Top speed
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
181MPH in 5th gear, where shifting into 6th will drop the RPMs down to about 5400RPM. It probably will not make enough power at 5400RPM to continue accelerating past 181MPH on a level road; I know my stock C5 Z06 would hit 179MPH in 5th and the lose speed once I shifted into 6th gear because there just wasn't enough power at that gear, at that RPM to keep pulling.
If it had the power for it, 6th gear with 4.10s will do 201MPH at 6000RPM, 218 at 6500 and 230 at 6800.
To go 201MPH a C6 will need somewhere around 470 - 480 at the rear wheels, at the RPM you are reaching that speed at, and a lot of road.
I believe Spinmonster has done it with a H/C car? Maybe he can comment...
If it had the power for it, 6th gear with 4.10s will do 201MPH at 6000RPM, 218 at 6500 and 230 at 6800.
To go 201MPH a C6 will need somewhere around 470 - 480 at the rear wheels, at the RPM you are reaching that speed at, and a lot of road.
I believe Spinmonster has done it with a H/C car? Maybe he can comment...
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
181MPH in 5th gear, where shifting into 6th will drop the RPMs down to about 5400RPM. It probably will not make enough power at 5400RPM to continue accelerating past 181MPH on a level road; I know my stock C5 Z06 would hit 179MPH in 5th and the lose speed once I shifted into 6th gear because there just wasn't enough power at that gear, at that RPM to keep pulling.
If it had the power for it, 6th gear with 4.10s will do 201MPH at 6000RPM, 218 at 6500 and 230 at 6800.
To go 201MPH a C6 will need somewhere around 470 - 480 at the rear wheels, at the RPM you are reaching that speed at, and a lot of road.
I believe Spinmonster has done it with a H/C car? Maybe he can comment...
If it had the power for it, 6th gear with 4.10s will do 201MPH at 6000RPM, 218 at 6500 and 230 at 6800.
To go 201MPH a C6 will need somewhere around 470 - 480 at the rear wheels, at the RPM you are reaching that speed at, and a lot of road.
I believe Spinmonster has done it with a H/C car? Maybe he can comment...
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
on the dyno my car wont lock but on the street it does, now i haven't data logged it to see if its locked at wide open throttle in forth, but i think the last time i checked the tune it was set at a higher % to lock in third, but its just a single disk converter so i don't no if it holds, because it wont on the dyno, so we never get an accurate rwhp# since the converter went in, i have had the car to 165 in 4th at around 6100-6400 rpm, but that was just by the dash gauges not a data log, i got the 165 but not quite shore on the exact rpm
Team Owner
Joined: Feb 2001
Posts: 27,206
Likes: 105
From: Short Hills, NJ
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
What redline?
Let me assume you have no converter slip for a moment, and a redline of 6500RPM.
1st gear: 45MPH
2nd gear: 84MPH
3rd gear: 137MPH
4rth gear: 195MPH
4rth will be good for 180MPH at 6000RPM, 188MPH at 6250RPM, 195MPH at 6500RPM and 203MPH at 6750RPM. Considering automatic cars have considerably higher drivetrain losses than manuals, and how quickly these losses climb with higher stall converters, you will run out of horsepower before you run out of RPM for your theoretical top speed...
Now we introduce some torque converter slip there... With 10% torque converter slip you'd be doing 180MPH but actually spinning the engine at 6600RPM. Now you can run out of RPM well before you run out of power in that scenario.
Horsepower wise a cammed car should go into the 190ish MPH range. How fast yours goes will depend on the torque converter.
Good enough?
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
Non Z-51?
What redline?
Let me assume you have no converter slip for a moment, and a redline of 6500RPM.
1st gear: 45MPH
2nd gear: 84MPH
3rd gear: 137MPH
4rth gear: 195MPH
4rth will be good for 180MPH at 6000RPM, 188MPH at 6250RPM, 195MPH at 6500RPM and 203MPH at 6750RPM. Considering automatic cars have considerably higher drivetrain losses than manuals, and how quickly these losses climb with higher stall converters, you will run out of horsepower before you run out of RPM for your theoretical top speed...
Now we introduce some torque converter slip there... With 10% torque converter slip you'd be doing 180MPH but actually spinning the engine at 6600RPM. Now you can run out of RPM well before you run out of power in that scenario.
Horsepower wise a cammed car should go into the 190ish MPH range. How fast yours goes will depend on the torque converter.
Good enough?
What redline?
Let me assume you have no converter slip for a moment, and a redline of 6500RPM.
1st gear: 45MPH
2nd gear: 84MPH
3rd gear: 137MPH
4rth gear: 195MPH
4rth will be good for 180MPH at 6000RPM, 188MPH at 6250RPM, 195MPH at 6500RPM and 203MPH at 6750RPM. Considering automatic cars have considerably higher drivetrain losses than manuals, and how quickly these losses climb with higher stall converters, you will run out of horsepower before you run out of RPM for your theoretical top speed...
