2012 American Snowmobiler/DTR NY Shootout dyno certification, etc.

2012 American Snowmobiler/DTR NY Shootout dyno
certification, etc.
This year, we had Arctic Cats supplied by D&D Powersports of Loweville, NY since
Dale Fredericks was unable to. D&D also supplied the Yamaha “120” and “150” class
machines (class designation is determined by AmSnow). Woody’s Performance Center
(Yamaha dealer) in Topsham, ME brought us a brand new Nytro with a Yamaha supplied
and warranted MPC centrifugal supercharger system installed. This estimated 180hp
machine would be run as a demonstration against the F1100 turbo in the “Unlimited”
stock class. As has been the case for 23 years now, Smith Marine brought the SkiDoos.
And for the second year in a row, Fun Unlimited in Gouverneur NY supplied the Polaris’.
Since my Shootout partner George Taylor died earlier this year, Tom Smith (former
owner of Smith Marine) has taken over the organization and supervision of sled selection
and setup at each participating dealer. After random crate selection at each dealership, the
sleds were set up, studded and loaded into a monstrous sled trailer for delivery by Tom to
the dyno for “certification”. Last Monday and Tuesday, the dealers sent technicians to
DTR to assist in the dyno testing.
120 class sleds
This is the third Cat 1100 normally aspirated stocker I’ve tested since its debut as the
Jaguar Z1 in 2007. In 2007 (scroll down to 4/22/2006 to see that stock evaluation) the
preproduction 07 Jag Z1 made 132hp at 8900rpm just below the rev limit. Last year, we
thought that the F1100 shootout sled was “stuck” in reverse mode, limiting peak revs to
5800, and making a flat 108hp from 5100-5800rpm. But after testing the 2013 F1100 and
seeing a similarly flat 111hp from 6500-8900rpm, I went back and reviewed last years
F1100 test data. Sure enough, I found that the dyno was improperly programmed for 1/1
direct drive instead of 1.5/1 used for most sled engines. So if you go back to last year’s
test data and multiply each RPM step by 1.5 (and divide each torque reading by 1.5) you
will get identical torque and HP as shown here. The only difference is the precise friction
HP added by the dyno computer to compensate for the known HP loss from the very
efficient toothed belt drive. That friction HP compensator is only activated at 1.5/1, and
since the dyno was programmed improperly for 1/1 the HP lost to friction is not added
back in. Operator error! This is how I screwed up the first time we tested the DNE/ Gus
Bohne 700+ HP turbo—that time it was the opposite goof—the dyno computer was set at
1.5/1 while the monster engine was actually direct drive to the dyno. So when the engine
was spinning only 6500 RPM the dyno computer thought it was spinning 9750.
So correcting my dyno drive ratio error on last year’s F1100 we know that it was the
same as this year’s. But that 2007 version was much more powerful. It may have been a
preproduction sled (acquired early 2006 by JD Powersports for turbo experimentation).
But D&D’s Dale Roes reports that the 07 and current engines are the same, but that the
intake and exhaust were much better on the early example we had. But for now, a flat 111
HP power curve is what we had for the 2012 NY Shootout.
Compare 2013 and 2007 Cat 1100 4stroke NA engines.
EngSpd
RPM
6000
6100
6200
6300
6400
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
8500
8600
8700
8800
8900
STPPwr
CHp 13
82.8
83.4
83.0
84.9
87.2
89.1
90.9
92.5
93.6
96.1
99.7
101.3
102.4
104.8
107.2
108.1
108.5
109.9
110.7
110.5
110.5
110.7
111.4
111.5
111.1
111.1
111.0
STPTrq
Clb-ft13
72.5
71.8
70.3
70.8
71.6
72.0
72.4
72.5
72.3
73.2
74.8
75.0
74.7
75.4
76.1
75.7
75.0
75.0
74.5
73.5
72.5
71.8
71.4
70.5
69.5
68.7
67.8
STPPwr
CHp 07
85.7
88.3
91.3
94.3
95.1
96.6
98.6
99.7
101.1
102.7
104.5
107.9
109.6
111.7
115.3
116.6
118.9
120.6
121.6
123.5
125.2
126.8
127.9
128.1
130.1
131.5
132.4
131.4
132.4
132.4
STPTrq
Clb-ft07
75.1
76.1
77.3
78.6
78.1
78.1
78.1
78.5
78.2
78.2
78.4
79.8
79.9
80.3
81.8
81.6
82.2
82.3
81.9
82.1
82.2
82.2
81.9
81.1
81.3
81.3
80.8
79.3
79.1
79.1
2013 SkiDoo Etec 600
The 2013 Etec 600 (in “breakin mode) is shown with fuel flowmeters fitted and stock
airbox (not the dyno airbox with airflow meter). Note that even with a lean wideband A/F
ratio reading, BSFC is above .60 at WOT. Expect that to drop some as breakin mode is
completed.
