Gear change

c5mike · 10-09-2009, 05:44 PM

I've seen numerous threads and posts about switching gears in an A4 so sorry if I'm

but haven't found quite the answer I was looking for with the search.

So my question is: I currently have the 3.15 gears in my car and I was the wondering the 1/4 mile improvements with going to a 3.42 or a 3.73. I know I need a stall converter but I won't be able to get one at this time. So gear change only, what am I looking to gain?

I can get a complete 3.42 diff from a friend who had it as a spare for his Z and I also know a mechanic that can put 3.73s in for a good price. So considering they would cost about the same I should go with 3.73s even though it's a DD right? What do you think I could gain 3.15 to 3.73? The 3.42 probably would only give me a tenth or a tenth and a half right? For reference my car has gone 12.82 with just a vararam and tune. Thanks for your help

pit-man · 10-09-2009, 05:52 PM

I would guess a solid 2 tenths. A 3000+ stall will make it scream !

c5mike · 10-09-2009, 06:13 PM

Do you think 3.90s would be too much gear for a daily driver? What do you think I could gain going from a 3.15 to a 3.90? I know I need a torque converter, I will be getting one soon, just don't have the extra $1000 right now. My future plans would be to make it a h/c car.

pit-man · 10-09-2009, 06:55 PM

Quote:

Originally Posted by c5mike

Do you think 3.90s would be too much gear for a daily driver? What do you think I could gain going from a 3.15 to a 3.90? I know I need a torque converter, I will be getting one soon, just don't have the extra $1000 right now. My future plans would be to make it a h/c car.

342 to 390 got me about 3 tenths once I learned to launch with it. I would think you will see about the same.

Too much gear depends on your driving. I have a 410 gear and 3600 stall in my DD Silverado. However, I don't drive more than 15 miles one way..mostly 6 mile trips at 60-65 mph.

Pitt

mitchell c · 10-10-2009, 01:54 PM

You would be wise to wait and install your T/C and gears at the same time. Unless you are doing the work yourself it's going to cost you hundreds of dollars extra to install the gears and converter separately.
You will get your biggest boost in performance from a good converter rather than just gears. Excluding NOS a T/C will give you the most bang for the buck on an A4 hands down. A Yank SS3600 and 3.73 gears would be my choice for great performance & excellent street manners .

slowtealz28 · 10-10-2009, 07:17 PM

I wouldn't do 3.73's with a daily driver and an auto. I also would only trust maybe two or three shops on the east coast to swap gears in my diff. I would never let somebody touch the diff gears that hasn't done it in a C5 before. JMO.

cyclerage23 · 10-24-2009, 10:16 AM

No need to go higher than 3.42 unless your running a much taller tire.

JON CONA · 10-24-2009, 09:33 PM

Like another member mentioned....do it all at once!!....i would wait until you had the bucks for both. Replacing the tc once the rear end is accessed is a nobrainer. I picked up 5 tenths going from a 3:15 and stock tc to a 3:42 and a yank ss3600. Good luck with your efforts......regards.....jon

Hot_Wheels · 10-24-2009, 10:07 PM

I have 3.73s and a 4000 yank converter now However I still have my old vigilante 3200 stall converter. I could bring it to MIR if your interested. I purchased it through ECS.

Its a Precision Industries (Vigilante) 9 1/2" Single Disk. When I called PI about exactly what it is, they told me it's between 2,800 - 3,200 stall, the part number stamped on it is #259415.
You can call them and tell them what type of car you have and the set-up (hp, turbo, etc) for them to tell you exactly what the stall would be for you. Their number is Toll Free: (800) 649-7866
It was in my car for about one year and only had a half dozen passes on it and is in excellent shape.

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