[s-cars] Dragstrip day

[Djdawson2@aol.com]

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