EngSpd
RPM
6100
6200
6300
6400
STPPwr
CHp
72.4
73.7
75.0
76.9
STPTrq
Clb-ft
62.3
62.4
62.6
63.1
BSFA_B
lb/hph
0.629
0.645
0.675
0.684
FulA_B
lbs/hr
42.3
44.1
47.1
48.9
LamAF1
Ratio
14.62
14.57
14.54
14.55
AirInT
degF
65.0
65.0
65.0
65.0
ElpsTm
Secnds
0.79
1.17
1.53
1.90
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
78.3
78.7
78.5
82.3
85.6
88.2
91.0
94.1
97.1
99.6
102.4
106.1
109.3
112.4
115.1
116.5
116.5
114.8
63.3
62.6
61.5
63.6
65.1
66.2
67.3
68.6
69.9
70.7
71.7
73.3
74.6
75.7
76.5
76.5
75.6
73.5
0.742
0.761
0.790
0.777
0.770
0.763
0.747
0.734
0.722
0.710
0.688
0.672
0.662
0.636
0.616
0.616
0.603
0.606
54.0
55.7
57.6
59.4
61.2
62.5
63.2
64.2
65.2
65.7
65.5
66.2
67.2
66.4
66.0
66.7
65.3
64.6
14.55
14.45
14.20
14.06
14.03
14.02
14.03
14.08
14.17
14.24
14.26
14.15
14.05
13.94
13.92
14.08
14.24
14.35
65.0
65.0
65.0
65.0
65.0
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
65.1
2.40
2.57
2.86
3.27
3.58
3.90
4.26
4.64
4.99
5.27
5.60
5.97
6.27
6.61
6.98
7.39
7.75
8.14
2013 Yamaha Nytro
Here’s the most powerful of the 120 class sleds. This was the third test where the engine
made best torque and HP, with oil temperature up to normal. Also for those who
continue, wrongly, to think that they should get initial clutch shift at torque peak then
slide up to HP peak please look closely at this dyno test! Do we really want the Nytro
clutches to shift at 103.9 HP? Probably not. 129HP & 83.7LB/FT will outaccelerate
103.9HP & 89.5LB/FT every time.
EngSpd
RPM
6100
6200
6300
6400
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
STPPwr
CHp
103.9
104.2
106.0
108.2
110.4
112.4
114.0
115.9
117.6
119.0
120.0
120.7
121.8
123.3
124.5
125.6
126.8
127.7
STPTrq
Clb-ft
89.5
88.2
88.4
88.8
89.2
89.4
89.4
89.4
89.3
89.3
88.8
88.0
87.7
87.5
87.2
86.8
86.5
86.0
AirInT
degF
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
51.9
52.0
ElpsTm
Secnds
0.78
1.16
1.53
1.95
2.27
2.61
2.93
3.28
3.67
4.01
4.31
4.61
4.99
5.33
5.65
5.98
6.31
6.69
DenAlt
Feet
919
918
918
918
919
919
919
921
922
922
921
922
923
924
924
924
925
927
Baro_P
InHga
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
STPCor
Factor
1.039
1.039
1.038
1.038
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
7900
8000
8100
8200
8300
8400
8500
8600
8700
128.6
129.0
129.0
128.9
128.5
127.7
126.1
125.0
121.1
85.5
84.7
83.7
82.5
81.3
79.8
77.9
76.4
73.1
52.0
52.0
52.0
52.0
52.0
52.0
52.0
52.0
52.0
7.04
7.38
7.74
8.13
8.48
8.80
9.18
9.54
10.21
927
927
927
927
927
927
928
929
929
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
28.9
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
1.039
===== ==========================================================
2013 Polaris Indy 600
The retro name is excellent, but the engine HP was not! We’re used to seeing the late
model “short stroke” 600s make 120+ HP but today we could only muster just over 111
HP. So when the Indy 600 came up well short of expectations we were concerned that
something was wrong with the sled. Dyno certification is to ensure that our Shootout
sleds are proper and trypical—not too high, but not too low. Compression test with my
Harbor Freight gauge tested showed 110 psi on both cylinders. A/F ratio appeared fine, as
did fuel flow and pressure. This was late in the day—it had begun to rain very hard just
as we began testing the two Polaris’ late last Tuesday, and humidity had climbed quite
suddenly. High humidity saps some HP—but not 9 HP. The dyno correction will
compensate for humidity, but will only be fairly accurate if A/F ratio remains constant.
