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gearing question

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Old Jun 3, 2012 | 08:33 AM
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I'm tossing the idea about going turbo. I know my current 4.56 gears are not the best gear to build boost with. I found a set of 3.42 and 3.73 gears, both from nnbs 4x4 truck with the 8.6" rear. My current tires are 32.6" tall. About 90% of my driving is between 30-50. With the 3.42 I will be at about 1100 rpm at 49mph. I think that will be a little to low. Would 3.73 be a better option considering my tire size? Im awd so I'm not too worried about losing traction. Lol. Thanks for any help.
Also, if I do go turbo will be swapping the cam for something in the 215-218 range and getting the tc tightened to about 3k. And going with a trick stage 3 or 4.
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Old Jun 3, 2012 | 10:47 AM
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The higher the gear the better since you mostly drive it around town. A 4.56 was ideal for you until now. Since you're adding in boost, and its turbo, you'll want to load the turbo pretty good. The 3.42 would do that better than a 3.73. Even still I would go with a 3.73 because you mostly drive around town. It will help the truck get moving when you're out of boost and is a good balance for what you need. This is not taking into consideration at all your stall and cam.

Just my 3 cents
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Old Jun 3, 2012 | 11:07 PM
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Well, My truck has 32.6" tires. 3.73s with my tires should be about the same as 3.42s with a 29-30" tire. Anyone else have any input
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Old Jun 3, 2012 | 11:25 PM
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If your not racing I would go 4.10s. I had them with my turbo for a while and they seemed fine.
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Old Jun 3, 2012 | 11:27 PM
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Sure 3.42s load the turbo a little better, but lets not forget the gearing advantage entirely... Those gears on your truck would be too high. I think a set of 4.10s would do nicely for your tire size. This turbo craze and gearing up seems to have made some people forget about why people gear down in the first place. Andy, you should ask Joey how his truck feels with the 4.10s that are in it now That heavier truck is going to load the turbo just fine, so 4.10s get my vote...
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Old Jun 3, 2012 | 11:32 PM
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buy my 3.73s im selling andy
Honestly don't u want 4.56 with a procharger?
your all set-up for a pro, I would go D-1sc

Last edited by pewterliftedz; Jun 3, 2012 at 11:44 PM.
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Old Jun 3, 2012 | 11:40 PM
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Thanks. I already talked to Joey. I know hes ready to install some 3.42s. But I believe hes on a 30" tire. I already got some leave in the books for September. So maybe I can take that time to do some work on the truck lol.
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Old Jun 4, 2012 | 12:26 AM
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Don't you wanna do an 80e swap too... thats a game changer. that first gear will really load a turbo even with a shorter final drive ratio. Honestly the 4.56 wouldnt even be that far off with the HD tranny I dont think. I would say that a 4.10 would prolly be better though. Long enough first to help with the load, but short enough to keep it pulling really hard on the big end in 3rd gear.
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Old Jun 4, 2012 | 12:30 AM
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Originally Posted by AndysC3
Thanks. I already talked to Joey. I know hes ready to install some 3.42s. But I believe hes on a 30" tire. I already got some leave in the books for September. So maybe I can take that time to do some work on the truck lol.
Don't mean to change the subject, but real quick, how much does your truck put down? And can you PM me or tell me here how you made your intake?
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Old Jun 4, 2012 | 12:51 AM
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I'd say go with the 3.42 gears to take advantage of the highway rolling and spooling the turbo. You can have your tune adjusted so that it downshifts 4-3 at 10% throttle to get the sporty driving around town feeling when you're gettin on it. (or just manually leave it in 3 when around town.) Just a thought.
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