Built LT1

iTrader: (3)

Anyone with an A4 made this jump? I had 3.23's and installed 3.42's. After looking at the calculator, I figure 4.10's is too much for "street use." How would the 3.73's be considering I already have a gear ratio 3.42?

95FbFormula

iTrader: (25)

The difference isnt worth the cost to do it I would stick with the 3.42 if you dont want 4.10. Just get a better stall now if you havent done so. Like around 2800 will make a world of difference.

Armyman2445

iTrader: (17)

no.....If you have 3.42 now I wouldnt waste money on 3.73's. Just not worth it. Now going to 4.11's you'll notice a differnce.

Built LT1

iTrader: (3)

I acctually had a STOCK factory converter witht the 3.42's. I now have a 2800 stall vigilante to install. I have read other posts that have said that little on no gain was had by making the jump from 3.42 to 3.73's. Just wanted the actual experiences good or bad from those who have made the swap.

Cap'n Pete

iTrader: (2)

If you want the 1/4 mile performance, then a stall and 4.10's will rock. I ran 4.10's in my A4 for 2 seasons, daily driving, with no problems! I still had the factory converter though (wished I had a stall).

But if you're only thinking of going to 3.73's from 3.42's, that's hardly worth it, although it's another step closer to 4.10's, and even with the 3.73's, you'll notice it screams a lot more on the highway.

2000blackta

iTrader: (16)

I sure as hell noticed a difference from 3.23's to 4.10's with my setup.

Fast Eddie's 02 T/A vert.

Yes there is a noticeable difference. I went from 3.42 to 3.73 with the stock converter and my T/A is faster now, off the line and on the interstate. 4.10s are tempting as hell. I'm thinking 4.10s would put me at 2600 rpms @ 70 mph which wouldn't be bad.

Built LT1

iTrader: (3)

Glad you noticed a difference in performance. I drive way over 70 and after looking at the gear ratio chart I would be spinning at too high of an rpm for a street/strip vehicle. Mathematically, me going to 3.73's must be better but to what degree? A year or so ago I received literature from "Strange engineering." They offer as an option a "lightened" ring gear set up that can reduce weight as much as six pounds. Reducing dead weight off a vehicle is one thing, but rotating weight is much more substancial.

I talked to some math geeks about what such a ratio would look like. While they had no direct answer on writing a detailed equation, they surmised the ratio should be at LEAST 10 to 1. For example, every pound of rotating weight that is reduced off the vehicle is roughly equivalent to removing 10 pounds of dead weight; because you are essentially "adding" horse power to the ground. It's a $75 option from Strange to have this done, but if it works and a net result can measured, it may not be a complete waste of time. Maybe I can dyno before and after to see if the gain is even measurable. It is an LT1 after all and any advantage is useful.

Automaticfastic

iTrader: (11)

hey builtlt1 I have a question for you. I got 3.23 in my a4. did you like the difference with the 3.42's because i want more acceleration but i wanna go 160 too! thanx for any response,

chad

BLACKBIRD8200

what do you run in the 1/4 mile? and at what rpm do you cross the traps?
just put 4.10 in mine and looking for info thanks

Cap'n Pete

iTrader: (2)

Check out www.f-body.org/gears to calculate for your gear ratio and top speeds in each gear (that is probably the most useful link ever!!!)

With my car (stock - no LT's, no cam, no stall converter) I was running pretty consistantly around ~13.0 - 13.2 @ 106 - 107 once I put in the 4.10's. I believe the motor was spinning ~5800 RPM crossing the line. With the addition of a cam and headers (power adders) and a stall to get you down the track "quicker" and "faster", I'd think the times would be low 12's between ~110 - 115 mph, so that would take the RPM's over 6000 (upwards of 6200 - 6300). That should be no problem for a cammed LS1, and it only takes a couple minutes programming to bump up your rev limiter to ~6500 RPM. Until you star running really fast in the 1/4 mile, the 4.10's are the perfect gear IMO . It only takes a few more RPM's, or maybe 27" or 28" tires to take your car deep into the 11's or faster, and still be running 4.10's .

Built LT1

iTrader: (3)

In my A4 I upgraded from 3.23's to 3.42's at the same time my first Lt1 stroker was being installed. I guess it was better than the 3.23's but the fact I use the word guess should illustrate how little it helped. I am going to 3.73's. And many people have said they noticed a significant improvement when making that jump, 3.23 to 3.73. As far as top speed, I think 160 mph is still very much possible.

Hope this answers your question.

getusum

iTrader: (42)

My buddy is running 4:10's on a4 with 3600 stall..cruise 2900rpm @70mph...monster of a 403......