[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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