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3.8 jku with 488 gears with an auto

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Old Jul 16, 2013 | 12:00 PM
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Default 3.8 jku with 488 gears with an auto

Can anyone tell me what the RPMs at 60 miles an hour with 488 . Tried to search couldn't find it thanks in advance
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Old Jul 16, 2013 | 12:12 PM
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Click here…

https://www.jk-forum.com/forums/modi...17/#post211276

…scroll down until you see the charts. Charts are for 70mph but you should be able to extrapolate. Make sure you are looking at the right chart too (3.8 auto vs manual and 3.6 auto vs manual).
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Old Jul 16, 2013 | 12:12 PM
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Originally Posted by gunbo75
Can anyone tell me what the RPMs at 60 miles an hour with 488 . Tried to search couldn't find it thanks in advance
Need to know tire size and auto or stick
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Old Jul 16, 2013 | 12:25 PM
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Auto 34"toyo mt
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Old Jul 16, 2013 | 07:13 PM
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At 60mph we are at 1800 rpm that's with 37's
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Old Jul 16, 2013 | 09:21 PM
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Originally Posted by gunbo75
Auto 34"toyo mt
About 2190. Randys ring and pinion uses .7 overdrive ratio and 42re is actually .69 and it calcs to 2194 at a .7
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Old Jul 17, 2013 | 01:23 AM
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Thanks for your replys.
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Old Jul 17, 2013 | 05:47 AM
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Originally Posted by gunbo75
Thanks for your replys.
No problem sir
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Old Jul 17, 2013 | 06:02 AM
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I'm right at 2K at 60mph
2100-2200 at 65-70
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Old Jul 17, 2013 | 06:10 AM
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Will overdrive be functional when cruising or does it still kick in and out erratically?
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