some suspension parts scuffing, and unless it’s the torque arm hitting the tunnel from my adjustments this winter, I might have the suspension too soft? Maybe the car is squatting too much on the launch? Its hard to tell from just one of Jan’s photos, what I really need is a video. The photo could be taken halfway through the launch’s squat, or at max squat, who knows.




Feel free to comment, suggest stuff, or whatever. Videos, datalogs, photos, are all provided to helm out. Thanks!
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Last edited by IROCZman15; 04-07-2021 at 08:38 PM.
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