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Which Gears?

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Old 10-27-2007, 11:39 PM
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Default Which Gears?

I have a 1998 Z28 A4 with 2.73 gears and want to give it a little more kick to it. This is a street car and im in high school so i dont want my gas mpg to go south to quickly. Is there a happy median, i was thinking around 3.23s. Also which brand is good, i really do not know much about this stuff. How much would this cost to put it all together.
Old 10-28-2007, 08:32 AM
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U have the same problem I do cause u have a series 2 carrier. You can buy a new carrier or you can buy Strange 3.42 thick gears. Otherwise you will have to buy 3.73 from XXXXX. I dont wanna get 18-20 on the highway. I get 28 now. You also have an Auburn carrier which is far superior to the torsen found in 99-02 cars. I would just get the Strange 3.42's from Thunder racing for $225.00, that's what I'm doing.
Old 10-28-2007, 09:49 AM
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I would go with 3.73s. That's a pretty good jump from the 2.73s that you have now, but I'm afraid that anything less will not be that noticable and then you'll be kicking yourself for not getting the smaller (numerically larger) gears.

As far as gas milege...now this may be apples to oranges here because you have an A4 and I have a M6 but I still get 26-28 mpg on the highway with 3.73s. For me in 6th gear at 70 mph I'm right around 1800 RPM.

Motive is a good brand in my opinion. That's what was in my Z/28 and that's whats in my SS.
Old 10-28-2007, 10:00 AM
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I went from 323s to Motive 373s, and love it I just have to get them setup right.
Old 10-28-2007, 10:03 AM
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When I installed my Strange 3.42 gears I dropped 1-2 mpg, city and highway. Performance increase was awesome. The difference between a 3.42 and a 3.73 is about 9% while the difference between a 2.73 and a 3.42 is about 25% (just use your Windows calculator).
Best of luck.
Old 10-28-2007, 10:25 AM
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Here's a thread with a poll that has some different opinions that might help you and give you some ideas

https://ls1tech.com/forums/gears-axles/797670-3-42-vs-3-73-gear-poll.html
Old 10-28-2007, 12:12 PM
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I have a rebuilt 10 bolt with motive performance 3.90 gears for sale less than 1300 miles since a complete overhaul. Also have the stock 3.42's for sale as well but you need a 3 series carrier. PM me if interested. Asking $450 for the rearend minus brakes + shipping.
Old 10-28-2007, 12:12 PM
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I bought a set of 2 series Motive 3.73's from a local speed shop for $208 shipped. Haven't got them installed yet, but will soon. I'm also A4 2.73's.
Old 10-28-2007, 01:49 PM
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Make sure you buy the correct gears for your "2" series carrier. Most companies will make popular gear sets for both the "3"series and the "2"series. Go with 3.73's. I ran richmonds and I think I paid 190ish for them, the install was around 275. Night and difference in the car performance wise. You WILL need a new tune ASAP to correct the speedo error or you will ring up mileage like crazy.
Old 10-28-2007, 09:04 PM
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Gear for the desired rpm through the lights. My brother's formula used to get 24 mpg with 4.10s.




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