Top speed C6
Team Owner
Joined: Jul 2004
Posts: 40,375
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From: Redondo Beach, California
Can't answer the particulars. Note that a A6 C3 (base 433 hp engine) will max out at about 190 to 191 mph in 5th gear. The final 6th speed is just too tall for the engine at the high resistance of air drag at high speed.
I bought my 08 with a "performance option" rear end gear ratio of 2.74:1!!!!! Just imagine that. 40 years ago, a performance rear end gear ratio would have been 4.11:1.
I bought my 08 with a "performance option" rear end gear ratio of 2.74:1!!!!! Just imagine that. 40 years ago, a performance rear end gear ratio would have been 4.11:1.
Team Owner
Joined: Feb 2001
Posts: 27,253
Likes: 133
From: Short Hills, NJ
I think you meant C6?
And the base engine is actually 430hp (436 with the optional NPP exhaust).
Close, 2.73s actually. 
True, but of course most (none) of the automatics back then had a 4.02 first gear either. 
Those 2.73s matched with the A6/6L80 can actually make for some nice overall gearing depending on one's application.
And the base engine is actually 430hp (436 with the optional NPP exhaust).
Those 2.73s matched with the A6/6L80 can actually make for some nice overall gearing depending on one's application.
Team Owner
Joined: Feb 2001
Posts: 27,253
Likes: 133
From: Short Hills, NJ
I would think that the 2006/2007 A6 (2.56) cars would have a slightly higher top speed than the 2005 A4 cars but it could be close.
I'm just not sure which gear would even be best in the attempt to achieve that top speed with either trans. I'm thinking that 5th in the A6 would be the one to go with (as mentioned above) but maybe 3rd in the A4? And then that brings up another debate, we know for acceleration that the 3.15 geared A4 cars are quicker than the 2.73 geared A4 cars but perhaps for a top speed blast the 2.73 geared A4 car could better utilize 3rd gear (avoiding overdrive) without running out of RPM and maybe top out higher?
Not sure.
All I know is that one of the major magazines got a manual LS2 up to 191mph back then and that was/is impressive as hell.
Le Mans Master
Joined: Oct 2006
Posts: 5,078
Likes: 19
From: Cumming, GA
We've since moved it to the C6Z stock speed limiter which is 205mph.
I know of a guy that has a H/C A4 that also hit the 186mph speed limiter on a long stretch of hwy.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Over 150 mph drag is severe.
From comparing on this website, looks like the 2:73's in tha A4 would be best at 189 in 3rd.
The 3:15's would be at 164 (it's not going to pull that 2.20 final ratio in 4th)
And the a6 is 175 in 4th. It will not pull that 2.18 final ratio in 5th...
I say this because With my 4.10's my 5th ratio final ratio is 2.91...and it barely pulled it to my redline of 6700 in 5th at 185 mph.
I have 450 rwhp. If you have more these results may vary.
http://xse.com/leres/bin/gearratio?t...diameter=26.75
From comparing on this website, looks like the 2:73's in tha A4 would be best at 189 in 3rd.
The 3:15's would be at 164 (it's not going to pull that 2.20 final ratio in 4th)
And the a6 is 175 in 4th. It will not pull that 2.18 final ratio in 5th...
I say this because With my 4.10's my 5th ratio final ratio is 2.91...and it barely pulled it to my redline of 6700 in 5th at 185 mph.
I have 450 rwhp. If you have more these results may vary.
http://xse.com/leres/bin/gearratio?t...diameter=26.75
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Thread Starter
Instructor
Joined: Aug 2009
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it looks like the 2007 2.56 a6 shifts to 5th at 180 mph and rpms drop back to 4700rpm in 5th but keeps on climbing very slowly, is it possible to go above 186mph in 5th?
Last edited by Randy_medion; Mar 21, 2011 at 02:12 PM.
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
Over 150 mph drag is severe.
From comparing on this website, looks like the 2:73's in tha A4 would be best at 189 in 3rd.
The 3:15's would be at 164 (it's not going to pull that 2.20 final ratio in 4th)
And the a6 is 175 in 4th. It will not pull that 2.18 final ratio in 5th...
I say this because With my 4.10's my 5th ratio final ratio is 2.91...and it barely pulled it to my redline of 6700 in 5th at 185 mph.
