I really wish someone with an A6 would go to the dragstrip! I can see how some have to wait until spring but there are still some parts of the country with tracks open year round. Considering the fact that the A6 practically eliminates the dead spots of the A4, I really don't see how it could be slower in the 1/4 even if the A6 did have to shift one more time. I can guarantee that if I had bought an A6, I would have had it to the track as soon as the odo showed 500 miles. Maybe the forum should offer an award for the first A6 person to get a 1/4 mile timeslip!

Mike

 

I think the reason is most of us didn't buy our C6 with an A6 to race.

 

Mike trust me, if the track was open I would be there. I'm not doing one mod until I have baseline times. I already have dyno results now I just need the track to open.

 

From all I can gather the A6 SHIFTS AT 50/80/AND SOMEWHERE AROUND 130. That means that both would hit the traps in third. The A6 would attain it's top speed in 4th very likely as it seems the 5th and 6th are overdrive gears. With the A4 /3.15 shifting at 50 and 90 there doesn't seem to be a lot of difference at least in the quarter mile.

I would suppose that the A6 would outpreform the A4 IN THE 80 TO 120 RANGE BECAUSE THAT IS WHERE THE EXTRA GEAR REALLY COMES INTO PLAY. Here the A4 is locked/stuck in top gear[3RD] and the A6 is giving you 3rd with one more GO gear still available. But even that depends upon the ratio of 3rd gears with final drive ratios factored into the equation. I recall reading the A6 first and second gears were low but then got much ''taller''.

The lack of information regarding this is weird. You are right ---why hasn't one person in Texas, California,Florida, or any other state taken their's to a track yet?

In fact ,yesterday I spoke to someone in sales at a very dinstinguished dealership. We spoke at some lenght regarding the two trannys and when asked to compare he told me the A6 WAS SMOOTH AND THE PADDLES FUN. But when asked if it was quicker, he was unable to provide an answer.

All we have is speculation until someone provides the facts. So until I am proven wrong I will specualte that my A4 will be quicker then an A6 in the quarter----prove me wrong somebody.

I will speculate that side by side at 35 I will pull on the a6.

I will speculate that side by side at 40/50 the A6 pull on my A4. We both will downshift to second but the A6 has a lower ,shorter 2nd gear and will hit it in at higher rpm's.

I will speculate that when the A6 is shifting from 2nd to 3rd at 80 mph that my A4 will be in it's sweetspot as it rockets to the 90 mph shiftpoint---closing, catching, perhaps passing---perhaps not.

Now we are very close at 90--not sure who is ahead---I am locked in 3rd gear and the A6 is in third gear with a reserve extra gear waiting.

This is a point where I am far less sure of outcomes. I would think that the A6 WOULD PULL HERE.But then again the A6 3rd and 4th gear start to get a little tall---kind of like the first 5 liter Mustangs in 82. We have individual gear ratios coming into play with final drive ratios.

What really needs to be done is for some magazine to rent a 10 mile stretch of a 5 lane hiway and put an A4/2.73 ,an A4/315, anA6/2.56, a MN6, and a Z51 MN6 side by side. It would be interesting to see the results at the end of the quarter and then just keep theM going to their true top end. I would pay to see that. If they can find 6 lanes they could throw a C5 Z06 into the mix, 7 lanes gets a C6 Z06 a TICKET TO THE DANCE.

Think about it. Most have conceded the C5 Z06 the quarter mile. But when would the C6'S CATCH IT? Would even the lowly C6 automatics eventually reel in the C5 Z06 and pass it at 160 or 165?

I don't have the answers ---but I sure would buy the DVD if anyone could put together ''THE ULTIMATE CORVETTE CHALLENGE''.

 

True, but here's what is interesting:

A6 shift speeds: 49/84/130
A4 shift speeds (3.15 perf. axle): 53/99/161

Now, while they both go through the traps in third, the A4 has just switched to third and is lugging through the traps at a lower RPM. The A6 on the other hand, has used up most of its third gear and rolls through the traps at a higher RPM, which means the A6 should be accelerating faster.

