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Old May 28, 2005 | 09:21 AM
  #31  
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alright, i checked it out, and with my 4:10's, and a 295 tire, at 6,000 rpm in OD, i would be doing....... 170mph...give or take a few mph.

oh, and my top end is still all there, pulls to 150 fast
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Old May 28, 2005 | 12:16 PM
  #32  
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what kind of 1/4 mile advantage are we talking going from 3.73 to 4.10?
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Old May 28, 2005 | 12:28 PM
  #33  
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Originally Posted by bourbeaugmcx
alright, i checked it out, and with my 4:10's, and a 295 tire, at 6,000 rpm in OD, i would be doing....... 170mph...give or take a few mph.

oh, and my top end is still all there, pulls to 150 fast

295 is the width, what the overall height?

I have 4.10's and nitto drag radials (28.8 tall)and max out about estimating 135 in OD, 120 speedo burried for about 10 seconds
6000 grand


I don't have a supercharger though,

4.10s and a 3000 stall with 28" tall nitto drag radials is very very fun on the street.
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Old May 29, 2005 | 09:02 AM
  #34  
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295/45/18........i got the 170 mph figure from a top speed calc., the 4l60 od gear ratio is something like .7
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Old May 30, 2005 | 11:53 PM
  #35  
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Iknow people run out of gear if you go too tall. A buddy of mine ran 13.3 with 4.56 and 12.7 with 3.73. But he had to shut the motor off at 7000 with no overdrive. Also he has small od tires in a '69 Camarro. I know 12second5.3, and dont think running out of gear is a problem for him to worry about. I just don't know how much of an advantage it will give him over the 3.90's he was running. I know they will help, but is it really worth it?
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Old May 31, 2005 | 09:59 AM
  #36  
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yes, you can overgear a supercharged setup. it takes a pretty short tire to do that though. if you're running the common 31.5's i'd recomend no less than a 4.10. you will likely have to do some retuning though or you'll experience some considerable milage loss. the main issue with getting any kind of milage with that kind of gear is driving speed. if you run 80+ highway speeds alot i'd recomend a 3.42 or 3.73 gear. if you run 50-70 alot the 4.10 won't be too big a deal. for performance i'd recomend the 4.10 either way. you won't be running out 3rd even with the 4.10.
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Old May 31, 2005 | 11:24 AM
  #37  
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Thanks guys for all the replies. I'm not too worried about running out of third in the 1/4 b/c I can always move up to a 27" or 28" tire if needed.(would help with traction also) I was more worried about what would happen driving around town at about 2,000 rpm's or interstate between 2000 and 3000. Would the higher rpm be making constant boost? Would that mess with the blower or kill mpg?
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Old May 31, 2005 | 12:07 PM
  #38  
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The sweet spot as far as gas efficiency for our motors is 1800-2000 RPM's. When the motor is turning at that speed, you get max MPG; when you go higher or lower, your mileage will decrease.

With my 3.73's and a 32" tire, I was at my sweet spot at 75 MPH. Now, with 4.10's, I have lost between 2-4 MPG, depending on speed. The worst is when I am at 80-85 MPH (or greater), when I used to get 18 MPG. Now I only get 14-15 MPG at that speed.
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Old May 31, 2005 | 08:43 PM
  #39  
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Originally Posted by Naked AV
Knowing what I know now, I would have kept the 3.73's in and purchased a tight, higher-than-stock stall converter...say, around 2600-2800. That way, I would have the best of both worlds - boatloads of torque off the line/when downshifting (better than the 4.10's, I am sure ), and cruising RPM's at TCC lockup much more in line with the desires of my ears, foot, and wallet.

What some people don't realize is that numerically higher gears have a less effective range. Sure, they get you off the line more quickly, but you shift sooner, because you run out of gear sooner. So those same gears that get you off the line quickly, run out of steam once you are moving.

I experienced a real-world loss of freeway torque and HP when I switched to 4.10's, and it was significant. This had nothing to do with my shift points, it had to do with having less gear to work with once I was up to speed. Talk to guys with 3.42's....they might lose off the line, but ask them who owns the freeways...
All I can think is that maybe you have a broader power band with that radix and in that case maybe the shorter gears could be a problem at higher rolls. Because for me I would say the biggest benefit of the 4.10 was making 3rd gear really strong between 70-90mph. Having a 5-speed, I have a different situation but previously 3rd gear was a little too tall with the 3.73 and it took too long to get into my engine's narrow powerband. On the downside, I would say I lost about 5% overall mileage.
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