I have 450 rwhp. If you have more these results may vary.
http://xse.com/leres/bin/gearratio?t...diameter=26.75
From comparing on this website, looks like the 2:73's in tha A4 would be best at 189 in 3rd.
The 3:15's would be at 164 (it's not going to pull that 2.20 final ratio in 4th)
And the a6 is 175 in 4th. It will not pull that 2.18 final ratio in 5th...
I say this because With my 4.10's my 5th ratio final ratio is 2.91...and it barely pulled it to my redline of 6700 in 5th at 185 mph.
I have 450 rwhp. If you have more these results may vary.
http://xse.com/leres/bin/gearratio?t...diameter=26.75
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
If you'd care to listen, check out how fast I get up to 130ish (top of 4th) and long it takes to pull 5th to 185. I'm pulling a 2.91 final ratio in 5th with my 4.10's. No way the car would pull a 2.18 ratio, it would just fall flat on its face like my buddy's did when he shifted to 6th.
Me:
Listen to my buddy when he shifts to 6th and the 2.18 final drive. His car holds speed but doesn't accelerate.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
In case you didn't notice, GM changed the 5th gear in the c6 and c6Z from the c5Z so that they could claim those 186 and 199 top speeds. The c5Z has a short 5th that tops out at redline at 169.7 vs 213 in the c6...(drag limited to 186). The Zr1 has a much shorter 6th and gets 205 in 6th if my memory is accurate from reading magazines..
Last edited by Joe_G; Mar 21, 2011 at 03:44 PM.
Team Owner
Joined: Feb 2001
Posts: 27,253
Likes: 133
From: Short Hills, NJ
And then that brings up another debate, we know for acceleration that the 3.15 geared A4 cars are quicker than the 2.73 geared A4 cars but perhaps for a top speed blast the 2.73 geared A4 car could better utilize 3rd gear (avoiding overdrive) without running out of RPM and maybe top out higher?
Le Mans Master
Joined: Oct 2007
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From: Greater Detroit Metro MI, when I'm not travelling.
The C5 Z06 will hit its rev limiter in 5th gear at 177MPH. Mine did exactly that at an indicated 179mph on the HUD in a long stretch of road.\
Shifting to 6th will drop you out of the powerband and the car will lose speed.
Team Owner
Joined: Feb 2001
Posts: 27,253
Likes: 133
From: Short Hills, NJ
That's a good point. 
I forgot which magazine it was (either Car & Driver or Road & Track) but right there on the cover they claimed 191mph. I know they admitted to folding in the mirrors and there might've been a tail wind for that run, maybe they found a way to 'trick' the limiter too?
I forgot which magazine it was (either Car & Driver or Road & Track) but right there on the cover they claimed 191mph. I know they admitted to folding in the mirrors and there might've been a tail wind for that run, maybe they found a way to 'trick' the limiter too?
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
I am sorry my comment above was based on the 4.10 gears my friend has. I edited my remarks.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
That's a good point.
I forgot which magazine it was (either Car & Driver or Road & Track) but right there on the cover they claimed 191mph. I know they admitted to folding in the mirrors and there might've been a tail wind for that run, maybe they found a way to 'trick' the limiter too?
I forgot which magazine it was (either Car & Driver or Road & Track) but right there on the cover they claimed 191mph. I know they admitted to folding in the mirrors and there might've been a tail wind for that run, maybe they found a way to 'trick' the limiter too?
The speed limiter exists for sure at 186. In fact there are two speed limiters, one's for when you have a flat tire (that one is at 80, not 55 as the DIC says BTW).
The Zr1's speed limiter is 210 BTW.
Keep in mind at that speed, it's likely either the car's vss calculation or the radar gun was off!
Last edited by Joe_G; Mar 21, 2011 at 03:46 PM.
Le Mans Master
Joined: Oct 2006
Posts: 5,078
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From: Cumming, GA
Team Owner
Joined: Feb 2001
Posts: 27,253
Likes: 133
From: Short Hills, NJ
Maybe they taped them into the folded position as they also used some duct tape elsewhere on the car during that pass.
That could be it.
Here is a quote from this article (http://www.corvettefever.com/feature...ive/index.html) that I believe also references the very same top speed test that I spoke of above:
But it didn't take long at that point to settle in and take it to 186 mph. The team had their record by running at 300 kph in both directions on the course.