The ECU will compensate for air temp and barometric pressure but it has no way of
measuring water in the air (water molecules can take up lots of space otherwise occupied
by O2 molecules), so as humidity increases, A/F ratio enrichens, and HP is reduced.
And it was late in the day, but after communicating with our contacts at Polaris we failed
to get a response from them to confirm whether or not this power was proper. So this sled
was loaded back in Tom Smith’s trailer with the rest of the dyno certified stock sleds and
taken back to Tom’s storage building in Old Forge. But Fun Unlimited owner Bill Lutz
volunteered to come on Wednesday with another stock Indy 600 and if this one made the
expected 120 HP we would have made arrangement to use it instead of the first one. So
Bill and made a second 440 mile round trip to DTR, only to see it make 113.5 HP in dry
cold air (thanks to a cold front that came in overnight that, unfortunately, pushed the
warm rain up to Woodgate NY to melt the foot of snow on the Shootout track!). So what
we had was what we had. Subsequent investigation by Bill and his crew revealed new
part numbers for the Indy 600 cylinder head (said to be 2.5cc higher volume), cylinders,
exhaust pipe, muffler, and airbox top. More to come on this, in our quest to get 120+ HP
back. But for now, this is the dyno test result in cold dry air. Also it should be noted that
on this test the Polaris Digital Wrench computer indicated that peak exhaust temp was
1000F and coolant temp was 110F—both ideal numbers for achieving max power.
EngSpd
RPM
6100
6200
6300
STPPwr
CHp
67.7
68.0
69.7
STPTrq
Clb-ft
58.3
57.6
58.1
BSFA_B
lb/hph
0.600
0.615
0.574
FulA_B
lbs/hr
38.0
39.1
37.6
AirInT
degF
39.4
39.4
39.3
Air_1c
CFM
127.3
130.4
133.8
ElpsTm
Secnds
0.80
1.18
1.57
6400
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
71.6
73.1
76.0
81.8
84.5
89.7
93.4
97.4
101.0
104.2
107.2
109.4
111.3
112.7
113.4
113.4
112.8
111.6
103.1
58.7
59.1
60.5
64.1
65.3
68.3
70.1
72.0
73.6
75.0
76.1
76.6
76.9
76.9
76.3
75.4
74.1
72.4
66.0
0.597
0.639
0.699
0.688
0.712
0.698
0.703
0.694
0.704
0.666
0.656
0.639
0.625
0.615
0.595
0.586
0.570
0.545
0.612
40.1
43.7
49.6
52.8
57.3
59.6
62.5
64.3
67.4
65.5
66.0
65.3
64.3
63.6
61.2
59.6
57.9
54.8
53.6
39.3
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.4
39.5
39.5
39.5
39.5
39.5
39.6
136.7
141.2
149.3
155.6
160.1
166.5
170.1
175
178.5
182.8
185.8
188.5
190.2
191.0
191.4
191.4
191.0
190.4
187.0
1.91
2.19
2.54
2.97
3.18
3.65
3.90
4.29
4.59
4.98
5.30
5.62
5.98
6.35
6.67
7.02
7.38
7.77
8.58
150 class sleds
2013 Arctic Cat ProCross F800
Here’s the best dyno test of the Cat 800. These engines also make the best power with
1000F pipe center section temp and we were able to create that with this dyno test. The
ECU is programmed to retard ignition timing at lower exhaust temperature (which
reduces HP) to get the pipe temperature to optimal more quickly.
