L31MaxExpress
I'm Awesome
I have tuned several vehicles recently and gathered a unique comparison between 3 of them. Acceleration runs made in nearly the same weather and same section of road. Different vehicles and different engine setups. The data was pretty cool and not exactly what I expected, but HP Tuners time stamps the data log so it is easy to get the acceleration times. The section of road I use for power tuning is about 1/2-mile-long section of service road that is two lanes wide. It does not have any roads or driveways that intersect into it and thus relatively safe to make a WOT hit on. Once across the gravel covered 4-way intersection the throttle is matted from a slow roll in 1st gear and away the vehicles went. I choose 25 mph as the starting point since the throttles were pinned shortly prior to that point on all 3 vehicles. The speedometer calibration is accurate on all 3 at 65 mph via GPS.
The results were surprising to me because the Suburban flat out feels like a race car. The converter hits hard and that 5.3L revs cleanly all the way to the 6,500 rpm shift points. It is loud, feels very quick for what it is and the 5.3L does a pretty good job moving the Suburban with the drivetrain combination it has. The LQ9 truck is nearly factory quiet and feels strong when the revs climb into the 3,500 rpm range and it pulls all the way to the 5,800 rpm shift points they tuned it for during the dyno tune. With the 4.10 gearing it is still a solid running truck but could definitely use a mild cam and a decent converter in the acceleration department. The 383 feels tame by comparison, it is also quiet, only revs 5,500 rpm before it shifts and that tall gearing in the 4L85E makes the acceleration feel like it is lagging behind.
1st was a 1990 Suburban 2wd with a L33 5.3L. The 5.3L was rebuilt with 0.020" over flat top pistons, milled and ported 799 heads, Texas Speed Stage 3 truck cam (216/220 @ 0.050 on a 112 LSA 0.600 lift), TBSS intake, 92mm DBC throttle body, 4" air intake with a 100mm LS3 MAF, Speed Engineering C10 long tubes and dual 2.5" exhaust with a X-pipe and Borla mufflers. Built up 4L60E transmission with a Yank SSR 3,000 rpm converter, 3.73 gears and ~27" tall P295/50R15s.
2nd was a 2005 crew cab 4x4 with a Zero-mile LQ9 swapped in place of the 5.3L. It has about 5K miles on it and was dyno tuned but had a ghost cam added that was not requested by the owner and terrible idle manners. He wanted it to run like a tuned Vortec Max truck should which for all practical purposes the truck is. I fixed the drivability problems with the tune and left the WOT stuff alone. It was not how I would have tuned it at WOT, but it put down 297 HP and right at 310 ft/lbs of torque at the wheels on the dyno. It has a 4L65E in it. 4.10 gears and 33" tall tires. The LQ9 has a new Magnaflow LQ9 Y-pipe that replaced the factory cats because one was plugged up and a Magnaflow muffler. The stock air box has K&N in it. It has an Airaid modular intake tube for a GMT900 and a GMT900 water pump and GMT900 upper hose. Those 3 things were done for aesthetics and to streamline the intake tubing. Truck has factory electric fans.
3rd was my 1997 Express with the 383 I built. 383 has 6" rods, 11:1 compression, LLoyd Elliot ported 210cc aluminum heads, Comp Custom cam (271/284 @ 0.006, 218/228 @ 0.050, on a 108 LSA and 106 ICL with 0.578" lift with the 1.7 rockers). Ported L31 truck manifold with AUS 48 lb/hr spider. Thorley Tri-Y headers into dual 3" pipes to the muffler, high flow 3" cats and dual 3" in/single 4" out muffler. 4" silicone intake ducting with a 100MM LS3 MAF. 4L85E transmission with a Performance Converters of North Texas custom built converter that flash stalls 2,850 rpm. 3.73 gears in the 10.5" full floating 14 bolt and 30.5" tall LT245/75R16s.
Raw Data from time stamps the instant the MPH reading was achieved. All time values are in seconds.