Now we introduce some torque converter slip there... With 10% torque converter slip you'd be doing 180MPH but actually spinning the engine at 6600RPM. Now you can run out of RPM well before you run out of power in that scenario.
Horsepower wise a cammed car should go into the 190ish MPH range. How fast yours goes will depend on the torque converter.
Good enough?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
It depends. If the car is horsepower limited and is outside of its powerband at the gear it tops out at, then having the torque converter slip will bring the engine higher up into the powerband and may allow a higher top speed.
On the other hand, if slip makes the engine run out of RPMs, then the torque converter will hurt the top speed.
If all else is the same then the added losses from a "looser" torque converter will lower top speed.
And if both converters lock up, then, as Dennis said, there will be no difference.
On the other hand, if slip makes the engine run out of RPMs, then the torque converter will hurt the top speed.
If all else is the same then the added losses from a "looser" torque converter will lower top speed.
And if both converters lock up, then, as Dennis said, there will be no difference.
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
The only accurate way I know of measuring the real power though is if you can get the converter to lock up somehow... Or put the engine on an engine dyno and multiply the result by your expected drivetrain losses
BTW looks like the Z51 A4 ratios are the same so those numbers should be pretty spot on... I took the real diameter of the tire and the actual published ratios to arrive at them.
Last edited by PowerLabs; Sep 1, 2009 at 01:09 PM.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
THAT is a very good question
The only accurate way I know of measuring the real power though is if you can get the converter to lock up somehow... Or put the engine on an engine dyno and multiply the result by your expected drivetrain losses
BTW looks like the Z51 A4 ratios are the same so those numbers should be pretty spot on... I took the real diameter of the tire and the actual published ratios to arrive at them.
The only accurate way I know of measuring the real power though is if you can get the converter to lock up somehow... Or put the engine on an engine dyno and multiply the result by your expected drivetrain losses
BTW looks like the Z51 A4 ratios are the same so those numbers should be pretty spot on... I took the real diameter of the tire and the actual published ratios to arrive at them.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
THAT is a very good question
The only accurate way I know of measuring the real power though is if you can get the converter to lock up somehow... Or put the engine on an engine dyno and multiply the result by your expected drivetrain losses
BTW looks like the Z51 A4 ratios are the same so those numbers should be pretty spot on... I took the real diameter of the tire and the actual published ratios to arrive at them.
The only accurate way I know of measuring the real power though is if you can get the converter to lock up somehow... Or put the engine on an engine dyno and multiply the result by your expected drivetrain losses
BTW looks like the Z51 A4 ratios are the same so those numbers should be pretty spot on... I took the real diameter of the tire and the actual published ratios to arrive at them.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
Here's a good website if you want to play around with gear ratios, rpm's, tire diameter, etc. Tire diameter makes a big difference as you will see.
http://xse.com/leres/ss/calculator.html
pan down on the page and choose your car/trans combo.
http://xse.com/leres/ss/calculator.html
pan down on the page and choose your car/trans combo.
Instructor
Joined: Jul 2009
Posts: 216
Likes: 0
I have a Fast 92 and 4.10 gears. 2 days ago lined up with a 600 sport bike on the highway. Actually he was 3 cars ahead of me when he crouched and hit it. Started at maybe 55mph. Was on him the whole way. Next to him at 120. Passing him at 130. Took it to 160 just to see what the car felt like. (just got it about 5 weeks ago) I was impressed to hand in there with him. Top end feels week but I think it needs a tune. Car also has 404 stroker and cam.
Advanced
Joined: Jun 2009
Posts: 62
Likes: 0
From: Maple ON
I thought C6's are supposed to be able to go 185MPH? I guess I should read the fine print next time... is the 185MPH claim a special model or is it just downhill/with the wind? :-)
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Drifting
Joined: Jun 2007
Posts: 1,437
Likes: 5
here's some background dyno info i have, see if you can formulate something from it, 375 rwtq 376 rwhp before converter then added pulley and the converter was in and a quick dyno 365 rwtq 357 rwhp added ported fast 400.4 rwtq 374.4 rwhp, now cam and ewp 481.8 rwtq and 422.8 rwhp
Thread Starter
Racer
Joined: May 2006
Posts: 431
Likes: 0
From: Houston TX
I have a Fast 92 and 4.10 gears. 2 days ago lined up with a 600 sport bike on the highway. Actually he was 3 cars ahead of me when he crouched and hit it. Started at maybe 55mph. Was on him the whole way. Next to him at 120. Passing him at 130. Took it to 160 just to see what the car felt like. (just got it about 5 weeks ago) I was impressed to hand in there with him. Top end feels week but I think it needs a tune. Car also has 404 stroker and cam.