Can I have a Sticky Please. Updated on 2/8/06 for 4.88 gears. The question of top speed, speed with 4.11, 4.56, 4.88, 5.13, 5.38 rear ends, and speed in gears keeps coming up. I figured I would compile it in one spot and then ask Roktman to make it a sticky. The data for the 4.11 is straight out of Car and Driver. I extrapolated the speeds for the other gear ratios from that data. I also dropped the Transmission Gear Ratio and MPH/1000 rpm from the other data sheets as it does not contribute to the data that most owners are interested in. Transmission 6-speed manual Final-drive ratio 4.11:1, limited slip Gear Ratio Mph/1000 rpm Max test speed I - 2.66 - 8.3 - 50 mph (6000 rpm) II - 1.78 - 12.4 - 74 mph (6000 rpm) III - 1.30 - 17.0 - 102 mph (6000 rpm) IV - 1.00 - 22.1 - 133 mph (6000 rpm) V - 0.74 - 29.8 - 153 mph (5100 rpm) VI - 0.50 - 44.2 - 153 mph (3500 rpm) Okay, some quick conversions for 4.56 gears. I - 44.5 mph @ 6000rpm II - 65.9 mph @ 6000rpm III - 90.8 mph @ 6000rpm IV - 118.4 mph @ 6000rpm V - 153 mph = 5726rpm (160.3 mph @ 6000rpm) VI - 153 mph = 3930rpm (6000rpm in sixth? To damn fast) For 4.88's I - 41.4 @ 6000rpm II - 61.3 @ 6000rpm III - 84.4 @ 6000rpm IV - 110.1 @ 6000rpm V - 149.1 @ 6000rpm VI - 220.2 @ 6000rpm For 5.13's I - 38.9 @ 6000rpm II - 57.7 @ 6000rpm III - 79.5 @ 6000rpm IV - 103.6 @ 6000rpm V - 140.3 @ 6000rpm VI - 207.2 @ 6000rpm For 5.38's I - 36.5 @ 6000rpm II - 54.1 @ 6000rpm III - 74.5 @ 6000rpm IV - 97.1 @ 6000rpm V - 131.5 @ 6000rpm VI - 194.2 @ 6000rpm
Here you go. I will double check them this weekend, but I believe they are correct. 4.10 = 1810.0 4.56 = 2055.0 4.88 = 2181.6 5.13 = 2316.8 5.38 = 2471.4
I had 4:10 and now a 4:56 axle from an 06. Its a coincidence , but 80 mph was my comparison point. 4:10 @ 80 MPH= 1600=1650 RPM 4:56 @ 80 MPH= 1850=1900 RPM This is what I measured aprox (pretty damn close though) on my speedo.
No problem. I dont know why its different, but im sure theres some mechanical reason in our trucks thats probably to blame for the variations between mathematical calculations and the in truck measurments.Im no engineer like your self, so i know you will figure it out.
this is based on gear ration not stock hp .... if you had the power with the gears you could go that fast.. but it may take another 1000 hp thats all.. so yes you can do 200 + if you have the hp with this gear ratio
Silver, So your figures say that in 5th gear with a 4.56 rear gear a stock truck should hit 160MPH. In what distance do you think? You gotta know where I'm going with this. And i noticed that the higher the gear got, the more sixth came into play at the top end.
Sorry, I have no idea as to the distance. I could probably figure it out, but I have neither the time or all the information to do so. You have to remember that the calculations are based strickly on the tire size, gearing (transmission and rearend) and rpm, with the top speed at redline, which in the case of the truck is 6000. You need to determine what top speed you want to acheive, and then gear your truck accordingly to be in the peak of your power curve at that point. If you are at the limit of your combination, you will not go any faster beyond your peak power point. May not have reached your redline of rpm, but you have reached your top speed. Make sense? I'm pretty damn tired and may not be making much sense, so if not let me know and I will try again tomorrow.