No 75-mph number from the 6.0 LQ9 truck because frankly it did not make it to 75 mph with adequate room to spare for stopping at the stop sign at the end of the test area.
5.3L--------6.0L--------383------MPH
50.421------xx-------46.655-----75
48.851----62.463----45.195-----70
47.271----60.663----43.745-----65
45.791----58.763----42.585-----60
44.491----56.685----41.275-----55
43.211----54.445----40.409-----50
42.111----53.222----39.505-----45
41.241----52.250----38.789-----40
40.491----51.315----38.039-----35
39.761----50.413----37.330-----30
39.041----49.422----36.585-----25
I know that the comparisons are apples to oranges, and I am not saying one engine is better than the other, but it was cool to see how they compared to each other in real world acceleration times. 25-75 mph is a great judge for how well a vehicle can merge onto the highway. The higher speed 40-70 is great to judge how a vehicle will pass on a 2-lane road. 25-40 mph the 5.3L Suburban edges out my 383/4L85E, then the 4L60E has to shift in the suburban. That 3.06 to 1.63 gear ratio jump is hard to overcome without alot of torque and frankly too much torque especially during the shift will blow the best built 60E to pieces. The 4L80E has a taller 1st and 2nd gear but the ratio gap is much closer. Shifting at 6,500 the 5.3Ls 1-2 shift recovery rpm is well under its peak torque RPM where the 4L80E puts the 383 right back into the meat of its torque curve. All 3 vehicles have functional TQ Management and Abuse modes still enabled.
Acceleration times from 25 mph.
5.3L-------6.0L------383-------MPH
11.380-----xx------10.070----25-75
9.810----13.041----8.610----25-70
8.230----11.241----7.160----25-65
6.750-----9.345----6.000----25-60
5.450-----7.263----4.690----25-55
4.170-----5.023----3.824----25-50
3.070-----3.800----2.920----25-45
2.200-----2.828----2.204----25-40
1.450-----1.893----1.454----25-35
0.720-----0.991----0.745----25-30
Various acceleration times and speeds
5.3L-------6.0L------383------MPH
3.450-----4.032----2.760----30-50
6.030-----8.350----5.255----30-60
9.090----12.050----7.865----30-70
4.550-----6.513----3.796----40-60
7.610----10.213----6.406----40-70
5.640-----8.018-----4.786----50-70
The results were surprising to me because the Suburban flat out feels like a race car. The converter hits hard and that 5.3L revs cleanly all the way to the 6,500 rpm shift points. It is loud, feels very quick for what it is and the 5.3L does a pretty good job moving the Suburban with the drivetrain combination it has. The LQ9 truck is nearly factory quiet and feels strong when the revs climb into the 3,500 rpm range and it pulls all the way to the 5,800 rpm shift points they tuned it for during the dyno tune. With the 4.10 gearing it is still a solid running truck but could definitely use a mild cam and a decent converter in the acceleration department. The 383 feels tame by comparison, it is also quiet, only revs 5,500 rpm before it shifts and that tall gearing in the 4L85E makes the acceleration feel like it is lagging behind.
1st was a 1990 Suburban 2wd with a L33 5.3L. The 5.3L was rebuilt with 0.020" over flat top pistons, milled and ported 799 heads, Texas Speed Stage 3 truck cam (216/220 @ 0.050 on a 112 LSA 0.600 lift), TBSS intake, 92mm DBC throttle body, 4" air intake with a 100mm LS3 MAF, Speed Engineering C10 long tubes and dual 2.5" exhaust with a X-pipe and Borla mufflers. Built up 4L60E transmission with a Yank SSR 3,000 rpm converter, 3.73 gears and ~27" tall P295/50R15s.
