Ok, what is the real deal on 3.42 gears as opposed to 3.73s in an A4.
I hear 3.42 are the best gears for a 3.8 V6 A4
I also hear that 3.73s are too high for a 3.8 V6 A4 because you will be so high in the RPMs in 4th gear when you cross the 1/4 mark.
Whats the best gear for a 3.8 A4

 

there is nothing wrong with 3.73s. 3.42s are just more ideal for street driving.
with my 3.73s i cruise 70 mph at 2500 rpms. with my old 3.42 i would cruise 70 mph just under 2000 rpms.

get the 3.73s if you drag, if you dont, then dont bother. but since i somewhat know your car-get the 3.73s. http://www.gearsareus.com

 

I think those numbers are a little off

2000RPM at 70mph

My 2.73 LT1 can't pull that off

 

i have 3.42's and i cruise at 70 at about 2800 rpm. i like them. it's even funnier when i race my friend in his a4 with 3.08's. i always get the jump off the line. i think 3.42's are good for street and possibly even track. dont lose much top end but good down low.

 

I have 3.42s and mine cruises at 2300 rpm at 70mph. This is also what the stock Y87 with 3.42s cruises at. With 3.08s I was at around 2100 rpm @70mph.

 

Using an RPM calculator for a set of 3.73's on a 4L60-E Tranny with a 26.1 inch tire diamter (stock 235/55/16's) I came up with 2,500 RPM at 71 MPH, before the lockup converter kicks in (drops it about 500 more RPM). So with a 4L60-E 1FastV6 is right on, you should be banking 2000 RPM in cruising.

KillerJello, there is something wrong - you are cruising around in 3rd gear with no overdrive!!! Get your tranny checked!

I wish people would ask before assuming that "BIG" gears kill your top end. That's such BS. Ever used a gear calculator and you'd know that even if you ran 4.56's you'd still have a max top end of 130 MPH, even though the stock computer will only let you hit 115 without editing.
Another thing I have found is that people who complain about top end, never use it. I frequently bang the govenor and I'm running the stock 3.23's.
Its really no suprise that people hear something and then run off with it though, so, I guess I have to be patient with folks and take it in stride. But suffice it to say yes, big gears do take away some of your top end, but not all. And when do most people actually get the chance to go anywhere near their top end anyway? Down in Texas we are fortunate to have some long straight away's. But anyhoo. Hey, if you think big gears kill top end, look at NASCAR. 6.00 minimum gearing and they run 180-200 MPH.

3.23 and 3.42 are not really the end all/be all of street driving - they are a start. 3.73's are what you want if you are an enthusiast. Especially with having an overdrive gear. Jeez. Back in the day we use to cruise 4.11's with only a 1:1 gear. 55 MPH at 3,000 RPM!!! Now that's hardcore.

Lastly, Josh, 3.73's are perfect - like 1FastV6 said. But you won't be crossing the finish line in 4th gear. You'll be crossing the finish line between 3,000 and 3,500 RPM in third gear. You never use the overdrive on the track. But your car isn't even fast enough to worry about that.
In fact, with stock 3.23's there is a good chance you could cross the finish line in 2nd gear!!!

If you are want max acceleration, you want to be just a hair under redline in 3rd gear at the end of the track. And for that, you'd need 4.11's or 4.56's depending on your tire setup.

 

thanks blig, i knew i was right. i look at my rpms and mph all the time. as well as oil pressure and temperature and everything else. i know my car better than i know my own girlfriend. and lately my car has been ****ing me even more than her.

 

uh oh. Sounds like trouble on the home front? tee-hee-hee.

"Never let cars get in the way of your women, and never let women get in the way of your cars"

For whatever thats worth

 

Thanks Bliggida and 1fastv6!! You guys are a great help. Now Ill look for 3.73s instead of 3.42s

 

You should go mid 15's when you're done. Possibly a low 15's run!

 

i say get the 3.73s but then your speedo will be off. fixable though.
i just cruised 60 miles checking the rpms and mph relationship.
55 mph--1900 rpms
70 mph-- 2400 rpms
75 mph-- dead on 2500 rpms
80 mph- 2800 rpms
and all of these where cruising for miles at a time.

 

the last time on the car is with just intake, im hoping with the exhaust and some 3.73 gears for a low low 15 sec run

 

I calculated engine RPM of 2152 at 70mph w/ 3.42's and 2347 @ 70mph w/ 3.73's....

EDIT: it's 2580 @70mph w/ 4.10's

EDIT AGAIN:

Since I did this in Excel and it is so easy to add more gears...

At 70mph, for the 4L60E (4th Gear = 0.70):

Gears----RPM

2.73------1718
3.08------1938
3.23------2032
3.42------2152
3.73------2347
4.10------2580
4.56------2869

 

2347/2400
whatever it takes.

 

i have 410s in my v6 and they are the perfect gear for our cars. with my TC i hoping to run low 14s- high 13s. at 65 i'm around 3000k