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Thread: 4.60 veres 4.77

  1. #1
    2,000 rpm - light wheelspin, no bog here!
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    4.60 veres 4.77

    I want to buy a set of 4.60 gears for my Naturally Aspirated NA from Maruhamotors, but they are out of them at this time and do not know when they will have them in stock. They offered me a set of 4.77 gears instead. What do You Think? I know there's not much difference but I didn't know at what point will it be going over the top. I live in Pa. and I'm more into the 0 to 60 or 0 to 100, we don't have any real long straight roads, so top end is not an issue. I'm beefing up the rear by getting an RX-7 case, a Giken 2 way Diff as well as stronger axles and billet hubs from Miatahubs, so all that is taken care of. I have put lower gears in my cars before, so this isn't my 1st rodeo, but it is my 1st Miata. Maybe I'm over thinking, but some input would help me come to a final decision. Thank You, STAY SAFE & GOD BLESS
    Last edited by CLZinn2; 03-21-2020 at 08:36 PM.

  2. #2
    2,000 rpm - light wheelspin, no bog here! Infedora's Avatar
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    This is handy if you want to understand the effect of the choice on rpm and speed. https://www.flyinmiata.com/tech/gearing.php

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    CLZinn2 (03-21-2020)

  4. #3
    3,000 rpm - starting to feel the power atlex's Avatar
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    I'm running the 4.78 kia diff ring & pinion with the Maruha 4.6 speedo sender "yellow" since that is the closest match. It's wildly over-reading speed by 10% or more. 100mph reading == 90mph GPS. Sometimes it's more like 13% off. You can do a long journey sure, it's just 5K rpm territory if you decide you want to go much over 85mph .. but this is a small 1.6 or 1.8 engine, that's nothing if the engine is correctly serviced. Just keep an eye on the temp gauge.

    These diffs and the 4.3 Torsen (which is hard to find) make for great acceleration on NAs and I can only recommend going for them, absolutely if you love revving your engine wherever possible .. do autox and don't care about exceeding 110MPH. Which I certainly don't, I find high speed stuff boring and prefer to just do 30-70mph corners. If you live in an area with speed traps I'd run a GPS to get accurate speed readings though.

    On my turbo car I run a 4.1 T2 diff with the standard 4.3 (VLSD) speed sender and it's still a few % off on the standard calibration speedo dial.
    Last edited by atlex; 03-23-2020 at 05:38 PM.

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    CLZinn2 (03-21-2020),HarryB (03-22-2020)

  6. #4
    Ninja Messiah kung fu jesus's Avatar
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    4.60 veres 4.77



    Just sayin’.

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    atlex (03-23-2020),HarryB (03-24-2020),tsingson (03-24-2020)

  8. #5
    3,000 rpm - starting to feel the power atlex's Avatar
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    When I ran a corns on the white car (aizawa one with the 4.7 diff) my friend could tell I'd driven near him, every, single, time.

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    tsingson (03-24-2020)

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