I know that a A4 with a stall is favored for drag racing because of consistency, but I have also read that a torque converter multiplies the torque down low offering an advantage over a manual. Lets just say all things being equal (the manual is launched and shifted at the same speed as the auto) does the auto have a mechanical advantage because of the multiplied torque.

may be a dumb question....

Thanks

 

The A4 is the advantage over an M6 at the dragstrip because of consistancy. An A4 WITH a stall is an advantage(in some ways) over an M6 because of the torque multiplication but also a few other reasons. First, there are very few people that can outshift an auto. A stalled auto makes this task much much harder. Also is it allows the car to stay up in it's powerband at all times, this is a big thing. Anyone with an auto will tell you when your at WOT and the car shifts the rpms drop way back down out of the powerband and then slowly climb back up into optimum range where the car really starts to pull again. The stall keeps the r's up there at all times under WOT so the car just constantly stays where it makes the most power and just pulls. An M6 is an advantage over a stock auto in this respect. The stall eliminates that advantage. Keep in mind there wouldn't be an advantage unless the M6 driver was very good. That's what I would compare it to. Also a stall allows you to raise the rpms up at a dead stop much like you would with a stick and a clutch. The advantage(in my eyes) is the way it preloads the suspension so there isn't so much "shock" to the drivetrain during a launch. An M6 is the exact opposite and breakage is more likely to occure in an M6 car. Both cars being mostly stock, this would make a huge difference. Start getting into modded drivetrains and the difference is much less significant. Sorry this is so long, but that's just a few reasons I could think of.

 

Less exploading rear ends for the a4 cars too

 

to clear something up, the M6 would absolutely have the advantage IF it could be launched and shifted even with the automatic...the reason being that while the automatic is slipping a portion of the horsepower in the interest of keeping the RPM up, the M6 is mechanically locking the motor to the tranny, allowing more efficient power transmission...


the catch here is that as was said, it's VERY VERY VERY difficult to shift a stick car as fast as an automatic. it CAN be done but an automatic shift takes no more than a couple tenths of a second. not an easy act to follow. also the launch in an M6 is particularly difficult because of the drivetrain setup.

-leave at too high an RPM? no slippage in the drivetrain to keep the wheels from spinning.
-leave at too low an RPM? no slippage means the weight of the car trying to accelerate will drag the motor and bog it.
- slip the clutch too much off the line? you just got burned by the automatic.

bottom line: you COULD beat an identically modded A4 with a stall, BUT you'd have to be an EXCELLENT driver and EVERYTHING, from your launch rpm to your clutch feather to your tires and suspension would have to be just right to get out of the hole harder.

 

I totally disagree with this statement. You're forgetting about torque multiplication.
For instance my car when it was lid, SSRA, OR Y, Loudmouth, 3.42s, and a Yank ST3500. 1.6x 60s, 12.teens, at 110mph. Throw the same mods on a stick shift car and it'll run 1.8x 60s, 12.3s-5s at 110-112. It's all in the 60.
Even after the heads/cam, bolt-ons. I run 11.5s at 118. 2 of my buds with simular steups and six speeds run 11.7-8 at 118.

 

a stick car will run faster than 1.8 60s assuming it hooks up. i made that statement based on the assumption that the tires/track are sticky enough to dump the clutch from a real high RPM off the line and not blow the tires off. side-stepping the clutch at 6000 RPM is going to provide one hell of a kick in the back (again, assuming the traction is there.)

my whole post was hypothtetical, in the real world, we all know for the most part, sticks can't run the same times as stalled autos because of the driver/traction factor. they all leave SOMETHING on the table. i was simply stating what would happen if a stick car was launched and driven to 100% potential (which isn't realistically going to happen).

 

manuals also have less parasitic powertrain loss
granted, i'd still probably take the stall if all you do is drag because it is just flat out more consistent (unless you get that crazily good m6 driver)
i just prefer the m6 for the fun factor

 

The M6 will be both faster and quicker IF it is driven with a very high degree of skill. Well beyond most of us, for sure. Even with considering the stall speed, the time averaged rpm with the 6-speed is going to be about the same and there is an additional 5%+ power loss with an auto.

Rich

 

I sure as hell hope stall is faster,I just traded my T56 for a built 4L60E with a COAN 3200 stall.
Was getting 1.78 to 1.85 60 ft off a real easy 2000 RPM launch,will be interesting to see what the 3.06 1st gear and 4.11 rear give me for launch.
Loved the 6 speed but after 2830 runs and increasing HP/TQ I figured it was best to switch before blowing up,grenaded T56s aren't worth that much.
Missed the final track day of the season so will only have answers in april !!!!!!

 

exactly what i was trying to say.

 

You can talk all the hypotheticals that you want. Tell you what, let me know when you meet one. I never have and I go to the track a lot.