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Discussion Starter · #1 ·
I see a C6 at the track about every time out lately and I am convinced that the A6 is the fastest. I think the slowest one I saw was a 12.2 and it was, so he said, stone stock. No bolt ons etc.

Fastest one was a 11.82 ( I think) car that had bolt ons and a tune by Fasterproms. **It was all the driver and none of Jeremy's work ** :surprised
Would I lie?

Both were running the stock junk Goodyear too !!

The manual is more fun but after driving the ZF trannie it is just a junk, rock box trannie: if you blow one up call G-Force for a real trans for the car. I have the manual but truly dislike it's shifting and lack of strength.

The A4 seems to be a bit slower than the manual but not by too much.

Having said all of the above I must admit to seeing about 12 of them all together at the track.

Won't be out again until the last weekend in August as I am converting the 'company car' to methanol. I can't feed my habit . . . . for almost a month. :nuts:
 

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If you are a good driver the manual is faster-GM and car rags agree.
 

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Hmm we have a few A6's out at our track too, and no one runs a 12.2.

I think one of the modded ones (Glennhl), intake and lg's, has hit 12.5 at 114 with a 1.90 60' and I think that is pretty consistent for him now. I am gonna guess the 3 mph he has on me is from the mods, not the A6.

Most of the manual guys including myself at our track get around a 2.10 on average. So yeah he has a 4 tenth advantage from the launch, which is why my best is still 13.06 :(.

Everytime I've raced an A6, he's beat me out of the hole and I've reeled him in by the end of 3rd. I haven't raced Glennhl since his car was green and stock though. I am sure he would beat me now.

If I could get a 1.9 60', things would be a different story, and I would finally see my 12's.

You guys must be really low (sea level), and have a very well prepped track if the slowest guys are running 12.2's.

Even if the A6 can leave the hole quicker and doesn't have as big of a TM problem, it's still an automatic, and something just seems wrong about that.
 

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The A6 is quicker than the M6 if, and it's a big if, you can work around the TM in the tranny....it's something the m6 guys don't have to worry about. When I've raced manuals(not vettes only, but a mix), 2nd and 3rd in the A6 pulls alot harder than theirs. If you get a chance to own or drag race an A6, do it....it'll win over more people than you'd think.
 

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I guess I can understand why the A6 might be better in a 1/4 mile drag race, but how do the different trannys compare on the street? I mean from like a 40mph roll.
 

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The M6 Z51 still has a gearing advantage over the A6/2.73 in 2nd and 3rd (not 1st). So from a roll in 2nd or 3rd at 40mph, the MN6 will be faster. There is also a little more frictional loss with the A6 than there is with the manual as shown on the dyno.

I grabbed these from that other forum.

6M w/ Z51
2.97
2.07
1.43
1.00
0.71
0.57
3.42

6M w/o Z51
2.66
1.78
1.30
1.00
0.74
0.50
3.42

6A
4.02
2.36
1.53
1.15
0.85
0.67
2.56/2.73
 

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Discussion Starter · #7 ·
JD,

I want to do the overall gearing on both the manual and the A6. Do you know the differential ratio for the A6? The math would explain a lot.

Thanks.
 

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I thought that was the 2.56/2.73 at the bottom of the A6 list.

I am not wrong in thinking that the final drive is the same as the differential am I?
 

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Discussion Starter · #9 ·
Being bot old and stupid I didn't notice it - - will do the math and get back to you. Sorry - - old age or something . . :crazy:
 

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Discussion Starter · #10 ·
OK, I did the overall gearing math for three units: the Z51 wM6, plain M6 and the A6 with the 2.73 differential. As you know if you multiply the gear ratios by the differential ratio you will get the overall 'gearing' for the car and the higher the number numerically the lower the gearing. In most cases or until HP is above about 750 to the wheels lower gearing is better.

I will try to type these side by side (probably screw it up)

Z51/M6 M6 A6/2.73 differential


First gear
10.1 9.09 10.9

2nd
7.07 6.08 6.44

3rd
4.89 4.44 4.17

4th
3.42 3.42 3.20

In most drag applications a change of over .5 is considered significant.

So the A6 is geared lower in first, second lowest in second gear, lowest in third and 4th is a give away.

Looking at the overall gearing you can see where he supposed 'significant' changes are and draw your own conclusions.

A caveat if I may: a torque converter change is worth .2-3 seconds in ANY automatic Vette. I never asked the owners about their converters - who knows but the A6 cars were still the quickest down the track.