EngSpd
RPM
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
STPPwr
CHp
109.1
109.6
109.7
110.6
113.7
119.1
121.8
124.2
127.7
133.7
137.6
141.1
144.4
146.7
149.8
155.6
157.9
156.4
152.0
143.7
STPTrq
Clb-ft
88.1
87.2
86.0
85.4
86.5
89.3
90.1
90.6
91.9
94.9
96.3
97.5
98.5
98.8
99.6
102.2
102.4
100.2
96.2
89.8
BSFCAB
lb/hph
0.594
0.603
0.591
0.586
0.578
0.568
0.562
0.557
0.578
0.597
0.596
0.610
0.634
0.662
0.683
0.678
0.671
0.665
0.650
0.640
FulAB
lbs/hr
AirInT
degF
56.0
57.7
58.8
59.9
60.5
60.4
60.3
59.8
62.6
67.0
69.8
72.6
75.7
79.7
85.5
89.6
92.1
94.7
94.5
95.1
48.2
48.2
48.2
48.2
48.3
48.3
48.3
48.3
48.3
48.3
48.3
48.4
48.4
48.4
48.4
48.4
48.4
48.4
48.4
48.4
2013 Yamaha Apex
When we tested the first 2011 Apex with EXUP—a preproduction model with lots of
demo miles on it—we saw over 163 HP. Of course, that test article ( ) had the customary
cautionary note suggesting the preproduction might not = production. That appears to be
the case. Since then, we’ve done more than a few production EXUP Apex, all measuring
about 150 HP at peak. The 2013 is no exception. Less power than the 800 Cat and
SkiDoo, but the graphic comparison shows a broad HP plateau that assures good
performance if revs are anywhere in a 1000+ RPM band of HP at peak revs.
EngSpd
RPM
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
8500
8600
8700
8800
8900
9000
9100
9200
9300
9400
9500
9600
9700
9800
9900
10000
10100
10200
10300
10400
10500
10600
10700
10800
10900
11000
STPPwr
CHp
95.1
95.4
96.3
98.2
100.3
102.3
104.7
107.8
110.5
113.1
115.7
118.4
120.7
123.2
125.3
127.4
129.5
131.3
133.3
135.1
136.5
137.8
139.2
140.4
141.1
141.9
142.1
143.3
144.6
145.9
146.7
147.9
148.2
148.1
148.1
147.4
147.2
147.5
147.6
147.9
148.3
148.5
148.0
147.4
147.2
STPTrq
Clb-ft
75.7
74.7
74.3
74.8
75.2
75.6
76.3
77.6
78.4
79.2
80.0
80.7
81.3
81.9
82.3
82.6
82.9
83.1
83.4
83.5
83.4
83.2
83.1
82.9
82.3
81.9
81.1
80.9
80.8
80.6
80.2
80.1
79.4
78.6
77.8
76.6
75.8
75.2
74.5
74.0
73.5
72.9
72.0
71.0
70.3
AirInT
degF
54.1
54.1
54.1
54.1
54.1
54.1
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.2
54.3
54.3
54.3
54.3
54.3
54.3
54.4
54.4
54.4
54.5
54.5
54.5
54.5
54.6
54.6
54.6
54.7
54.7
54.7
54.7
54.8
54.8
54.9
54.9
Vap_P
InHg
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.33
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.34
0.35
0.35
ElpsTm
Secnds
0.85
1.19
1.56
2.02
2.37
2.69
3.01
3.39
3.71
4.04
4.38
4.69
5.04
5.43
5.75
6.12
6.39
6.72
7.08
7.38
7.67
8.06
8.41
8.79
9.11
9.32
9.64
9.98
10.30
10.54
10.95
11.22
11.60
11.97
12.29
12.63
12.95
13.27
13.62
13.96
14.29
14.61
14.94
15.29
15.62
DenAlt
Feet
1146
1146
1146
1146
1146
1147
1148
1148
1148
1149
1149
1149
1150
1152
1153
1153
1153
1153
1153
1154
1155
1156
1157
1158
1160
1160
1163
1165
1168
1171
1176
1179
1179
1181
1182
1184
1187
1191
1192
1192
1195
1198
1200
1205
1209
Baro_P
InHga
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
28.85
STPCor
Factor
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.043
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.044
1.045
1.045
2013 Polaris ProR 800
This engine, too, is the same as in previous years. As we saw when testing the Indy 600,
warm humid air would cost us some HP.
