[3.90 vs 4.10] First drive comparison
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
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From: Objects in your mirror are losing , Long Island, NY
St. Jude Donor '08
First I want to thank Chuck at CoW for coming thru on his word
I'm sure everyone thats a regular here in C6 Tech knows I was never really happy with the 4.10.......anyways, having the car apart, I had Chuck do a clutch upgrade, I went with the Textralia OZ-700 Single Disc Clutch so it came out to be a win-win situation for both of us.
For those that say, "3.90? all youre gonna gain 100rmps" thats
6th gear @ 2,000rpm
4.10 =66mph
3.90 =75mph
under normal cruising 70mph
4.10= 21 mpg
3.90= 27 mpg
6th gear @ 100 mph
4.10 =3,000 rpms
3.90 =2,700 rpms
strong pulls
4.10, all you see is the rpm needle sweeping to red line, now my mph needle is the one thats doing the sweeping to the right.
The car now goes from 80 to 130 in a flash...
No longer do I have to shift the hell out of the car and only be doing 80mph.....
welcome2try has been in my car when I had the 4.10, I would like to invite him to come for a drive to feel the difference
-Ed
I'm sure everyone thats a regular here in C6 Tech knows I was never really happy with the 4.10.......anyways, having the car apart, I had Chuck do a clutch upgrade, I went with the Textralia OZ-700 Single Disc Clutch so it came out to be a win-win situation for both of us.
For those that say, "3.90? all youre gonna gain 100rmps" thats
6th gear @ 2,000rpm
4.10 =66mph
3.90 =75mph
under normal cruising 70mph
4.10= 21 mpg
3.90= 27 mpg
6th gear @ 100 mph
4.10 =3,000 rpms
3.90 =2,700 rpms
strong pulls
4.10, all you see is the rpm needle sweeping to red line, now my mph needle is the one thats doing the sweeping to the right.
The car now goes from 80 to 130 in a flash...
No longer do I have to shift the hell out of the car and only be doing 80mph.....
welcome2try has been in my car when I had the 4.10, I would like to invite him to come for a drive to feel the difference
-Ed
And rather quickly I must add..
Last edited by welcome2try; Apr 11, 2008 at 08:29 PM.
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From: North Strand, NMB, SC; Retired x 2 (US Army: 70-90 AD) (US Army: 91-16 DAC); yea, I'm old.
but are you really set for the rally?
Melting Slicks
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From: NJ..."the way I saw it, everyone takes a beating sometimes."
I'm certainly not going to speak for Spin but having kept up to date on this topic, and you're situation inparticular Ed, no one was arguing that you wont have to shift more with 4.10s or the rpms might be slightly higher at a given speed. Those were and still seem to be your top priorities. However you cannot accurately say that 3.90s are faster than the 4.10s(in this set up) You say the car feels faster but I'm guessing it's because you can sit back for a spilt second and enjoy the acceleration before your next shift. With the 4.10s you probably had to shift sooner than you were comfortable with and you were missing out on how fast you were actually going. I only wish you could have gotten a few good runs with the 4.10s and then do a few comparitive runs with the 3.90s now. I don't see how they could be faster, but I don't know much, so....
Either way as I said before and as you've commented on. You're happy with your car.
Now go give the euro-trash an ***-whoopin!
Either way as I said before and as you've commented on. You're happy with your car.
Now go give the euro-trash an ***-whoopin!
Thread Starter
Team Owner
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From: Bann Camp & N.Y.C.
St. Jude Donor '08
the registration for the even is closed, it starts from Lamborghini of Long Island and end .........???
http://video.google.com/videoplay?do...83911318066421
http://video.google.com/videoplay?do...83911318066421
Team Owner
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From: NJ
St. Jude Donor '05-'08
I'm certainly not going to speak for Spin but having kept up to date on this topic, and you're situation inparticular Ed, no one was arguing that you wont have to shift more with 4.10s or the rpms might be slightly higher at a given speed. Those were and still seem to be your top priorities. However you cannot accurately say that 3.90s are faster than the 4.10s(in this set up) You say the car feels faster but I'm guessing it's because you can sit back for a spilt second and enjoy the acceleration before your next shift. With the 4.10s you probably had to shift sooner than you were comfortable with and you were missing out on how fast you were actually going. I only wish you could have gotten a few good runs with the 4.10s and then do a few comparitive runs with the 3.90s now. I don't see how they could be faster, but I don't know much, so....
The 4.10s are definately quicker, but if you are figuring in shifts one maybe faster with 3.90s because of sloppy slow shifts or because what their driving application dictates.
Many of the debates on this subject are strictly around 1/4 mile times. As long as you do not have to make the extra shift than the 4.10s will be faster in the 1/4 mile, but again if you are a person that is not into 1/4 mile you maybe faster with 3.90s.
I am not against 4.10s heck it was my first mod, but I hate this cramming down people's throat that 4.10s are what everyone needs. I know I have said it before, but I found on road courses that my 3.73s produced faster lap times than my 4.10s did.