2nd was a 2005 crew cab 4x4 with a Zero-mile LQ9 swapped in place of the 5.3L. It has about 5K miles on it and was dyno tuned but had a ghost cam added that was not requested by the owner and terrible idle manners. He wanted it to run like a tuned Vortec Max truck should which for all practical purposes the truck is. I fixed the drivability problems with the tune and left the WOT stuff alone. It was not how I would have tuned it at WOT, but it put down 297 HP and right at 310 ft/lbs of torque at the wheels on the dyno. It has a 4L65E in it. 4.10 gears and 33" tall tires. The LQ9 has a new Magnaflow LQ9 Y-pipe that replaced the factory cats because one was plugged up and a Magnaflow muffler. The stock air box has K&N in it. It has an Airaid modular intake tube for a GMT900 and a GMT900 water pump and GMT900 upper hose. Those 3 things were done for aesthetics and to streamline the intake tubing. Truck has factory electric fans.
3rd was my 1997 Express with the 383 I built. 383 has 6" rods, 11:1 compression, LLoyd Elliot ported 210cc aluminum heads, Comp Custom cam (271/284 @ 0.006, 218/228 @ 0.050, on a 108 LSA and 106 ICL with 0.578" lift with the 1.7 rockers). Ported L31 truck manifold with AUS 48 lb/hr spider. Thorley Tri-Y headers into dual 3" pipes to the muffler, high flow 3" cats and dual 3" in/single 4" out muffler. 4" silicone intake ducting with a 100MM LS3 MAF. 4L85E transmission with a Performance Converters of North Texas custom built converter that flash stalls 2,850 rpm. 3.73 gears in the 10.5" full floating 14 bolt and 30.5" tall LT245/75R16s.
Raw Data from time stamps the instant the MPH reading was achieved. All time values are in seconds.
No 75-mph number from the 6.0 LQ9 truck because frankly it did not make it to 75 mph with adequate room to spare for stopping at the stop sign at the end of the test area.
5.3L--------6.0L--------383------MPH
50.421------xx-------46.655-----75
48.851----62.463----45.195-----70
47.271----60.663----43.745-----65
45.791----58.763----42.585-----60
44.491----56.685----41.275-----55
43.211----54.445----40.409-----50
42.111----53.222----39.505-----45
41.241----52.250----38.789-----40
40.491----51.315----38.039-----35
39.761----50.413----37.330-----30
39.041----49.422----36.585-----25
I know that the comparisons are apples to oranges, and I am not saying one engine is better than the other, but it was cool to see how they compared to each other in real world acceleration times. 25-75 mph is a great judge for how well a vehicle can merge onto the highway. The higher speed 40-70 is great to judge how a vehicle will pass on a 2-lane road. 25-40 mph the 5.3L Suburban edges out my 383/4L85E, then the 4L60E has to shift in the suburban. That 3.06 to 1.63 gear ratio jump is hard to overcome without alot of torque and frankly too much torque especially during the shift will blow the best built 60E to pieces. The 4L80E has a taller 1st and 2nd gear but the ratio gap is much closer. Shifting at 6,500 the 5.3Ls 1-2 shift recovery rpm is well under its peak torque RPM where the 4L80E puts the 383 right back into the meat of its torque curve. All 3 vehicles have functional TQ Management and Abuse modes still enabled.
Acceleration times from 25 mph.
5.3L-------6.0L------383-------MPH
11.380-----xx------10.070----25-75
9.810----13.041----8.610----25-70
8.230----11.241----7.160----25-65
6.750-----9.345----6.000----25-60
5.450-----7.263----4.690----25-55
4.170-----5.023----3.824----25-50
3.070-----3.800----2.920----25-45
2.200-----2.828----2.204----25-40
1.450-----1.893----1.454----25-35
0.720-----0.991----0.745----25-30
Various acceleration times and speeds
5.3L-------6.0L------383------MPH
3.450-----4.032----2.760----30-50
6.030-----8.350----5.255----30-60
9.090----12.050----7.865----30-70
4.550-----6.513----3.796----40-60
7.610----10.213----6.406----40-70
5.640-----8.018-----4.786----50-70
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