ZR8000 MUFFLER TEST PHASE 2 SLP (ceramic coated), MBRP (stainless), BMP PL, BMP trail, SPEEDWERX The Kaczor bothers Darren and Jim came back to test the rest of the aftermarket mufflers this time using Jim s brand new 2014 ZR8000 for our test mule. Our plan was to test all the mufflers with the engine bone stock then install the D&D Riot kit on the engine. Today, like we did during the first session, Darren monitored my laptop with the Arctic Cat diagnostic software to observe coolant temp and signs of detonation and resulting timing retard. We would monitor sound levels with a digital sound level meter sitting on the dyno control console next to the shatterproof window between the control room and engine room. This would give us an A to B comparison of the aftermarket mufflers compared to the stock muffler. After fitting Jim s new sled with all of the dyno instrumentation we fired it up and did the first test with the hood/ pod in place. Then we removed the hood/ pod and installed the dyno pipe pressure/ temp fitting in place of the factory temperature probe. Disconnecting the factory probe from the wiring harness causes the ECU to default to 1030f where maximum timing is delivered. We duct taped the dyno airflow meter into the rectangular opening in the front of the airbox. The HP was the same as with the hood/ pod in place. STOCK MUFFLER, 20 lb 6 oz,, 4000 70 db, WOT 82 db
6700 119.1 93.4 0.606 69.9 13.24 202.2 1.4 964 6800 120.3 92.9 0.612 71.3 13.32 207.4 1.8 976 6900 121.6 92.6 0.617 72.6 13.42 212.8 1.9 982 7000 123.2 92.4 0.626 74.6 13.37 218.0 2.0 987 7100 125.0 92.5 0.642 77.6 13.19 223.6 2.1 990 7200 127.3 92.8 0.652 80.2 13.03 228.2 2.2 992 7300 131.4 94.5 0.670 85.2 12.71 236.6 2.4 1000 7400 137.8 97.8 0.673 89.7 12.42 243.4 2.4 1011 7500 143.1 100.2 0.671 92.9 12.23 248.0 2.2 1020 7600 146.9 101.5 0.668 94.9 12.13 251.5 2.2 1029 7700 150.1 102.4 0.666 96.8 12.06 254.8 2.5 1039 7800 152.8 102.9 0.664 98.2 12.02 257.8 2.6 1050 7900 154.7 102.8 0.659 98.7 12.07 260.1 2.6 1059 8000 155.1 101.8 0.657 98.6 12.18 262.3 2.5 1067 8100 153.2 99.3 0.664 98.3 12.30 264.1 2.6 1069 8200 145.0 92.9 0.699 97.9 12.36 264.4 2.5 1061 8300 127.7 80.8 0.754 93.0 11.90 241.7 2.2 1039 SPEEDWERX MUFFLER, 9 lb 7 oz, 4000 69 db, WOT 86 db 6700 115.4 90.5 0.586 65.7 13.47 193.3 2.1 918 6800 116.9 90.3 0.597 67.7 13.41 198.4 2.1 926 6900 119.3 90.8 0.615 71.3 13.27 206.6 2.3 934 7000 122.4 91.9 0.623 74.1 13.13 212.5 2.4 941 7100 125.3 92.7 0.634 77.2 12.96 218.4 2.5 946 7200 128.0 93.4 0.643 80.0 12.78 223.3 2.7 951 7300 132.4 95.2 0.658 84.5 12.51 231.0 2.9 959 7400 138.4 98.2 0.659 88.6 12.27 237.4 3.0 970 7500 143.9 100.8 0.657 91.8 12.08 242.3 3.0 978 7600 148.3 102.5 0.655 94.4 11.95 246.5 3.1 988 7700 151.6 103.4 0.653 96.2 11.89 249.9 3.2 996 7800 154.4 104.0 0.648 97.1 11.93 253.1 3.3 1008 7900 156.5 104.0 0.642 97.5 12.01 255.7 3.3 1020 8000 157.5 103.4 0.639 97.6 12.10 257.9 3.3 1030 8100 156.4 101.4 0.645 97.9 12.15 259.9 3.3 1036 8200 152.3 97.6 0.660 97.6 12.23 260.7 3.1 1034 8300 140.2 88.7 0.707 96.1 12.38 259.8 3.0 1022 MBRP MUFFLER, 6 lb 13 oz, 4000 70 db, WOT 86 db 6700 114.6 89.8 0.585 65.1 13.87 197.2 1.5 910 6800 116.0 89.6 0.598 67.2 13.78 202.4 1.7 918 6900 118.4 90.1 0.617 70.8 13.61 210.5 2.0 929
