[s-cars] Dragstrip day
Mesa Cycles
info at mesacycles.com
Tue Sep 27 09:14:09 EDT 2005
> ------------------------------
>
> Message: 9
> Date: Mon, 26 Sep 2005 20:53:55 EDT
> From: Djdawson2 at aol.com
> Subject: [s-cars] Dragstrip day
> To: s-car-list at audifans.com
> Message-ID: <8e.30917426.3069f223 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> Well...
> Finally got the car to the dragstrip. I had my newly installed 928 MAF.
> Temps were 81-85 degrees by my dash display, and the dragstrip is at 2700ft.
> The runs were made with pump Chevron 91 octane gas.
>
> The results were less than pleasing... but I have to pass them along as data
> points, or I'd be a cheater.
>
> 4 runs... 13.13 @ 106.48, 13.23 @ 100.85, 13.19 @ 103.10 and 13.20 @ 100.81.
>
> I don't believe I can draw many useful conclusions yet, as the 928 MAF isn't
> adjusted properly. The car refused to pull hard in 3rd gear, and somehow,
> the early run times (60ft, 330ft, and 1/8 mile) had NO effect on the overall
> time.
>
> My best 60ft time was 1.805 sec. My worst launch resulted in a 2.244 sec
> 60ft. Ironically, the run with the 2.244 60ft was my quickest and fastest
> run,
> when it took me nearly .5 seconds longer to complete the first 60ft. What?
> Why?
>
> I discovered A/F ratios were pushing into the mid 13s in 3rd gear. As soon
> as this would happen, the timing would back off. I never had a run where the
> engine would pull hard in all gears. Very frustrating, and no way to adjust
> at the track. From my dyno experience, I know the engine tends to make its
> best power when the A/Fs are in the high 10s when under full boost and WOT.
> Improvement is certainly available here.
>
> Next, the clutch. The Centerforce isn't up to the task. You can't launch
> aggressively, or it will go into an uncontrolled slip. Gotta do something
> about this if I'm going to see good dragstrip results. Other cars that were
> making it to 106mph were recording mid 12s on the ET.
>
> Finally, the gear ratios. Quandry here... 3rd gear at 8500rpm still won't
> get you to the end of the track. However, shifting into 4th is done so late
> that it becomes a penalty. As a result, my best time and speed (13.13 @
> 106.48) was achieved by running 3rd gear to 8500rpm, pushing in the clutch
> and
> coasting through the trap.
>
> So, back to the dyno. Need to get that MAF dialed in. I will dyno and tune
> the engine this weekend to get it running right. And then I'll be back to
> the strip on Oct 8th for another try.
>
> All wasn't lost, however. When you can run next to a new Z06 (I think was
> the designation) at still beat him by 4 or 5 carlengths in a heavy 4 door
> sedan... you still feel pretty good, and generate a lot of curiosity in the
> pits.
> Stay tuned.
> Dave
>
>
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> End of S-CAR-List Digest, Vol 23, Issue 95
Dave,
What are you running for a turbo and software?
Russ Murphy
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