Which gear is better?
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trinity_gt
10 Year Member
Worst move ever ^ , the 4R70W will not last long shifting into O/D well short of the 1/4 mile mark !
4.10s make 3 gear good for around 110mph +or- depending on tire size and a few other things , shifting into 4 gear ( O/D ) at full blast is very bad for your 4R70W !
If you plan on a S/C or some other heavy mods go with 3.73s ,this way you can stay in 3rd for the 1/4 , because the odds are your going to trap at a higher mph the 110 !
98COBRA281
10 Year Member
id go 4.10's i always swore by 373's, except i just put 4.30's in my car and love them, its make the car feel like a real muscle car, not a heavy tank!
twogts4us
15 Year Member
I'm not familiar with the automatic transmission, there's not a way to deactivate the OD?
trinity_gt
10 Year Member
I'm not familiar with the automatic transmission, there's not a way to deactivate the OD?
I'm not sure what it is about the 4R70W that makes it unhappy with such a condition as ran260gt alleges (maybe he's thinking converter clutch lockup?) but the problem is that if you force the trans to stay in 3rd gear (1:1), then the restriction becomes engine RPM: If you've got a car going through the traps at 110MPH then with 4.10s the engine RPM would be in the range of 5800, very close to redline but technically below it.
If you went to 4.30s and still forced 3rd gear, you'd be at ~6100RPM, in excess of redline (at least for the stock internals...)
it depends is it a daily driver or what other mods do you have? i went with 3.90s and love them moe bite than the 3.73s i had and still get great crusin speed for the weekend runs. but i think that u need to decide what other mods u want if your stock and dont plan on any major power mods then 3.73 is best.
Obviously the stock cams aren't designed to make power up there, but the 05+ cars have the same crank and rods and spin that rpm safely. If that's what a person has to do to get across the traps without shifting, I wouldn't worry about rpms. Obviously if one is hitting 105+ mph across the finish line, the engine is seeing more stress from power than from turning a few hundred rpm above stock.
The 4R70W first three gears are clutch packs , the O/D is a band , this band is much weaker then a clutch pack , if you shift from 3 to 4 at full throttle you are at risk for blowing your O/D !
With the stock 4R70W you want to stay in 3rd gear in the 1/4 mile at all cost , with the 4.10s 3rd gear is only good for about 110mph depending on tire size ,so If you plan on going over 110 in the 1/4 , go with 3.73
If you plan on staying under 110 in the 1/4 , go with 4.10 !
CobraRed_96_GT
Active Member
+!, even on a built trans like mine. You have a kevlar band then you risk twisting the input shaft into licorice.
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