7000 121.3 91.0 0.625 73.5 13.49 216.6 2.0 937 7100 123.9 91.7 0.638 76.7 13.32 223.2 2.2 944 7200 126.6 92.4 0.649 79.7 13.12 228.4 2.3 950 7300 130.6 94.0 0.661 83.7 12.86 235.3 2.5 959 7400 138.2 98.1 0.662 88.7 12.56 243.3 2.6 975 7500 144.3 101.1 0.654 91.5 12.39 247.7 2.5 986 7600 149.0 103.0 0.651 94.0 12.25 251.5 2.6 998 7700 152.1 103.8 0.651 96.0 12.14 254.4 2.8 1007 7800 154.0 103.7 0.651 97.2 12.08 256.7 2.8 1016 7900 154.6 102.8 0.651 97.5 12.14 258.6 2.8 1025 8000 153.6 100.8 0.654 97.4 12.24 260.3 2.7 1029 8100 150.0 97.3 0.672 97.6 12.26 261.4 2.6 1028 8200 136.2 87.3 0.739 97.5 12.20 259.9 2.5 1014 8300 122.6 77.6 0.805 95.5 12.42 259.0 2.4 1000 8400 113.7 71.1 0.843 92.6 12.47 252.3 2.1 996 SLP MUFFLER, 8 lb 11 oz, 4000 72 db, WOT 88 db 6700 115.0 90.1 0.590 66.1 13.90 200.7 1.7 878 6800 116.5 90.0 0.601 68.2 13.85 206.2 1.8 889 6900 119.7 91.1 0.609 71.0 13.82 214.4 1.9 903 7000 123.3 92.5 0.610 73.2 13.75 220.1 2.0 915 7100 126.5 93.5 0.616 75.9 13.63 225.9 2.0 925 7200 129.1 94.2 0.626 78.7 13.45 231.2 2.2 933 7300 133.1 95.7 0.639 82.8 13.18 238.3 2.4 944 7400 139.1 98.7 0.644 87.2 12.87 245.1 2.4 959 7500 145.3 101.7 0.639 90.4 12.66 249.9 2.2 972 7600 150.3 103.8 0.636 93.0 12.49 253.8 2.3 984 7700 153.5 104.7 0.637 95.1 12.36 256.8 2.6 995 7800 155.3 104.6 0.638 96.3 12.32 259.2 2.7 1005 7900 156.0 103.7 0.639 96.9 12.34 261.2 2.8 1014 8000 154.8 101.7 0.646 97.3 12.39 263.2 2.8 1020 8100 147.6 95.7 0.680 97.5 12.38 263.7 2.6 1016 8200 127.8 81.8 0.772 95.7 12.46 260.5 2.3 991 8300 113.1 71.6 0.848 93.0 12.44 252.8 2.1 977 BMP TRAIL MUFFLER, 6 lb 11 oz, 4000 80 db, WOT 87 db 6700 115.2 90.3 0.589 66.0 13.69 197.3 1.6 911 6800 116.6 90.0 0.602 68.3 13.62 203.0 1.9 918 6900 119.2 90.7 0.617 71.5 13.60 212.5 2.1 930 7000 122.1 91.6 0.620 73.6 13.55 218.0 2.2 938 7100 124.8 92.3 0.626 76.0 13.45 223.2 2.3 944
7200 127.4 92.9 0.638 79.0 13.28 229.2 2.4 950 7300 130.9 94.2 0.647 82.4 13.07 235.0 2.5 958 7400 137.1 97.3 0.654 87.2 12.75 242.9 2.9 972 7500 143.7 100.6 0.648 90.5 12.55 248.0 3.3 984 7600 148.7 102.7 0.644 93.1 12.39 251.9 3.3 996 7700 152.2 103.8 0.644 95.3 12.24 255.0 3.0 1006 7800 154.4 104.0 0.643 96.5 12.21 257.3 2.9 1016 7900 155.7 103.5 0.640 96.8 12.26 259.3 2.9 1024 8000 155.4 102.0 0.643 97.0 12.33 261.4 2.9 1030 8100 152.9 99.1 0.654 97.1 12.40 263.2 2.9 1032 8200 146.5 93.8 0.677 96.2 12.53 263.4 2.7 1030 8300 132.9 84.1 0.730 94.1 12.77 262.5 2.6 1020 8400 121.7 76.1 0.749 88.4 12.62 243.7 2.4 1015 BMP POWDER LITE MUFFLER, 5 lb 0 oz, 4000 79 db, WOT 92 db 6600 114.6 91.2 0.571 63.9 13.85 193.2 1.9 886 6700 115.4 90.5 0.580 65.3 13.74 196.1 2.3 903 6800 117.1 90.4 0.593 67.7 13.60 201.2 2.2 912 6900 120.0 91.3 0.605 70.7 13.44 207.7 2.3 922 7000 123.1 92.3 0.610 73.2 13.32 213.0 2.3 932 7100 125.3 92.7 0.625 76.3 13.14 219.0 2.4 939 7200 127.5 93.0 0.634 78.8 12.97 223.2 2.5 942 7300 132.0 95.0 0.654 84.1 12.66 232.5 2.8 952 7400 137.9 97.8 0.652 87.6 12.46 238.4 3.0 962 7500 143.2 100.3 0.651 90.8 12.28 243.7 3.3 972 7600 147.5 101.9 0.650 93.3 12.17 248.1 3.4 980 7700 151.1 103.0 0.647 95.2 12.11 251.9 3.3 991 7800 153.7 103.5 0.644 96.3 12.12 254.9 3.2 1001 7900 155.2 103.2 0.640 96.6 12.19 257.4 3.2 1009 8000 155.0 101.7 0.641 96.7 12.30 259.8 3.1 1016 8100 152.9 99.1 0.650 96.7 12.38 261.5 3.0 1018 8200 145.8 93.4 0.679 96.2 12.45 261.6 2.9 1014 8300 129.5 81.9 0.746 93.8 12.67 259.6 2.7 1002 8400 118.6 74.2 0.752 86.6 12.47 235.9 2.4 999
