top speed with 4.10's?
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 235
From: Bangkok, Thailand
top speed with 4.10's?
The Daytona thread in the general section wound around to my comment about the potential to use 6th gear with 4.10's and the question that goes with that is what top speed could a coupe really hit with that combo? I say coupe only because the FRC/Z06 roof line isn't as aerodynamic as the coupe.
So, does anyone here have real numbers on top speed in 6th with 4.10's? From my speed spread sheet it looks like 6000 rpm in 5th with 4.10's would be about 153 or so - I'm wondering if the extra gearing of the 4.10's would put the engine into a range where it could pull in 6th rather than slow down like has been reported with shifting into 6th with 3.42's.
So, does anyone here have real numbers on top speed in 6th with 4.10's? From my speed spread sheet it looks like 6000 rpm in 5th with 4.10's would be about 153 or so - I'm wondering if the extra gearing of the 4.10's would put the engine into a range where it could pull in 6th rather than slow down like has been reported with shifting into 6th with 3.42's.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
The Daytona thread in the general section wound around to my comment about the potential to use 6th gear with 4.10's and the question that goes with that is what top speed could a coupe really hit with that combo? I say coupe only because the FRC/Z06 roof line isn't as aerodynamic as the coupe.
So, does anyone here have real numbers on top speed in 6th with 4.10's? From my speed spread sheet it looks like 6000 rpm in 5th with 4.10's would be about 153 or so - I'm wondering if the extra gearing of the 4.10's would put the engine into a range where it could pull in 6th rather than slow down like has been reported with shifting into 6th with 3.42's.
So, does anyone here have real numbers on top speed in 6th with 4.10's? From my speed spread sheet it looks like 6000 rpm in 5th with 4.10's would be about 153 or so - I'm wondering if the extra gearing of the 4.10's would put the engine into a range where it could pull in 6th rather than slow down like has been reported with shifting into 6th with 3.42's.
That is why we use 3.42s
6700 Red line 4th gear, is 155-157 mph depending in tire air pressure. Shifting to 5th ( with a 1500 rpm drop to 5200 rpms) is 161 - 163
6th gear in the corvette is a highway gas milage gear not a performance gear.
Only the ZR1 gear ( GM Motorsports ratio) ratio is a performance gear.
4.10s are for acceleration, not top end.
Last edited by AU N EGL; Feb 21, 2011 at 03:36 PM.
Racer
Joined: Oct 2010
Posts: 260
Likes: 0
From: Bend Oregon
I don't have an answer but I do have an opinion. There is nothing wrong with your question. These cars are a hobby and asking hypothetical questions are part of that hobby. I for one also want to know if 6th gear will pull with 4:10s at high speed......just curious.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Burning Brakes
Joined: Dec 2009
Posts: 842
Likes: 45
From: St Paul, MN; Orlando, FL
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 235
From: Bangkok, Thailand
Thanks for the feedback guys! The questions wasn't about doing anything stupid on the street, it was about running on a track like Daytona or Talledega and the possibility of getting more top speed out of a mildly modded LS1 coupe by giving it better gearing to work with.
I realize 6th is only there for mileage and it does a great job at that. The question still stands though so maybe someone who has 4.10's will chime in with an answer.
I realize 6th is only there for mileage and it does a great job at that. The question still stands though so maybe someone who has 4.10's will chime in with an answer.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
You have a spreadsheet already? Where does rpm's in 6th gear with the 4.10 gears land compared to the old gears? Compare 6th with 4.10 gears vs 5th with 3.42 gears and see where in the power band you are with each combo. If you put the engine at a rpm where the hp is higher then it will be able to accelerate thecar to a higher speed. Figuring out how much more speed is the hard part. Well on paper it's tricky but if you drive it you'll find out.
Peter
Peter
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Thanks for the feedback guys! The questions wasn't about doing anything stupid on the street, it was about running on a track like Daytona or Talledega and the possibility of getting more top speed out of a mildly modded LS1 coupe by giving it better gearing to work with.