I think the big problem is the crap double A arm suspension on the ass end, great for road racing but just as bad as can be for straight line acceleration and the manual trannies have the most trouble in first gear - - always. I would think the auto would have far less problems in this situation. Having said that I know you can now tune first for wheel hop. Jeremy wanted to do this to mine and I said no, he just shook his head.

Now the C4's had a four link and they would just $hit and get with the manual trannie.
 

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If you are a good driver the manual is faster-GM and car rags agree.
The fastest Vettes have always been automatics. Check the records. No mater how fast you shift there is a lag in power between shifts. A planetary transmission is never off power. Two stock C6s given equally skilled drivers and no mistakes the A6 will out perfrom the MN6 in the quarter everytime.

:cheers:
 

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Discussion Starter · #12 ·
Midnight,

There is one exception to this and that is the clutchless manual trans such as a Liberty or a G-Force (pro stock trans) which allows no power lag - - just aren't street able. Other wise you are completely correct in my opinion.

After going to methanol this month, and if I have the $$ I will convert to a G-Force pro stock trannie for better ETand MPH as the parasitic loss in them is - get this - 3%. 7% more power to the wheels is very significant.

Parasitic loss in racing automatics are about 10%, M6 cars are about 16% and street automatics with stock converters are about 20%. A good converter is worth about 3-4% less loss.
 

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The older gear ratio(pre 08) is actually better for the 1/4 mile. 2.56's I belive. You can got through the traps in 3rd at over 116mph stock, with the new 2.73 you 'll need to shift to (4) in order to cross without hitting the "X" and losing more time.This is assuming you're in paddle shift mode. If just in "S", it'll still change to (4) after about 106MPH.
 

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Yeah, that's how I drew my conclusions that the MN6 is faster than the A6 in 2nd and 3rd. There is 16% (7.07 vs 6.08) more torque hitting the ground in second in a manual car, and 10% (4.89 vs 4.44) more in 3rd.

I've witnessed this many times at the track as well. With the more consistent launch, it's a close call by the end of 3rd, but I've never lost to a stock A6, and I have never broke 13. Plus, it is a nice little adrenaline booster to lose a car length or so and reel him in down the track.

I understand that funny cars and drag cars are automatics (for very good reasons), but in a street car, an auto takes a lot of the fun and skill out of racing. I agree there is some technique when launching the car, with power braking and what not, but once you are out of the hole, all you do is keep your right foot planted and the steering wheel straight.

My best and favorite run where I ran the 13.06 was actually against a modded Viper GTS. His best run of the day was 11.9, but against me he blew the launch and had a bad 2-3 shift, and I won by a nose. An auto would take all the fun and competition out of it.

I thought of one more thing. We Z51 MN6's redline at the worst possible moment, 104mph, which means we shift with only a couple hundred feet left. The A6 redlining at 114.5mph should never shift to 4th, so it should gain on the MN6 at the very end. I'd have to study a dyno plot to make sure, but that should be right.

Bottom line is if the A6 was actually faster than the Z51 in the 1/4, then GM would list the 1/4 time for the A6, and send the A6 to the rags for testing. And they would want to do this because the A6 is now a $1250 option.

A bunch of us are going to Firebird Aug 10th. It'll still be hot as hell so I don't expect any records, but I'll let you know exactly how all the A6's do. Unfortunately, I believe I am the only guy left that is 100% stock.
 

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Even though I'm not stock,I hope this input may help. My car doesn't shift into (4) in the 1/4 mile and it's turning just over 120mph at the stripe. I've had a tune , of course, and 113rwhp more than a stock A6. When in paddle mode, I can go past 120mph still in third and still not be redlining. I really think that more A6 owners really need to spend more time learning the tranny. It's far more advanced and performance oriented than most belive and can hold a ton of torque before giving up the ghost. I'd love to see what a truely seasoned driver of an A6 (100+passes) can do bone stock, once TM and the A6 is learned. 12.2 is the best bone stock I've seen (05-07's), but even without the added HP and gearing of the 08's and up, there may be a little more on the table. I also belive that the TM will more adversly effect the new LS3 A6s as there is more torque than in previous C6 years and the percentage of TM applied will be greater at launch and transmission shift. It's a wait and see thing, but I can attest to actually going faster with the tires spinning and less HP/TQ than hooking up and more HP/TQ. If it's spinning and TC is off, the car doesn't read as much torque and doesn't apply the TM as greatly as it does when you hook . Now I'm not saying go down the track sideways, but I'd love more info from A6 drag racers on the subject. Most everyone I've encountered that races their vettes have M6s and are not helpful in this area. Old dog, if you have some track experience and know what I'm talking about in the A6, let it bleed out, buddy. As far as the M6 vs A6 from a roll....if both cars down shift at the same speed and take off, the M6 will have a slight advantage for a second or so, maybe getting a fender ahead, the the A6 will pull up to and sometimes past the M6 in the selected gear, before next gear change. If the A6 driver leaves the car in S or D and, from a roll, the M6 driver down shift and they both accelerate, the M6 will take it by half a car or greater. It's all in how familiar you are with the A6 tranny. I feel that most of the people who got it , did it for the novelty of it and not for the performance aspect.
 

