DML,
I tried out the 700+cfm Holloway stage II throttle body at the track
Saturday. Got some interesting results. The conditions: 75deg F, 70%
humidity, 29.99 Atmospheric pressure.
I started with the Stage I TB (see pics on the DML) this TB has stock
butterflys was unshrouded and "cleaned up". disconnected the battery for 5
min, reconnected and lined up: (note final mph are off due to track
"problems"...
Run 1, Stage 1 TB:
R/T .628
60ft: 2.319
330ft: 6.395
1/8ET: 9.801
1/8 mph: 71.69
1/4 ET: 15.32
Mph 89.87
Run2, Stage 1 TB:
R/T .833
60ft: 2.216
330ft: 6.282
1/8ET: 9.684
1/8mph: 71.74
1/4 ET: 15.209
Mph 89.72
all runs: transmission in drive. ended the test of the stage I since the
track was getting crowded and the Big TB was calling my name!
Run 3: Stage 2 TB
R/T .617
60ft: 2.304 (lots of tire spin)
330ft: 6.404
1/8ET: 9.832
1/8 mph: 71.19
1/4 ET: 15.409
Mph 88.89
Run4: Stage 2 TB
R/T .759
60ft: 2.275
330ft: 6.362
1/8ET: 9.781
1/4 ET: 15.348
Mph 89.04
Run5 Stage 2 TB:
R/T .753
60ft: 2.302
330ft: 6.379
1/8ET: 9.782
1/8mph: 71.77
1/4 ET: 15.305
Mph 89.77
Run6 Stage 2 TB, Manually shifted
R/T .674
60ft: 2.213
330ft: 6.363
1/8ET: 9.817 (hit the rev limiter 2-3shift, ouch)
1/8mph: 70.83
1/4ET: 15.410
1/4 Mph: 88.92
hit the rev limiter on 2-3shift (manually) kinda slowed me down...hits like
a ton of bricks.
Note the run6 60 ft time vs the run 2 60ft time. Extra wheel spin and still
the same time!!!
My impressions:
The R/T loved the Stage I TB combined with the exhaust mods and JETII
module. It felt like it would go faster as the computer "caught on" to the
combo. A great combo for the street cruiser thats wants snappier
performance from their R/T for minimum bucks. I think my combo of mods has
scrubbed around .5-.6 seconds in E/T from the stock config. The Stage II
TB presents some mysteries/opportunities. On the track, it felt "softer" in
the mid range but pulled hard to redline after about 2500rpms. I had a
significant problem with traction with the stage II TB as well but not with
the stage I BUT my 60ft times (2.216 stageI vs. 2.213 stageII are
equivalent! More grunt at the botom from the bigger TB, go figure?). Its
hard to tell about the traction problem since the track had "aged" over the
afternoon and probably had gotten more slippery since the first run. I
didnt see the 14s I was hoping for, nor huge improvements from the big TB...
BUT On the drive home, I noticed a definite surge at WOT at freeway+ speeds.
I continued driving putting about 2 more drivecycles on the truck. At that
point I felt that I am getting to 90mph from 65 mph faster than ever, but
after "extended" WOT at 3K + rpm I get the surge. This says to me that Im
too lean at the top end. The R/T never surged with the stage I TB. Hmmm
Frank suggested removing the JET chip to see if the WOT gets better. Ill do
that this afternoon. Sounds like more mods are needed... New comp mapping?
Bigger injectors? Ill keep the list posted on what those might be as we
get further along in the development process... Any suggestions to make the
big TB work?
BKB
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:10:33 EDT