After comparing the mufflers on the bone stock ZR8000, Jim and Darren installed the 2 degree offset timing key, higher flowing Y pipe, LCR head (tighter squish clearance, lower compression ratio), and adjustable muffler included in the D&D Riot kit. We made best power with the adjustable outlet in the tightest position. How can we make more HP with less compression? The Cat deto protection is very sensitive one or two light clicks on the dyno or in the field will result in timing being retarded, protecting the engine and reducing HP. D&D s LCR head s reduced compression head allows for advanced timing to bring back the peak cylinder pressure at the correct time ATC without deto. And remember whatever air/fuel mixture is packed into an oversize squish band under compression will burn eventually, but too late to add to HP. Tightening the squish band squeezes more of that wasted mixture at high velocity into the combustion chamber allowing it to burn at the correct time, adding to HP. And, the increased velocity has the added benefit of increasing turbulence in the combustion chamber, which is said to cause the A/F mixture to burn more quickly which can reduce the time necessary to create maximum combustion chamber pressure. It s the same effect as increasing ignition timing, but without the penalty of adding burn time to heat the combustion chamber surfaces. So with the D&D Riot kit the combo of the tighter squish band and 2 degree key may have the net effect on peak combustion chamber pressure as, say, a 3.5 degree key, but with less heat being absorbed by the combustion chamber surfaces which can = less chance of deto. Balancing compression ratio, squish design and clearance, and ignition timing to create maximum torque on a given octane can result in optimal performance. D&D RIOT KIT WITH STOCK PIPE 6700 118.8 93.1 0.569 65.5 13.51 193.4 1.7 905 6800 120.3 92.9 0.589 68.7 13.32 199.9 2.1 920 6900 123.1 93.7 0.598 71.4 13.22 206.1 2.3 930 7000 126.0 94.5 0.603 73.5 13.18 211.8 2.5 936 7100 128.5 95.0 0.614 76.4 13.08 218.3 2.6 942 7200 131.0 95.5 0.623 79.0 12.91 222.9 2.7 946 7300 135.1 97.2 0.636 83.2 12.65 229.9 2.8 954 7400 141.9 100.7 0.636 87.4 12.41 237.0 3.2 966 7500 147.8 103.5 0.629 90.0 12.30 241.8 3.6 974 7600 152.8 105.6 0.623 92.2 12.20 245.8 3.7 983 7700 157.7 107.6 0.621 94.9 12.06 250.1 3.4 997 7800 160.9 108.3 0.618 96.3 12.03 253.2 3.3 1009 7900 162.3 107.9 0.615 96.6 12.10 255.4 3.3 1018 8000 161.6 106.1 0.621 97.2 12.15 257.9 3.3 1027 8100 159.3 103.3 0.633 97.7 12.16 259.4 3.2 1030 8200 141.1 90.4 0.714 97.4 12.01 255.5 2.9 1008 8300 126.3 79.9 0.763 93.1 11.49 233.8 2.6 990
