408 N/A Shake Down Passes
06-01-2009, 08:53 AM
#1
408 N/A Shake Down Passes
No Nitrous, just N/A.
I was able to get to the track two weekends ago for some official shake down passes and make sure everything is in good working order. Anyway, the weather was absolute crap for drag racing, HOT and Humid with low barometric pressure (85*, 69%, 29.90" according to weather.com however track temps were higher for sure). That equates to a density altitude of better than +2500ft at race time. Regardless, I had a good time.
First pass:
60ft 1.946
330 5.478
1/8 8.443
MPH 82.06
1000 11.044
1 /4 13.262
MPH 101.58
So I look at the scan and see 0 KR, AFR is right where I wanted it (a tad rich) and nothing seems out of line except for high IAT's which were 108 at the start and went to 101 at the end of the run. I reflash with 2* more spark advance across the WOT + 3600rpm area (25* total) and bumped my shift points to 6300 for both 1-2 and 2-3. After about an hour cooling off I go again however the damn track officials forgot to change back to ¼ mile times from the 1/8 mile times from the Jr. dragsters so I only got the 1/8 mile times to compare.
60ft 1.981
330 5.421
1/8 8.311
MPH 83.16
So the changes made an improvement however I do not have the ¼ times to compare. I felt cheated so I immediately hot lapped the truck with no cool down and ran the same times as my first run. No KR to speak of and the truck ran well for its first time out.
I am not a fan of "ricer math" however I cannot discount the weather conditions we were racing in. A friend was with me and was a half second slower than he normally runs and if you do the math to correct to sea level air, I would have been doing 12.9's on the first pass and most likely 12.7's on the second pass. I was at full weight and then some to boot. Now that I have some numbers to correlate, I will bump the timing to 27*, retune the MAF table and Ve for any changes. Once I am comfortable with the tune, I will shift in the motor's powerband (shift at 6600 or so) and should be able to shave a few tenths. I don't expect to hit the track till the weather gets cooler again and by then, I will be ready for the spray. At least I got some good logs to go over.
I feel mid to low 12's should be fairly easy after I am done with the WOT tuning and in good weather. One item I may address over the winter is having the converter stalled higher. I feel a 4000 stall converter will shave another few tenths. Of course, I would like to see what happens when I spray the pig first.
Now its time to clean her up and enjoy the summer cruise nights.
I was able to get to the track two weekends ago for some official shake down passes and make sure everything is in good working order. Anyway, the weather was absolute crap for drag racing, HOT and Humid with low barometric pressure (85*, 69%, 29.90" according to weather.com however track temps were higher for sure). That equates to a density altitude of better than +2500ft at race time. Regardless, I had a good time.
First pass:
60ft 1.946
330 5.478
1/8 8.443
MPH 82.06
1000 11.044
1 /4 13.262
MPH 101.58
So I look at the scan and see 0 KR, AFR is right where I wanted it (a tad rich) and nothing seems out of line except for high IAT's which were 108 at the start and went to 101 at the end of the run. I reflash with 2* more spark advance across the WOT + 3600rpm area (25* total) and bumped my shift points to 6300 for both 1-2 and 2-3. After about an hour cooling off I go again however the damn track officials forgot to change back to ¼ mile times from the 1/8 mile times from the Jr. dragsters so I only got the 1/8 mile times to compare.
60ft 1.981
330 5.421
1/8 8.311
MPH 83.16
So the changes made an improvement however I do not have the ¼ times to compare. I felt cheated so I immediately hot lapped the truck with no cool down and ran the same times as my first run. No KR to speak of and the truck ran well for its first time out.
I am not a fan of "ricer math" however I cannot discount the weather conditions we were racing in. A friend was with me and was a half second slower than he normally runs and if you do the math to correct to sea level air, I would have been doing 12.9's on the first pass and most likely 12.7's on the second pass. I was at full weight and then some to boot. Now that I have some numbers to correlate, I will bump the timing to 27*, retune the MAF table and Ve for any changes. Once I am comfortable with the tune, I will shift in the motor's powerband (shift at 6600 or so) and should be able to shave a few tenths. I don't expect to hit the track till the weather gets cooler again and by then, I will be ready for the spray. At least I got some good logs to go over.
I feel mid to low 12's should be fairly easy after I am done with the WOT tuning and in good weather. One item I may address over the winter is having the converter stalled higher. I feel a 4000 stall converter will shave another few tenths. Of course, I would like to see what happens when I spray the pig first.
Now its time to clean her up and enjoy the summer cruise nights.
06-01-2009, 11:21 AM
#3
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Good job. 
That is very good for shakedown runs.
I went to the track Saturday and managed a 1/8 of 8.7 and 1/4 of 13.7 with my 408 at the CA Speedway and on Thursday I did a 8.5 in the 1/8 at the Irwindale Speedway. I was told the DA was 2500 for my Saturday runs.
What are your mods besides the 408? And what is your cr on that motor?
That is very good for shakedown runs.I went to the track Saturday and managed a 1/8 of 8.7 and 1/4 of 13.7 with my 408 at the CA Speedway and on Thursday I did a 8.5 in the 1/8 at the Irwindale Speedway. I was told the DA was 2500 for my Saturday runs.
What are your mods besides the 408? And what is your cr on that motor?
