Slart

Hi,

I have an 2002 a4 ss w/ 3.23 gears and I'd like to go to 3.42s. I called my local diff shop, they said 3.23 was as deep as I could going with a wide gear.

Reconciling that with a post I've seen here (https://ls1tech.com/forums/gears-axles/335608-2-73-3-42-swap-help.html), I assume this means I have a series-2 diff.

Do I for sure have a series-2, or is it possible I have a series-3?

I am just trying to figure out ahead of time what parts I need to swap from 3.23's to 3.42s, so any shortcuts to that answer would be surely appreciated.

Thanks,

Steve

HBHRacing

3.08 and less = 2 serise
3.23 and more = 3 serise.


Either way you can get gears to fit any serise. Hell you can get a set of 4.56's for a serise 2 if you want.

Get some 3.73's and don't listen to anything that shop has to say, ever

2001NBMZ28

IMO don't pay for a 3.23 to 3.42 swap - put your money towards a TC instead.

Race Car Driver

The performance difference between 3.23 and 3.42 is too small to justify changing r/p gears. Go to 3.73.

radio626active

Whats the main advantage from 3.42 to 3.73s if your not bringing the car to the drag strip? Im upgrading my gears from 3.23 to 3.42s. I'll go 3.73 if on the street theres a difference?

Ragtop 99

iTrader: (7)

There is NO performance gain, street or track, from that switch.
The only gain you'll get is from weight savings as your wallet will be much lighter!

3.73s will help, but buy a converter and keep the 3.23s

Slart

How can you say there is no performance gain? Clearly you are incorrect.

Perhaps you are saying it's just not worthwhile; Maybe it's not worthwhile to you, but I have higher streetability standards than you (as evidenced by your 4200 stall converter).

radio626active

My car is a street car and is never raced. I'm not bragging or being a jerk but paying the bill really isn't a issue for me as I really have no budget issues. I don't care about how much the mod costs. There has to be some advantage of going with 3.42 vs 3.23 on a street ride. I find most of you guys on here have awesome racing rides. I don't care about eta times, at all. I want a fast street car, that sounds mean, and can haul butt. My mechanic suggested I not go to 3.73 since 99.99% of my driving is highway.

RevGTO

iTrader: (12)

Do an rpm/speed chart comparison and you'll see that the differences are so minimal that the performance gains are zip. 2.73 to 3.42 = well worth it. 3.23 to 3.42 = waste of money.

radio626active

Ok what about 3.23 to 3.73?? And are 3.73s ok for alot of highway driving, not caring at all about gas mileage?

RevGTO

iTrader: (12)

What the man said ... with 3.23's, you've already got a good gearset for the LS1; I'd try a converter first and then see if you still want gears. On the highway, stock height tires, @80mph, 3.23=2400rpm, 3.73=2800rpm.

Slart

Radio is making the exact same point I'm saying. Sure 3.23->3.42 has minimal gain, but to say there is "NO" gain is plain wrong.

It's more fair to say it's not worthwhile for the money, but the thing you have to keep in mind is for a lot of people on here your f-body is your hotrod, and you're doing everything you can to make it as fast as possible, and you're willing to make compromises.

I have 2 hotrods (both run 9's), my f-body is my daily driver and it runs 13's and is nearly stock and quite reliable. I shouldn't be modifying it at all or I'll have three hotrods and no reliable cars.

My point is not everybody is trying to turn their f-body into the fastest car they can. Some of us need something to get to work with.

Fast Eddie's 02 T/A vert.

I've had 2.73, 3.42 and I now have 3.73 with an A4. With 3.73 gears my rpms @ 70 mph is 2500rpms, it's plenty liveable for me. If you spend most of your time driving @ or over 70 mph then 3.42 would be good. At 60 mph with 3.42 the drone will make you nuts, you will wish you had 3.73s Trust me on that one.

radio626active

Thanks fast eddie, thats cool to know. In AZ our speed limits are 75, I rarely keep it at 60 mph. I didnt mean to hijack his thread but Ive posted this same tread and its hard to get a answer. I dont care myself about costs, I dont care about racing, or wasting money if Im happy. I just want to know, if those 3.42s are best on the hwy, and someone answered it!!!!!

Fast Eddie's 02 T/A vert.

radio626active,
Here in the Seattle area most of my driving on the interstate is between 60 to 70 mph, very seldom do I get an opportunity to go over 70mph. Gear sets for a 10 bolt are cheap compared to other mods. Once I figure out what gears I want for sure then I can get a 9" moser or a 12 bolt. Next week I'm going to have a set of 4.10s installed then I'll know for sure. I'm curious to run the 4.10s on the highway and @ the track.

gwcrim

3.23 to 3.43 = a difference of around 190 RPMs at 70 MPH. Whereas 3.23 to 3.73 = 450 RPMs @ 70 MPH. This is based on a 1:1 transmission ratio.

I'm wrestling with the same question. The Camaro isn't my hot rod, it's my work car. Less than 200 RPMs isn't really much difference. I think I'd be disappointed unless I did the 3.73. Definitely noticeable, but not obnoxious.

texada

iTrader: (3)

get a converter and 3.73's This will keep your set up streetable than 3.23's and a converter.

KrisR

iTrader: (2)

If that's your arguement, why even bother switching the gears at all? Or, better yet, why even have a performance street car if you have 2 9-second 'hot rods'? Put whatever gears you want in, but don't argue with people that are trying to be rational.

Slart

> If that's your arguement, why even bother switching the gears at all?

Because I want it go to faster. Duh

> Or, better yet, why even have a performance street car if you have 2 9-second 'hot rods'?

Because at some point they get unreliable, and then you end up driving a slow car. Then you want to make the slow car faster so you dont lose races.

You new here or somethin?

chicane

a4 with 3.73 is perfect.

Not too much gear and you dont kill the topend either.... or mileage for that matter.

Mileage.... lol