EngSpd
RPM
6100
6200
6300
6400
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
STPPwr
CHp
88.2
89.1
91.1
93.7
96.4
98.4
100.2
106.2
109.9
114.3
118.5
122.4
126.0
129.2
132.1
134.9
137.5
139.8
141.4
142.7
143.0
140.9
STPTrq
Clb-ft
75.9
75.4
76.0
76.9
77.9
78.3
78.5
82.0
83.7
85.7
87.6
89.3
90.6
91.7
92.5
93.2
93.8
94.1
94.0
93.7
92.7
90.3
BSFA_B
lb/hph
0.586
0.600
0.589
0.562
0.563
0.590
0.627
0.680
0.680
0.675
0.651
0.642
0.650
0.645
0.633
0.613
0.605
0.587
0.551
0.528
0.513
0.520
FulA_B
lbs/hr
48.0
49.6
49.8
48.8
50.4
53.8
58.2
67.0
69.3
71.6
71.6
72.9
76.0
77.3
77.5
76.7
77.2
76.0
72.1
69.8
68.0
67.8
AirInT
degF
64.6
64.6
64.6
64.7
64.7
64.7
64.7
64.8
64.8
64.9
64.9
64.9
65.0
65.0
65.1
65.1
65.2
65.2
65.3
65.3
65.4
65.5
AFRA_B
Ratio
13.33
13.17
13.32
13.81
13.63
13.00
12.36
11.22
11.10
11.04
11.28
11.30
11.05
11.07
11.19
11.44
11.49
11.91
12.35
12.76
13.10
13.12
ElpsTm
Secnds
0.78
1.2
1.52
1.89
2.28
2.57
2.79
3.28
3.54
3.91
4.25
4.59
4.93
5.27
5.59
5.92
6.29
6.62
7.02
7.32
7.66
8.08
2013 SkiDoo Etec 800
This will surely pick up more HP after “breakin” is complete. We’re planning to do a full
workup on Billy Howard’s 2013—jockeying timing about to see if we can get back to
2010.5 HP levels. But for the shootout, here is what we had this year.
EngSpd
RPM
STPPwr
CHp
6000
6100
6200
6300
6400
6500
6600
6700
85.5
86.6
88.4
91.5
99.1
102.9
106.3
111.0
STPTrq
Clb-ft
74.8
74.6
74.9
76.3
81.3
83.2
84.6
87.0
BSFA_B
lb/hph
0.806
0.811
0.792
0.781
0.735
0.726
0.708
0.698
FulA_B
lbs/hr
64.1
65.3
65.1
66.4
67.8
69.6
70.0
72.1
LamAF1
Ratio
14.04
14.00
14.02
14.07
14.19
14.20
14.20
14.22
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
116.4
121.3
125.5
129.8
136.3
139.5
140.8
142.2
145.1
148.2
150.2
150.2
148.1
144.6
140.3
UNLIMITED CLASS SLEDS
2013 Arctic Cat F1100 turbo
89.9
92.3
94.2
96.0
99.4
100.4
99.9
99.6
100.2
101.1
101.1
99.8
97.3
93.7
89.9
0.687
0.674
0.654
0.627
0.602
0.567
0.555
0.557
0.564
0.571
0.565
0.566
0.577
0.596
0.604
74.4
76.0
76.3
75.8
76.3
73.7
72.7
73.6
76.1
78.7
79.0
79.0
79.5
80.1
78.6
14.21
14.16
14.09
14.04
14.12
14.14
14.31
14.58
14.59
14.40
14.21
14.14
14.16
14.17
14.07
Dyno testing the stock F1100 turbo is a little tricky since the ECU adjusts so many
parameters (boost rise, peak boost, fuel flow, timing) based upon so many other things
(coolant temp, exhaust temp, knock, etc). So getting an optimal power curve requires
paying attention to too much data for one person. Today, Glenn Hall and Dale Roes were
great help in watching engine conditions on their Arctic Cat diagnostic software.