I realize 6th is only there for mileage and it does a great job at that. The question still stands though so maybe someone who has 4.10's will chime in with an answer.
I realize 6th is only there for mileage and it does a great job at that. The question still stands though so maybe someone who has 4.10's will chime in with an answer.
Melting Slicks
Joined: Mar 2001
Posts: 2,979
Likes: 281
From: Tulsa OK
I have seen the top of 5th gear with my 4.10s, which is 172 mph at 6700 rpms. This was in a one mile shootout as part of the Sandhills Open Road Race, last August. I haven't had an opportunity to try and pull 6th gear at that speed. I don't think I've ever been over 100 mph in 6th gear.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 235
From: Bangkok, Thailand
I have seen the top of 5th gear with my 4.10s, which is 172 mph at 6700 rpms. This was in a one mile shootout as part of the Sandhills Open Road Race, last August. I haven't had an opportunity to try and pull 6th gear at that speed. I don't think I've ever been over 100 mph in 6th gear.
Pro
Joined: Oct 2009
Posts: 600
Likes: 0
From: Bowling Green KY
Just for documentation purposes, in controlled conditions, I took my 2003 C5 Coupe mn6 all the way to 170 in 5th gear and it was just getting into the red stuff on the tach and I shifted to 6th and it acted like it bogged down. So I shoved it back into 5th and ran it up to 177. That was plenty for me.
But as the OP stated, what reargears would be necessary to allow 6th to "pull" at those speeds. I read the comments about spreading it out on a spreadsheet. However, I believe the OP wanted to hear from someone as crazy as us that actually went out and did it with the specific intent of getting 6th gear efficiently involved in the pull.
Who knows, no one may have been as crazy as we are !!!!
But as the OP stated, what reargears would be necessary to allow 6th to "pull" at those speeds. I read the comments about spreading it out on a spreadsheet. However, I believe the OP wanted to hear from someone as crazy as us that actually went out and did it with the specific intent of getting 6th gear efficiently involved in the pull.
Who knows, no one may have been as crazy as we are !!!!
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Peter
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
I had only had my '98 a few weeks and in a controlled environment found that the car really struggled in 6th starting around 143-144. Didn't know/think about dropping back into 5th to get back in the fat part of the torque curve. I really think the 4.10 might be enough to get far enough into the torque curve so that top end might not be that much different from the 3.42. I want to remember that 5th is a .75 overdrive and 6th is a .5 overdrive.
Charlie
Charlie
Pro
Joined: Oct 2009
Posts: 600
Likes: 0
From: Bowling Green KY
I had only had my '98 a few weeks and in a controlled environment found that the car really struggled in 6th starting around 143-144. Didn't know/think about dropping back into 5th to get back in the fat part of the torque curve. I really think the 4.10 might be enough to get far enough into the torque curve so that top end might not be that much different from the 3.42. I want to remember that 5th is a .75 overdrive and 6th is a .5 overdrive.
Charlie
Charlie
Pro
Joined: Oct 2009
Posts: 600
Likes: 0
From: Bowling Green KY
I know the proof is in the testing but the first step is to look at the gear ratios and the engine power. If you drop the engine to a lower HP you won't pull a higher speed. There is no if, and or but maybe here. If the engine does not produce more HP in 6th gear then the car won't go faster. The top speed of a C5 coupe is around 173mph. So, check the HP of a stock car at that speed and then check again using the 6th gear ratio and your new rear gear ratio. The HP change will tell you if it's a winning or losing combination.
Peter
Peter
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 235
From: Bangkok, Thailand
I just tried to post my spread sheet info, but it didn't work.
I'll upload it here: http://www.marcmedina.com/c5/gears.xls
Looks like with 4.10's and shifting at 6000 drops the rpm to about 4000-4100 rpm.
I'll upload it here: http://www.marcmedina.com/c5/gears.xls
Looks like with 4.10's and shifting at 6000 drops the rpm to about 4000-4100 rpm.
Last edited by mcm95403; Feb 23, 2011 at 01:06 AM.