twinturbo496

iTrader: (2)

I have looked at lots of A4 combinations listed on this forum, in general it looks like the following is typical:

3500-3800# cars
450-550 hp
27-28" tall tires
125-130 trap speed
Most are geared with 3.73 or 4.10, but a few are running 3.42

Assuming 27.5" tires & 125 mph trap speed:

3.42 rear = 5200 rpm in Drive, 3650 in OD
3.73 rear = 5700 rpm in Drive, 4000 in OD
4.10 rear = 6250 rpm in Drive, 4400 in OD

So, I assume that every combination I looked at is just running the car out in 3rd gear? Am I wrong on this?

Any 10 sec A4 cars running a 4.8x rear gear and running out in 4th?

hardcore

iTrader: (2)

Well I went from a 3.91 back to old 3.46 cause I was running out of RPM with a 25.5 tire

Nimitz87

iTrader: (17)

I have never heard of anyone running it out in 4th....why do you want to do that?

Chad

twinturbo496

iTrader: (2)

I am going to install 4.84 gears and give it a try, my 4L80e has a higher 1st and less OD, so we will see what happens.

2ktransam

iTrader: (12)

You also have to factor in converter slip. I run my car through in 3rd with 3.73 gears and a 4k stall. I trap 128 and cross the line at 6,900 rpms with a 26 inch tall tire. The converter slip on my car is about 500-700 rpms.

tals7

i run a 4l85e.i have 4.10 gears and 28 inch tires.i go thru traps at like 6800ish off the bottle.this is with converter locked.i have hit od before car still flys but not how normaly run it.

JFM-jr

iTrader: (23)

I trapped 131 with a 4.11 on a 28 with a 4800 rpm converter going thru at 7200. Shifting into OD will be pretty tough on that tranny as it's not really designed as an acceleration gear. If your running a power adder and want some insurance upstairs go with a multi disc clutched converter. Circle D makes a nice piece that you can lockup at WOT in 3rd gear and will live a long life.

twinturbo496

iTrader: (2)

My hot rod doesn't like to rev past 7000. It is at 11.05 and I would like to get a 10 sec run out of it. If it stops raining one more time this year I may get a chance to test this setup out.

silverz28camaro

iTrader: (20)

shifting into OD with a deep gear is a bad idea.the purpose of od if for mileage, not a racing gear. If you were to run 4.84 gear and have more than 450 to the tire 1st gear will be useless, you may as well run a powerglide and a 4.10 gear, pros will be alot less weight and less hp drain and the car will hook better and be more consistent.

If you want to keep the 4l80 I would run a 4.10 gear with 28 tire, 3.90 with a 27 tire and a 3.73 gear with a 26 tire.

There are many combinations out there that work, but there is a reason why most stay around 3.42-4.30

Mine is 3.73 with a 255/60-16 tire running 6,500 @ 123mph with a 3600 converter, keep stall speed in mind to, and weather or not you are going to lock the converter.

twinturbo496

iTrader: (2)

Ran again last night, 10.6@127 in third with 3.50 gears & 28x10.5 slicks @ 12 PSI.

Then 2 runs short shifting around 4000 rpm: 10.8 @ 123 in OD, crossing the line just above 4000 rpm.

No point in this thread any more. Every response basically said the same thing: OD isn't for the track. I think comments are based on the gear ratios in a 700R4/4L60E, and I already have the 4l80e & 4.86 gears, so I am going to see what happens, hopefully it won't rain this weekend.

Thanks for everyone's input.

silverz28camaro

iTrader: (20)

what was your 60'? 1.50?

twinturbo496

iTrader: (2)

I haven't tried to launch the way a normal stalled auto does. I just let the car idle until the last yellow is on, then floor it. Probably not the best method, but I am not really a very good driver.

Car 845F

1.588
1.521
1.585
1.614

twinturbo496

iTrader: (2)

I should probably apologize for posting here if this section is only for LS engine cars, I just wanted input from people who really punish A4 transmissions, all of the hot rods with an A4 just have a 700R4 with a stock 350's, and never really run hard on the track.

silverz28camaro

iTrader: (20)

The best way to launch the 4l60e is to leave at idle, it will flash the converter and hit harder. A local guy was running 12.7 all night with a 1.8 60 brake stalling it, i told him to try to leave at idle cause thats where all of my best passes come from. his next run was his new best of 12.4 with a 1.7 60' same mph.

ZTwentyAteU

iTrader: (12)

I know this is an a4 thread, but my th350 with a 4.86 geared 9in runs through the 1/4 at 121 @ right around 7000-7100 on a 28 tire.

I cant remember what my other car did on the 4l60, but it was about 5-5500 in 3rd @ 123mph with a 3.23 and a 255/50 drag radial. don't know that size.

Just FYI, WOT shifts into OD really beats on those transmissions hard, and unless you are making a crapload of power to pull that OD gear, its a waste. If your making enough power to pull OD hard, it gonna make it a few passes and scatter

FASTFATBOY

iTrader: (23)

Not true, mine leaves MUCH harder stalled to the max on the footbrake. Depends on the converter here.

I have a 4.11 gear, 28 inch drag radial. I go through at 6600-6800 depending on the DA.

boostedbuford

3600 stall, 28in tall tire, 3.73's times in sig.

bills98ta

iTrader: (14)

I'm running the 4l60e with a 4600 stall, 4.10 gears, 28" tires... I have to launch at idle, to flash the convertor. If I bring the rpm's up ( 3500 ) it will most likely spin the tires.
My best ET, two weekends ago was a 1.36 60" / 10.59 @ 126mph at 7100 rpm...
I'm thinking of going with the 3.90 gears... Have a 200 shot 2'nd stage that I can't use...

WHPLASH

iTrader: (22)

I just run the stock 10-bolt with 3.23's. They are unbreakable!!!

odarabla

iTrader: (1)

I hit the 10 second mark and didn't hit 125mph. I ran a 10.996@122.43mph on a stock bottom end 346ci H/C/I car weighing in a 3600lbs with me in it! I have a PTC 4400rpm stall converter in the car. My 60ft was 1.492 1/8 mile was 6.98. My rear gear is a 4.11 and I am passing the gate at around 6000-6200rpm on 28" tall tires. My 1-2 and 2-3 shifts are at 6800rpm with the red line being set at 7200rpm. If I put a 4.56 rear gear I could shave a few 10ths off but not worth the trouble. I am in the process of knocking the weight down on the car to run 10.50's on the motor with this same setup!!