Next Jim and Darren installed their D&D single pipe on the Riot kitted engine. They had to add fuel with their new Boondocker fuel controller, which now has more precise steps adds and subtracts fuel based upon % of fuel flow which is the ideal way to tune EFI very much like the DynoJet Power Commanders do. Then, they installed the full Jaws exhaust system Y pipe with larger outlet and donut, single pipe and muffler. After creating good fuel maps for both systems, the full Jaws setup matched the D&D full system HP within a few tenths of a HP, but Jaws backpressure was lower. Jim installed the Speedwerx muffler on the Jaws pipe, and backpressure increased along with HP. The Jaws/ Speedwerx combo had a slight high RPM HP advantage but the D&D had better midrange torque and HP as the Riot graph comparing stock, D&D, and Jaws/ Speedwerx combo indicates. Jim and Darren plan to run their identical ZR8000s with Riot kits one will have the D&D full exhaust with better midrange TQ and HP, and the other will have the higher RPM Jaws Ypipe and single pipe and Speedwerx muffler with the stock muffler insulation fitted to it to fool the SS (Schutzstaffel) Trail Police who like to lift hoods even on quiet sleds and write $200 tickets for non OEM muffler. RIOT KIT WITH D&D SINGLE PIPE 6600 110.3 87.8 0.590 63.4 13.25 183.7 1.7 924 6700 111.3 87.2 0.595 64.6 13.35 188.3 1.8 933 6800 112.8 87.1 0.607 66.7 13.35 194.6 2.0 936
6900 115.8 88.2 0.620 69.9 13.33 203.5 2.3 938 7000 120.8 90.6 0.621 73.1 13.28 212.0 2.3 941 7100 124.4 92.0 0.628 76.1 13.14 218.3 2.4 944 7200 127.8 93.2 0.631 78.5 12.99 222.8 2.6 948 7300 135.2 97.2 0.638 83.9 12.67 232.4 2.9 962 7400 142.7 101.3 0.627 87.0 12.50 237.7 3.0 975 7500 152.4 106.7 0.612 90.8 12.31 244.0 3.1 994 7600 158.6 109.6 0.604 93.2 12.20 248.2 3.3 1009 7700 162.6 110.9 0.599 94.7 12.15 251.4 3.4 1020 7800 166.0 111.8 0.593 95.7 12.21 255.3 3.3 1033 7900 167.6 111.4 0.589 96.1 12.33 258.7 3.4 1040 8000 156.2 102.6 0.636 96.5 12.23 257.7 3.2 1026 8100 133.0 86.2 0.733 94.7 11.57 239.3 2.7 994 RIOT KIT WITH JAWS Y PIPE, PIPE AND SPEEDWERX MUFFLER 6700 112.5 88.2 0.573 62.3 13.38 182.1 1.9 900 6800 114.0 88.0 0.587 64.8 13.19 186.8 2.0 912 6900 116.3 88.6 0.602 67.8 12.99 192.4 2.1 926 7000 119.7 89.8 0.612 70.9 12.83 198.9 2.2 939 7100 122.2 90.4 0.623 73.7 12.68 204.1 2.3 944 7200 124.7 91.0 0.635 76.6 12.52 209.5 2.5 948 7300 129.2 93.0 0.647 80.9 12.33 217.8 2.7 958 7400 135.8 96.4 0.644 84.7 12.17 225.1 2.9 973 7500 141.6 99.1 0.643 88.1 12.03 231.4 3.0 986 7600 145.7 100.7 0.641 90.2 11.95 235.6 3.1 995 7700 150.6 102.7 0.637 92.8 11.85 240.2 3.2 1006 7800 156.1 105.1 0.630 95.1 11.79 245.0 3.2 1020 7900 159.9 106.3 0.622 96.2 11.84 248.8 3.3 1029 8000 163.9 107.6 0.616 97.6 11.90 253.8 3.4 1041 8100 167.4 108.5 0.614 99.2 11.92 258.4 3.4 1052 8200 169.5 108.6 0.614 100.6 11.99 263.3 3.4 1061 8300 170.1 107.6 0.614 100.8 12.15 267.7 3.5 1065 8400 169.0 105.7 0.618 100.8 12.32 271.2 3.5 1068 8500 155.6 96.1 0.675 101.3 12.19 269.6 3.5 1059 Here s a graph of the HP of the three exhaust systems, with much finer resolution showing the exact shape of each curve. Sometimes recording 1,000 data points in a 10 second test provides a more meaningful picture of an engine s HP curve.