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That is helpful. Those numbers were from the 2008 A6. Didn't know they were different from 06-07 actually. Do you have the 2.73 or the 2.56? Or were those numbers different as well?

I would be nice not to have to shift to 4th. 4th isn't a lot of fun. Huge difference in acceleration between 3 and 4.
 

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That is helpful. Those numbers were from the 2008 A6. Didn't know they were different from 06-07 actually. Do you have the 2.73 or the 2.56? Or were those numbers different as well?

I would be nice not to have to shift to 4th. 4th isn't a lot of fun. Huge difference in acceleration between 3 and 4.
I have the 06 2.56 A6 Z51. Whats strange is in (S) first gear is not as strong as when the car is paddle shifted. I can barely shift in time from 1 to 2, but when it hits(hooks hard) in 2nd, TM kicks in for a second(does in 3rd as well), so I've been tracking the car in just (S) mode until I can futher figure things out.
 

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Hmm we have a few A6's out at our track too, and no one runs a 12.2.

I think one of the modded ones (Glennhl), intake and lg's, has hit 12.5 at 114 with a 1.90 60' and I think that is pretty consistent for him now. I am gonna guess the 3 mph he has on me is from the mods, not the A6.

Most of the manual guys including myself at our track get around a 2.10 on average. So yeah he has a 4 tenth advantage from the launch, which is why my best is still 13.06 :(.

Everytime I've raced an A6, he's beat me out of the hole and I've reeled him in by the end of 3rd. I haven't raced Glennhl since his car was green and stock though. I am sure he would beat me now.

If I could get a 1.9 60', things would be a different story, and I would finally see my 12's.

You guys must be really low (sea level), and have a very well prepped track if the slowest guys are running 12.2's.

Even if the A6 can leave the hole quicker and doesn't have as big of a TM problem, it's still an automatic, and something just seems wrong about that.
My best is 12.52 at 114.43, but it was with a 1.942 60 foot time, not a 1.90. The 1.94 is the best 60 I've pulled, but then again, I refuse to do a burnout because I'm CHEAP and the Supercar tires are expensive. I just do a little "dry hop."

The reason you see the higher times at Firebird are twofold. First, my best ET was with a 2300 foot density altitude, so we don't get very good air. Second, in my opinion, Firebird does a poor job of track prep on Friday nights. I leave the line at idle.

Personally, I think a well drivien M6 should be faster. There is no reason (other than the dreaded wheel hop) that a M6 shouldn't be able to pull 1.94 60's. Whenever I run CBRF at Firebird (06 M6 Z51 1LT), he leaves off at idle to avoid wheel hop, pulls 2.2 second 60 foots and then spends the next 3 gears catching me! If he pulled an equivalent 60 foot time, he would beat me every time. And he's done less mods. I have LG LT headers, CAI, and a 160 stat. He's done a ported intake, K&N inlet, Magnaflow Mufflers, and a 160 stat.
 

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Thanks for chiming in Glen. I was a little off on the 60' I guess, but glad you backed me up on the "catching" the A6. Are you coming out next Friday?

I miss the track. Last time I was there and ran was April of '06.
 

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I have the 06 2.56 A6 Z51. Whats strange is in (S) first gear is not as strong as when the car is paddle shifted. I can barely shift in time from 1 to 2, but when it hits(hooks hard) in 2nd, TM kicks in for a second(does in 3rd as well), so I've been tracking the car in just (S) mode until I can futher figure things out.
Guess there is a little more involved than just pressing and going. The posts I have read say to leave at half throttle from idle, then at about a car length, roll on the gas. How many modes are there, just (S)port and regular?

You would think that the computer can shift better than the paddles, but the paddles probably make it more fun. What happens if you have it in paddle mode and just pin it, won't the car shift at redline like most "manual" automatics?
 
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