ChevyHighPerformance Posted October 5, 2003 Report Share Posted October 5, 2003 Here is a prevue of some the test results to support our upcoming install article on the Radix. Take this data as preliminary: Stock (tailgate down): 60' 2.335 sec 330' 6.614 sec 1/8 10.169 sec / 70.13 MPH 1000' 13.234 sec 1/4 15.875 sec / 85.05 MPH max HP (2nd gear) - 250 HP max TQ (2nd gear) - 271 HP With Radix (tailgate down): 60' 2.001 sec 330' 5.771 sec 1/8 8.904 sec / 79.12 MPH 1000' 11.642 sec 1/4 13.990 sec / 95.81 MPH We made about 10 runs around 3PM. Best time was 13.99 (above). The rest of the runs were from 14.001 to 14.05. We left for a while and came back for test and tune that evening. We made two more runs (best was 13.98 other was about 14.02). This was with no tailgate and no spare. The truck sat for about 1.5 hours before our first run of the evening. I really think the fluids were too cold and the drivetrain needed heated up. max HP (2nd gear) - 340 HP max TQ (2nd gear) - 345 HP timing advance - 15.5 degrees 0 knock retard Ltrims at medium cruise - 3% We measured the aerodynamic drag and rolling friction. Based on our calcualtions and measurements, the top speed is about 149 MPH drag limited in 4th gear. Link to comment Share on other sites More sharing options...
SSminneapolis Posted October 5, 2003 Report Share Posted October 5, 2003 i had my SS going 135 today on the highway...my friend was in his vette next to me on the cell...truck handles great at the high speeds...really hugs the road well... Link to comment Share on other sites More sharing options...
m396 #00-011 Posted October 5, 2003 Report Share Posted October 5, 2003 Where was this data taken. What kind of DA'? It needs a stall bad, lets get below 2.0 60'! Link to comment Share on other sites More sharing options...
dcairns Posted October 6, 2003 Report Share Posted October 6, 2003 I am curious what your tracks altitude is, too. The stock time seems rather poor, yet the supercharged time is right there with my supercharged time. I suppose it would make sense that the supercharger would tend to suffer less at altitude than Normally Apsirated. Also, what size pulley did you get? 5.3 kits should get a 3.40 pulley 6.0 HO kits should have a 3.30 pulley 6.0 Standard kits should have the 3.10 pulley Mine was "accidentally" shipped with a 3.10 Link to comment Share on other sites More sharing options...
ChevyHighPerformance Posted October 6, 2003 Author Report Share Posted October 6, 2003 3.30 inch pulley track times provided by Pittsburgh Raceway Park 0 - 60 MPH G-Tech Pro Compeition (we used the G-tech during the 1/4 mile runs) Dyno "borrowed" from a local automotive performacne engineering group. This is a proprietry design that independently measures the HP and TQ. dcairns, You might want to try this: Using Autotap (or another OBD2 package), log the RPM and the system time (computer's system clock) only. Log in this order so that the RPM and system time match up. You should be able to get 30-36 samples per second. Make a WOT run in 2nd gear (because of the room needed for 3rd gear). The data you have can be converted to speed versus time (using ratios of 1.62 for second gear, 4.10 for the rear end gear, and the tire diameter). Differentiate the speed versus time to get acceleration versus time. Convert all units to MKS (m/s, m/s^2, and kg). Multiply the follwing: HP = m x speed x acceleration / 746 Where m is the mass of your truck with you and the gas (lb/2.2). This will give you HP versus RPM. Then use: TQ = HP x 5252 / RPM This will give you torque versus RPM. This should give you well over 100 points for each curve. Do a running average and undersample to get a smoother curve if necessary. This is the HP and TQ made good at the wheels. You can add in the aerodynamic drag HP at each data point (before you calculate torque) to produce the curves that you would see on a chassis dyno that loads the vehicle down as it is loaded on the road (i.e. not a purely inertial dyno). Link to comment Share on other sites More sharing options...
papaluv Posted October 7, 2003 Report Share Posted October 7, 2003 the stock times do look low, I was at new england dragway last weekend and pulled 15.3 at 89 mph. I also tried with the brake applied and giving a lil gas but this actually stole power off the start and I finished with a 15.7 which is still faster than the 15.9 time above. I don't know the elevation in Lee, New Hampshire though. Jeff Link to comment Share on other sites More sharing options...
ChevyHighPerformance Posted October 7, 2003 Author Report Share Posted October 7, 2003 This just came to me. We dyno'd before making the original runs and we saw some knock retard (several degrees). It may be that we jumped down to a lower timing curve becasue of the PCM considered the tank to have "bad gas". Maybe the lower timing curve (i.e., lower HP) could help explain the lower original times. Link to comment Share on other sites More sharing options...
XLR8NSS Posted October 9, 2003 Report Share Posted October 9, 2003 Knock retard can easily cause those type of performance variations. Link to comment Share on other sites More sharing options...
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