Assuming about 110 MPH trap speeds:

A4 goes through the traps in third at about 4400 RPM
A6 goes through the traps in third at about 5500 RPM

Since the A6 is in effectively a lower gear with a higher overall drive ratio, the torque multiplication is higher and the A6 should be accelerating quite a bit quicker (about 20% quicker) from the A4's shift point to third, all the way to the end of the quarter.

As I see it, this gives the A6 a significant advantage from 99 MPH all the way to 110 when they cross the 1/4, or about the last 2-3 seconds of the quarter.

Mike

 

Mike I cannot argue with your logic here. I would suspect the same thing. My a4 when simply left in drive does shift itself at 50 and 90--I don't hit 99. I believe the a4 shift points for a 2.73 are about 55 and 100--at least that was what they were in my old ls1.

But regardless I would sure love to see some times so we would know what they can do. We have several a4's in the 12.7/12.8 and 12.9 range and one in the 12.5. That extra gear seems like a bonus for the a6 from 80 on up but until a couple get theirs to a track all I can do is SPECULATE.

Come on guys--whether you bought them to race them or not--take a shot and let us know. I don't race either but I thouroughly enjoyed reliving my youth and making three passes.I want the A6 to be performer I envisioned when they announced it so I can justify the outlandish cost for an upgrade.

 

Here is a graph of the torque multiplication (final drive ratio) versus speed for both trannies. Everything else being equal (like parasitic losses), acceleration should follow similar curves since acceleration is directly proportional to final gear ratio. The only thing I didn't factor in is the torque curve but since it is pretty flat for most of the range on the LS2, it shouldn't alter the overall picture too much.

Given the above graph, it looks like the only real advantage (on paper) of the A4 gearing is between about 85 and 100 MPH and a very slight advantage between about 130 and 160. For the 1/4 mile, at least on paper, the A6 should put down more torque overall in the 1/4. Now, the speeds listed in this graph can be shifted down by as much as 10% due to torque converter slippage (as you noted with your 50 and 90 readings), but like the torque curve of the LS2, shouldn't change the overall picture.

Also, if you are watching your speedometer to see when shifts occur, don't! Your speedometer is a good 5 MPH or more behind the actual speed when you are accelerating that fast due to the buffering that is done to prevent needle bounce.

Mike

 

Mike thanks for the graph. I won't mess with an A6 unless we are doing 130.

 

I don't know... I'd like to see a rolling start from 70 MPH. I bet at that speed, the A6 might be too close to the shift point and would refuse to downshift so in a quick burst from say 70-100, you should be able to take the A6.

Mike

 

Same here, plus I'm only at 220 miles so far LOL.

 

True, but some us did.
I would love to be the first guy out there with a timeslip...regardless I do hope to be one of the quickest stock.

 

Mikes, nice work.

In addition, the A6 will have another small advantage over the A4. The closer gear ratios allow the engine to stay closer to the highest part of the power curve.

 

70 to 100 IS ''De sweet spot''

 

I'd love to go to the track. Carlsbad Raceway is only about 30 min. from me. The problem is I've never "formally" drag raced. I would feel stupid, not knowing the procedures. If someone in San Diego wants to go up with me and show me the ropes, I'd like to to it. Or you can drag my car and I could learn that way.

 

Shooter, save your money for a Z06. The A4 and A6 are too close to make much of a difference.

 

Try Qualcomm Stadium. My son takes his C5 there every once and a while. You need a helmet and it is police sanctioned. I think he pays around $20 and you can have as many runs as you like. There are all kinds of cars and it is just 1/8th mile, but he loves it.

I have an 06 C6, but haven't tried it yet.

 

What's an automatic??

 

I would like to see an A6 with 3.42 or 3.90 or even 4.10. Those gears and a TC would be impressive.

 

They're the ones that START (automatically).

 

3.90s and 4.10s would be WAY too steep for this trans IMO, unless you're using it for short track midget/sprint car racing or something.
Even 3.42s might render that first gear useless...3.15s or even only 2.73s might be the ones.