Then, just ahead at 186 mph...
Later in the day after the record was secure, the team decided just for fun to pull in the outside mirrors and add a little duct tape to the car for another run. If you can touch 186 mph; well, you can certainly make 190. Right?
Approaching the almost vertical banking, Neal had it flat out and spotted a roadrunner (a bird, not a Plymouth) coming up the banking. "I'm in the middle of the corner," said Neal who was totally committed to his line at that point. "Well, I was pointed where he was going." We all sat on the edge of our seats, knowing you don't dodge something at that speed. What happened? "Well, did you ever see how smoke looks in wind-tunnel testing?" After all those years, all Wile E. Coyote needed to catch the roadrunner was a C6.
While certainly not happy about hitting anything, Neal stayed the course with his right foot buried. With folded mirrors and duct tape, they hit 190 mph, topped off the tank, and drove it home.
That could be it. Here is a quote from this article (http://www.corvettefever.com/feature...ive/index.html) that I believe also references the very same top speed test that I spoke of above:
But it didn't take long at that point to settle in and take it to 186 mph. The team had their record by running at 300 kph in both directions on the course.
Then, just ahead at 186 mph...
Later in the day after the record was secure, the team decided just for fun to pull in the outside mirrors and add a little duct tape to the car for another run. If you can touch 186 mph; well, you can certainly make 190. Right?
Approaching the almost vertical banking, Neal had it flat out and spotted a roadrunner (a bird, not a Plymouth) coming up the banking. "I'm in the middle of the corner," said Neal who was totally committed to his line at that point. "Well, I was pointed where he was going." We all sat on the edge of our seats, knowing you don't dodge something at that speed. What happened? "Well, did you ever see how smoke looks in wind-tunnel testing?" After all those years, all Wile E. Coyote needed to catch the roadrunner was a C6.
While certainly not happy about hitting anything, Neal stayed the course with his right foot buried. With folded mirrors and duct tape, they hit 190 mph, topped off the tank, and drove it home.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
Maybe they taped them into the folded position as they also used some duct tape elsewhere on the car during that pass.
That could be it.
Here is a quote from this article (http://www.corvettefever.com/feature...ive/index.html) that I believe also references the very same top speed test that I spoke of above:
But it didn't take long at that point to settle in and take it to 186 mph. The team had their record by running at 300 kph in both directions on the course.
Then, just ahead at 186 mph...
Later in the day after the record was secure, the team decided just for fun to pull in the outside mirrors and add a little duct tape to the car for another run. If you can touch 186 mph; well, you can certainly make 190. Right?
Approaching the almost vertical banking, Neal had it flat out and spotted a roadrunner (a bird, not a Plymouth) coming up the banking. "I'm in the middle of the corner," said Neal who was totally committed to his line at that point. "Well, I was pointed where he was going." We all sat on the edge of our seats, knowing you don't dodge something at that speed. What happened? "Well, did you ever see how smoke looks in wind-tunnel testing?" After all those years, all Wile E. Coyote needed to catch the roadrunner was a C6.
While certainly not happy about hitting anything, Neal stayed the course with his right foot buried. With folded mirrors and duct tape, they hit 190 mph, topped off the tank, and drove it home.
That could be it. Here is a quote from this article (http://www.corvettefever.com/feature...ive/index.html) that I believe also references the very same top speed test that I spoke of above:
But it didn't take long at that point to settle in and take it to 186 mph. The team had their record by running at 300 kph in both directions on the course.
Then, just ahead at 186 mph...
Later in the day after the record was secure, the team decided just for fun to pull in the outside mirrors and add a little duct tape to the car for another run. If you can touch 186 mph; well, you can certainly make 190. Right?
Approaching the almost vertical banking, Neal had it flat out and spotted a roadrunner (a bird, not a Plymouth) coming up the banking. "I'm in the middle of the corner," said Neal who was totally committed to his line at that point. "Well, I was pointed where he was going." We all sat on the edge of our seats, knowing you don't dodge something at that speed. What happened? "Well, did you ever see how smoke looks in wind-tunnel testing?" After all those years, all Wile E. Coyote needed to catch the roadrunner was a C6.
While certainly not happy about hitting anything, Neal stayed the course with his right foot buried. With folded mirrors and duct tape, they hit 190 mph, topped off the tank, and drove it home.
