I searched for a topic on this but didn't find anything other than people arguing over 4.10's or 3.73's WITH a stall for the A4 cars. I was just wondering if it made ANY sense using a lower rear gear (I.E. 4.10 or lower) to overcome a low stall speed converter. It's just an idea....just getting opinions on this. If you took an A4 car and put a 4.10 or lower gear in it and didn't run a stall any higher than stock (or close to it) would you be able to launch the car anywhere near as hard as a higher stalled 3.73 geared car? If you had to drive the car in stop and go traffic every morning for long periods of time a stall might be a problem as far as heat....if the car had a street/strip set-up as far as rear suspension.....wouldn't using that low of a gear effectively do the same thing as far as putting the power to the ground when you launch the car? I know that the A4 car would probrably shift into OD before the traps.....if it was right before the traps it might not matter THAT much......what do you guys think.....If this is in the wrong section I'm sorry....I just figured the drag racing section was the proper place for this discussion....or tell me that I'm crazy discussion.....wich ever it is....thanks for ANY info in advance.....

 

The rear ratio should be selected without reference to stall speed. Your rear ratio should be such that your engine speed is above the power peak through the traps in top (non-overdrive) gear. At launch, a higher rear ratio will help a little but a higher stall will help a lot. It is best to optimize both. If you only want to change one, get a higher stall converter.

 

As far as heat goes, you can always put a BIGGER, BETTER tranny cooler for the stall. I also put higher numerical gear back (3.42)of the car to ease the work load of the tranny during city driving (tight feeling).

 

You're crazy

 

I highly doubt it. My buddy had 4.10's in his A4 SS with a stock stall. BEst he ran was 1.85 60's and 12.9's. I mangled him with a 2.73 gear and 3600 stall with a best of 1.66 60' time and 12.7 1/4 mile times. both cars were stock manifolds with a cat back and lid on DR's.


No I daily drive.. truly daily drive every day in all weather all year around with a 3600 stall from sub zero weather to 100 deg weather. I still run the stock cooler and have an Aux cooler with its own fan. Once in heavy traffic on a blazing hot day the trans hit 210 deg which is still nothing compared to stock tranny temps.


No because a Torque converter has a torque multiplication that happens when power is applied and the torque converter keep the car in the powerband all the time. Even if you had a 4.10 in the car with a stock stall it will still fall out of its power band on each shift.

actually this sticky form the trans section answers lots of questions on converters..

https://ls1tech.com/forums/automatic-transmission/728728-commonly-asked-stall-transmission-related-questions.html