before everyone starts shouting chants of "noob, noob!" at me, let me explain the basis for this post. i always see the a4 guys talking about these parts and since i have an m6 i never really bothered learning about them. but now im kinda curious. so what does each one do exactly and how does it help make the car faster?

 

The reason not many people have posted is because of your thread name...

A Torque Converter IS a stall...

Go to the Automatic Transmission Forum to get more info on stalls, and what they do...
In short, they make your car alot faster, and its a great mod for any automatic (A4).

 

yeah think you accidently put this in the wrong forum.. im sure a mod will move it shortly.

 

I will move it.

 

ah ha! that explains why i couldnt find it back in the external engine forum....yea i've never been to the auto forum since i have a manual. the only reason im asking is because i saw in some other posts that people said with a stall/tc an auto car would beat a manual. so im still trying to figure out what exactly they/it does. i searched the stickys up top but no info on them.

 

Ok I got a few minutes to kill so here goes.

Lets look at my particular converter as an example. It's a 3500 stall with a 2.5 STR and a 4800 rpm shift extension. Confused? Ok here is what all that means.

3500 is the rpm my stall will flash to. So when I punch the gas from a dig or slow roll my rpm's immediately jump to 3500 and I climb from there.

4800 is my shift extension so when my transmission shifts it'll only drop to 4800 rpm's and climbs up from that point. This is only benificial if the motor makes a lot of power up high in the rpm's so good thing I have a LS1

So from a dig in a 1/4 mile I flash to 3500 rpm's out of the gate and climb to 6000 rpm's where I shift into second at about 40 mph. I then drop to 4800 rpm's and climb back to 6000 rpm's where I shift to third at about 80 MPH. I drop again to 4800 and cross the traps at about 109 MPH.

STR stands for Stall Torque Ratio. Basically it multiplies the torque during a launch so the higher the STR the harder my car launches. This makes for one hell of a fun launch at the track with sticky tires but can be frustrating on the street when you spin.

The higher the STR the less effiecient it is and thus it'll eat more HP through the drivetrain. So basically auto guys want to find a happy medium which 2.2-2.6 STR seems to be.

So when I line up with a M6 with equal power at the track my advantage is at the launch. I will pull them hard from the hole and mount a decent 330' lead. Then they spend the rest of the track trying to reel me in. On the street however the M6 still has the advantage since digs are spin city and roll races still favor the transmission with the better gears and less drivetrain loss. But then again you can factor in the "driver mod" and still see a lot of autos win on the street to kids who think they shift like Evan Smith but in reality they granny shift and don't double clutch like they should

Sorry I couldn't resist. Hope that helped you.

 

yes thank you, it was helpful. my other question is can this thing be turned off for city driving? always running your car in the higher rpms would eat the hell outta your gas milage. perhaps the unit only activates when it senses the gas pedal is pushed past a certain point? also, you said that it gives you an advantage in the beginning of a race against manual cars but that it also eats up some extra hp through the drivetrain. so does this mean in a 1/8 race you would still have an advantage but that by the 1/4 it would be even or the m6 would have the edge?

 

My converter locks at 40 MPH. So once I hit 40 the rpm's drop to normal. Under 40 MPH and the converter is unlocked (or on as you called it) but I'm only running 1500-2000 rpm's which isn't that big of a deal. HWY mileage is unaffected by my stall. City mileage went down by probably 3-5 MPG but considering what I have gained in performance I think it's a fair trade.

Basically picture a race where the A4 jumps out with a 2 car lead by the 1/8 mile. Then picture the M6 reeling the A4 in slowly and bringing the lead to one car by the time they cross the finish line. Then picture the timeslips reading something like:

A4: 12.4 @ 108 1.7 60'
M6 12.7 @ 111 1.9 60'

This is a very normal outcome to a race with normal drivers. In most cases the A4 wins the 1/4 mile but only because the M6 ran out of track to finish reeling him in. Run this race on the street and go a half mile and you'll see the M6 pass the A4 eventually and continue to pull.

Now you can see why the A4's are better at the strip and the M6's are better on the street. But this is not to say the M6 can't rival the A4 at the track. But in order to to run with a stalled A4 they need a 12 bolt or 9" rearend, 4.10 gears, sticky tires, possibly a better clutch and one hell of a good driver. Then with a big RPM clutch dump and power shifting you can hang with the stalled auto on the launch and beat them on the second half of the track.

It's expensive and takes launching and shifting skills but it can and has been done. But autos are easier and less expensive to make fast for 1/4 mile racing.

Hope that helped you.

 

yes, it helped quite a lot. even though i have a manual i was always curious about why exactly autos put up better numbers than manuals. now i know i'll need like half a mile to catch em lol.

 

I'm an A4 guy and knew a little about converters, but not enough. This cleared some things up for me (the locked/unlocked part). Good explanation I think it's sticky material.

 

You won't need half a mile. In most cases the M6 would pass the A4 within a few hundred feet after crossing the 1/4. But remember the street does not have a burnout box or a guy with a mop putting something sticky down

We only have the advantage at the drag strip. On the street, road course, autoX and definately on the highway the advantage is all on the M6 assuming good shifting skills.

 

ill take my stalled auto over an M6 everyday from a dig on the street

 

And assuming the same or close to the same power.

 

I hear you. What a lot of people (especially the youger crowd) need to understand is being able to drive a stick and being good at racing a stick are two completely different things.

Consistency heavily favors the autos as well as the fact that no one can outshift a computer. For every great M6 driver I see at my track there are 5 that are in desperate need of the "driver mod". I've had manuals before but the stalled auto is my personal preference and that will never change