Beginning each test at a particular coolant temp was critical, as was watching for any
clicks of deto in the midrange that could cause timing to be pulled/ boost to drop.
Midrange deto on the dyno is not unusual because of the time spent there, as the dyno
allows revs to rise slowly in order to get accurate measurements. But in the field, revs
climb quickly to 7500 and beyond so power-robbing midrange knock is seldom an issue.
Here’s a nice example of a proper dyno test on the stock F1100 turbo with everything just
right. Note that torque rises to peak at 7500 due to the boost controller preventing boost
from rising too high at low revs preventing deto there.
EngSpd
RPM
6000
6100
6200
6300
6400
6500
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
STPPwr
CHp
129.6
127.3
129.6
132.4
133.8
135.3
138.1
141.1
142.5
144.1
148.7
154.7
158.9
162.6
171.4
177.2
178.1
176.8
175.0
174.4
171.4
167.1
STPTrq
Clb-ft
113.5
109.6
109.8
110.4
109.8
109.3
109.9
110.6
110.1
109.7
111.6
114.4
115.9
117.0
121.6
124.1
123.1
120.6
117.9
115.9
112.5
108.4
LamAF1
Ratio
12.87
12.90
12.84
12.77
12.69
12.62
12.58
12.59
12.61
12.62
12.59
12.52
12.46
12.42
12.37
12.35
12.26
12.19
12.11
12.03
11.87
11.76
ElpsTm
Secnds
0.16
0.69
1.02
1.28
1.58
1.83
2.06
2.44
2.63
2.84
3.06
3.26
3.40
3.52
3.80
4.10
4.54
4.79
5.02
5.21
5.49
5.74
DenAlt
Feet
1326
1327
1327
1328
1328
1328
1328
1326
1326
1328
1329
1328
1327
1328
1327
1328
1327
1326
1325
1327
1328
1331
Baro_P
InHga
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
AirInT
degF
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.5
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.4
56.5
56.5
Then since D&D was planning to demonstrate their $289 ECU reflash at the NY
Shootout, Glenn Hall installed a reflashed ECU and while monitoring engine conditions.
We developed this dyno test data with no other components touched—stock muffler,
same 91 octane gas.
EngSpd
RPM
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
8500
8600
STPPwr
CHp
150.7
159.3
167.8
172.6
176.8
181.2
193.9
201.8
206.7
206.1
206.2
206.1
204.5
202.3
201.6
201.1
201.0
200.8
201.1
199.6
199.3
STPTrq
Clb-ft
119.9
124.9
129.6
131.4
132.6
134.0
141.5
145.2
146.7
144.3
142.5
140.6
137.7
134.5
132.4
130.4
128.7
127.1
125.7
123.3
121.7
LamAF1
Ratio
12.58
12.43
12.13
12.11
12.12
12.14
12.24
12.38
12.52
12.58
12.53
12.40
12.26
12.13
12.04
11.95
11.90
11.87
11.85
11.80
11.75
ElpsTm
Secnds
0.40
0.79
1.21
1.43
1.59
1.73
2.08
2.37
2.67
3.01
3.35
3.66
3.89
4.13
4.32
4.53
4.72
4.92
5.14
5.35
5.65
DenAlt
Feet
1975
1970
1967
1964
1962
1961
1956
1952
1951
1949
1945
1940
1938
1934
1932
1929
1927
1925
1923
1923
1919
Baro_P
InHga
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
28.83
AirInT
degF
65.9
65.8
65.8
65.8
65.7
65.7
65.6
65.6
65.6
65.5
65.5
65.4
65.4
65.4
65.3
65.3
65.3
65.2
65.2
65.2
65.1
2013 Yamaha Nytro w/ factory authorized MPC supercharger system
The AmSnow guys thought it would be interesting to run this combo in the Unlimited
Stock class, since there’s been nothing to compare to the big Cat turbo sleds. Keith
“Woody” Wood came once again from his shop Woody’s Performance Center in
Topsham, ME with this new Nytro that was fitted with the MPC supercharger system.
