357

Has anybody put 3.42 gears in there C6 A6? If so, please comment if it was worth it.


Thanks

realcanuk

One of the best things you can do. Makes the car feel much lighter and much quicker without any drivability issues.

RicK T

Here are a couple prior discussions for your reading pleasure:

http://forums.corvetteforum.com/c6-t...-it-again.html

http://forums.corvetteforum.com/c6-t...in-the-a6.html

Red Sleeper

I was considering a 3.42 gear when my C6 06 A6 was stock but since I added the eforce SC I figured 3.42 gears might be too steep. Now that I see you have an eforce SC and are recommending them I can't help wondering how you are maintaining traction.

Also, what gear & rpm are you in when you cross the finish line?

Thanks!

glennhl

Take a look at the individual gear ratios before you decide on the 3.42's, you are almost turning the 6 speed into a 5 speed because without drag radials 1st gear is worthless. Remember, the A6 is a different animal than the A4. An A4 was always considered stout if you put 3.73 gears behind it, and in third gear it was 1 to 1, so overall gear ratio in 3rd gear was 3.73. But even with the 2.56 stock rear end gears, the overall gear ratio in 3rd gear is 1.53 x 2.56 = 3.92! So the stout geared A4 is not as good as the stock A6. It is hard for people to think clearly when it comes to rearend ratios because they aren't used to the big underdrive the A6 has in 3rd gear. Heck, it's even an underdrive in 4th gear (1.15).

So most people will say that the car feels so much better in each gear when you have 3.42's. But someone in a stock A6 will be in 2nd gear when you are in 3rd gear, so you can't compare the 2 in the same gear, you need to compare the 2 at the same speed.

If you speak to people with 3.42's, most did not pick up any time in the 1/4 mile by going to them. If you want to go quicker in the 1/4 mile, then a good convertor is a much better investment.

Red Sleeper

I have a spread sheet I put together that compares gear ratios for all C6 Vettes. You can plug in values and see how it affects final ratios in each gear. It also provides a graph of each type of ratio.


Anyway, if anybody wants it just PM me and I will forward it on.

Don't forgot to leave your email address in the PM!!!

Gering

Thanks for the links!

realcanuk

All good points in theory. Do you have 3.42's? I only had them for a short time without a supercharger and have no track time to compare, but I can tell you without any doubt that the car feels 100 times better all around with them. With the 2.56s the car just feels heavy, and at highway speeds loafs to the point that you need to constantly kickdown just to pass someone. I assure you its a great change for a stock or near stock A6.

realcanuk

There is no question that traction is an issue in first. I don't have track times to compare without the gears but I believe my car is at, or near the top of the 1/4 mile list for an A6.. At 10.41... And that is with the stock converter and cam. This tells me they don't hurt times too much if at all. I am going to try a taller tire this year which should help things in that respect. On most runs my car would just change to 5th just before the line, but on days where I got the trans to obey my commands, I would cross in 4th, I believe around 6800 rpm.

HOXXOH

I cross the stripe around 6600 in 3rd with a 2.56 gear. Squeezing 10's at 124-126 mph with a bolt-on LS3.

One of my racing buddies has a cammed LS2 and runs a tenth quicker. He said he gained a tenth when he swapped to a 3.42 and now is peaked out in 4th.

Swapping to a 3.42 has limited advantages for measurable performance gains, but quite a few disadvantages. Gas mileage, more frequent maintenance, and drivetrain wear, to name a few.

realcanuk

As I said, I dont know the performance difference in the quarter mile. On a street car with no blower I would do that mod in a heartbeat. The car drives so much better. I dont know where you got the frequent maintance part but whatever. As far as gas mileage... for me.... that ship sailed long ago.

realcanuk

You got me really curious as I havent looked in a long time. I can't believe the 3.42s dont help track times considering my car is still the fastest A6 LS2 car on any of the current lists. There are a few LS3 cars quicker but they have cams and converters, which I don't.


Sorry to get off topic in the thread.... to the OP, do it, you wont regret it.

brodyscorvette

Measurable performance gain or not I think the swap will make the car more enjoyable to drive.

More frequent maintenance and drivetrain wear, I wouldn't lose sleep over those 'issues'...

subfloor@centurytrans

You'll knock a little over a tenth off your ET when going from 2.56 to 3.42 gears - been there, done that (twice actually)

mitchell c

Excluding NOS a good converter on an A4 or A6 is the best bang for the buck hands down.

OBSSSD

Most people would consider that a terrible ROI...

And I would question whether or not there is any gain with a good TC - most people say no and that has been my experience.

subfloor@centurytrans

You don't think anywhere from 2-6 tenths isn't a good gain? This is a joke, right?

HOXXOH

I wouldn't even think about comparing an A6 blower car to any NA car, regardless of the gearset. Assuming the OP never hits the track, the only thing that matters is perception. If he's willing to pay for how it feels, then gears are OK. For measurable gains, a converter is the best/$.

Regarding A6 comparisons: Take another look in the LS2 and LS3 bolton lists, since the OP is headed down the bolton path. The quickest three LS2 A6 cars have 2.56, 3.42, and 2.56 gears in that order. The respective LS3 cars have a 2.56, a 2.73 and a 3.15. They all have a converter.

el es tu

Quick chart I put together of the various rear end gears and how they affect the final drive

realcanuk

I have to respectfully disagree with some of this.
Firstly, I am not comparing blower to N/A cars. Actually, if the op had a blower I would probably say to spend the money elsewhere for sure.
Assuming the op never hits the track, and the car is stock or near stock, then I think you have it totally opposite. The gears will make the car feel better, more fun to drive and probably effect reliability less than a converter might. I had the gears before then blower, with the car otherwise near stock, and I honestly couldnt believe I didnt do it earlier. So much more enjoyable at every level on the street, from launch to highway.
Also notice that a very high percent of cars near the top of the fast lists (blower or N/A) have gear changes of some level.