Last year, I believe Yamaha sold those non-intercooled low boost SC systems to dealers
with 1/1 toothed belt drive from crank to supercharger (28 tooth crankshaft pulley, 28
tooth on the SC). But this year, since Yamaha is providing engine warranty for customers
opting for the $4399 option (plus six hours labor) they’ve dropped the boost by a few
pounds by supplying a 26 tooth crank sprocket instead of the previous year’s 28 tooth
crank sprocket.
Here’s the 2013 Nytro with the 2013 MPI supercharger system. Note that the centrifugal
supercharger increases airflow/ boost pressure as the square of engine RPM so boost and
HP peaks at the rev limiter.
EngSpd
RPM
6600
6700
STPPwr
CHp
120.9
122.1
STPTrq
Clb-ft
96.2
95.7
BoostP
psig
2.9
2.9
LamAF1
Ratio
12.11
12.13
AirInT
degF
37.3
37.3
ElpsTm
Secnds
0.71
1.18
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
8500
8600
8700
8800
8900
9000
9100
9200
123.7
126.0
128.5
130.8
133.2
135.6
138.0
140.4
142.5
144.7
147.3
149.4
151.0
152.9
154.9
156.9
158.4
160.3
162.1
163.5
165.6
167.3
168.6
170.8
172.1
95.6
95.9
96.4
96.7
97.1
97.5
98.0
98.3
98.5
98.7
99.2
99.3
99.1
99.1
99.2
99.3
99.0
99.0
99.0
98.7
98.9
98.7
98.4
98.6
98.3
3.0
3.1
3.1
3.2
3.4
3.5
3.5
3.7
3.8
3.9
4.0
4.1
4.4
4.5
4.5
4.7
4.9
5.0
5.1
5.2
5.5
5.6
5.6
5.7
5.9
12.19
12.27
12.33
12.40
12.45
12.50
12.54
12.55
12.52
12.47
12.41
12.36
12.30
12.24
12.24
12.23
12.24
12.26
12.30
12.35
12.40
12.46
12.51
12.58
12.65
37.3
37.3
37.3
37.4
37.4
37.4
37.4
37.4
37.4
37.4
37.4
37.4
37.5
37.5
37.5
37.5
37.5
37.5
37.5
37.5
37.6
37.6
37.6
37.6
37.6
1.55
1.92
2.25
2.61
2.92
3.29
3.62
3.94
4.26
4.60
4.99
5.31
5.62
5.93
6.31
6.62
6.95
7.29
7.62
7.97
8.34
8.63
8.97
9.32
9.68
As we did with the D&D boosted-up F1100 turbo, we increased the boost and
supercharger speed by installing the 2012 spec 1/1 drive from crank to SC. As we can see
this is where the “180 HP” number came from—once again occurring just before the rev
limiter.
EngSpd
RPM
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
STPPwr
CHp
127.2
128.3
130.2
132.5
134.9
137.4
139.9
142.4
144.8
147.8
150.2
152.9
155.4
157.8
159.9
STPTrq
Clb-ft
101.2
100.6
100.5
100.9
101.2
101.6
102.0
102.5
102.7
103.5
103.8
104.3
104.7
104.9
105.0
BoostP
psig
3.5
3.6
3.8
3.9
4.0
4.1
4.2
4.3
4.5
4.6
4.8
4.9
5.0
5.2
5.4
LamAF1
Ratio
12.65
12.67
12.65
12.65
12.66
12.70
12.76
12.78
12.82
12.85
12.82
12.79
12.75
12.66
12.62
AirInT
degF
46.5
46.5
46.5
46.5
46.4
46.3
46.3
46.3
46.3
46.2
46.1
46.1
46.1
46.2
46.1
ElpsTm
Secnds
0.75
1.19
1.55
1.92
2.25
2.63
2.95
3.26
3.62
3.95
4.26
4.63
4.94
5.28
5.61
8100
8200
8300
8400
8500
8600
8700
8800
8900
9000
9100
9200
162.3
164.7
166.5
168.4
170.5
172.2
174.2
175.7
176.9
178.7
180.8
182.5
105.2
105.5
105.4
105.3
105.4
105.1
105.2
104.9
104.4
104.3
104.4
104.2
5.5
5.7
5.8
5.9
6.1
6.2
6.3
6.5
6.7
6.8
7.0
7.1
12.61
12.58
12.56
12.59
12.59
12.61
12.66
12.66
12.66
12.54
12.49
12.52
46.1
46.1
46.1
46.1
46.1
46.1
46.1
46.0
46.0
45.9
46.0
45.9
5.94
6.29
6.62
6.96
7.30
7.66
7.96
8.30
8.60
8.96
9.29
9.67
Finally, Woody installed overdrive sprockets that would take boost up to 10 psi at peak—
well beyond the capability of the stock injectors to deliver adequate fuel— the stock fuel
pump is adequate but injector size is inadequate (see earlier boosted Nytro tests on this
site). With the overdrive pulleys, power climbed in a linear fashion until just above
midrange where A/F ratio began to lean out and drop HP. So going beyond 1/1 SC drive
in winter sea level air is inviting problems! With this boost level and adequate fuel flow
(from proper injector sizing, fuel volume and pressure and good tuning), it can easily be
in the 200HP range, but surely unadvisable on pump gas for even short periods of time at
this level of boost.
EngSpd
RPM
6600
6700
6800
6900
7000
7100
7200
7300
7400
7500
7600
7700
7800
7900
8000
8100
8200
8300
8400
8500
8600
8700
8800
STPPwr
CHp
132.9
134.6
137.3
139.7
142.5
145.5
148.8
151.8
155.5
159.0
163.0
166.3
169.1
172.2
175.0
177.5
179.9
182.0
183.7
185.4
187.2
188.8
190.3
STPTrq
Clb-ft
105.8
105.5
106.0
106.3
106.9
107.6
108.5
109.2
110.4
111.3
112.6
113.4
113.8
114.5
114.9
115.1
115.2
115.1
114.9
114.6
114.3
114.0
113.6
BoostP
psig
5.9
6.2
6.3
6.5
6.6
6.7
6.8
6.9
7.2
7.3
7.5
7.6
7.7
7.8
8.0
8.1
8.2
8.4
8.6
8.7
8.9
9.1
9.2
LamAF1
Ratio
10.78
10.80
10.78
10.74
10.82
10.93
11.11
11.30
11.50
11.67
11.84
11.91
11.99
12.17
12.29
12.41
12.56
12.65
12.73
12.83
12.96
13.09
13.19
AirInT
degF
48.6
48.6
48.6
48.6
48.5
48.5
48.5
48.5
48.4
48.4
48.4
48.4
48.3
48.3
48.2
48.2
48.2
48.2
48.2
48.1
48.1
48.1
48.0
ElpsTm
Secnds
0.76
1.19
1.57
1.93
2.26
2.61
2.96
3.27
3.63
3.93
4.32
4.61
4.93
5.29
5.62
5.96
6.32
6.63
6.96
7.28
7.62
7.98
8.29
8900
9000
9100
9200
9300
191.5
192.4
192.8
192.8
192.2
113.0
112.3
111.3
110.1
108.5
9.4
9.6
9.8
9.9
10.0
13.34
13.45
13.60
13.75
13.83
48.0
47.8
47.8
47.8
47.7
8.66
8.99
9.34
9.68
10.06
Here’s a graph comparing stock boost F1100 turbo with stock tune and with the $289
D&D reflash along with the Yamaha Nytro SC with 28/28 tooth pulleys and overdrive
pulleys. Note that the overdriven Nytro supercharger, even with the fuel tuner maxed out,
caused A/F ratio to lean out at high revs causing HP to tail off. More fuel is necessary to
overdrive the SC.