In the end Ed is happy so that is what matters.
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From: Bethesda MD
4.10 to 3.90s is roughly a 5% reduction in gearing (.2 / 4.10). 9 mph gain at 2,000 is over 13% measured against the 4.10 speed. Then at 100 mph we have a 10% measured against the 3000 rpms.
I've checked a couple calculators and 4.10s at 2000 rpms in a z51 is 68 MPH and 3.90s are 72 mph. 75 mph corresponds to 3.73s for a z51. Since tire size can vary a couple tenths of an inch between between estimators, maybe the speedo reports a mph or so difference from these figures. The point is that one does not change gears by 5% and then see changes of 10% - 13% in rpm/mph.
BTW, the figures shown for Craigster05 using 4.10s with an F55 (base tranny) correspond to the 75 mph at 2000 rpm that my gear calculators show.
Last edited by Ragtop 99; Apr 12, 2008 at 10:05 AM.
Melting Slicks
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From: NJ..."the way I saw it, everyone takes a beating sometimes."
The 4.10s are definately quicker, but if you are figuring in shifts one maybe faster with 3.90s because of sloppy slow shifts or because what their driving application dictates.
Many of the debates on this subject are strictly around 1/4 mile times. As long as you do not have to make the extra shift than the 4.10s will be faster in the 1/4 mile, but again if you are a person that is not into 1/4 mile you maybe faster with 3.90s.
I am not against 4.10s heck it was my first mod, but I hate this cramming down people's throat that 4.10s are what everyone needs. I know I have said it before, but I found on road courses that my 3.73s produced faster lap times than my 4.10s did.
In the end Ed is happy so that is what matters.
Many of the debates on this subject are strictly around 1/4 mile times. As long as you do not have to make the extra shift than the 4.10s will be faster in the 1/4 mile, but again if you are a person that is not into 1/4 mile you maybe faster with 3.90s.
I am not against 4.10s heck it was my first mod, but I hate this cramming down people's throat that 4.10s are what everyone needs. I know I have said it before, but I found on road courses that my 3.73s produced faster lap times than my 4.10s did.
In the end Ed is happy so that is what matters.
Weasel what about full on, highspeed acceleration? Where you're going to hit 5th and 6th gear regardless? No 1320ft finish line. Wouldn't 4.10s still be faster?
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Thread Starter
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From: Bann Camp & N.Y.C.
St. Jude Donor '08
Sombody needs to show me the math on these #.
4.10 to 3.90s is roughly a 5% reduction in gearing (.2 / 4.10). 9 mph gain at 2,000 is over 13% measured against the 4.10 speed. Then at 100 mph we have a 10% measured against the 3000 rpms.
take the diff from 3.42 (stock) & 4.10, thats .68
take the diff from 3.90s & 4.10, thats .20
20/68=.2941*100= 29.4% diff between 3.90 & 4.10 gains
I've checked a couple calculators and 4.10s at 2000 rpms in a z51 is 68 MPH and 3.90s are 72 mph. 75 mph corresponds to 3.73s for a z51. Since tire size can vary a couple tenths of an inch between between estimators, maybe the speedo reports a mph or so difference from these figures. The point is that one does not change gears by 5% and then see changes of 10% - 13% in rpm/mph.
the math says 7, I've seen 9 driving down the hwy, so lets say I'm off by 1 mph
BTW, the figures shown for Craigster05 using 4.10s with an F55 (base tranny) correspond to the 75 mph at 2000 rpm that my gear calculators show.
4.10 to 3.90s is roughly a 5% reduction in gearing (.2 / 4.10). 9 mph gain at 2,000 is over 13% measured against the 4.10 speed. Then at 100 mph we have a 10% measured against the 3000 rpms.
take the diff from 3.42 (stock) & 4.10, thats .68
take the diff from 3.90s & 4.10, thats .20
20/68=.2941*100= 29.4% diff between 3.90 & 4.10 gains
I've checked a couple calculators and 4.10s at 2000 rpms in a z51 is 68 MPH and 3.90s are 72 mph. 75 mph corresponds to 3.73s for a z51. Since tire size can vary a couple tenths of an inch between between estimators, maybe the speedo reports a mph or so difference from these figures. The point is that one does not change gears by 5% and then see changes of 10% - 13% in rpm/mph.
the math says 7, I've seen 9 driving down the hwy, so lets say I'm off by 1 mph
BTW, the figures shown for Craigster05 using 4.10s with an F55 (base tranny) correspond to the 75 mph at 2000 rpm that my gear calculators show.
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From: salem OR
I have nothing to gain by BSing tech, even before the cam, I was complaining about the mpG, last night and this morning was the first time I've seen my mpG in high 20's before the 4.10........everyone knows and will confirm that I could not get over 22mpG average w/ 4.10. (keep in mind, same 2,000 rpms in 6th nets me 9 mpH more)
RE: Shifting,
to coast/cruise w/ 4.10 around 45~50mpH I would have to be in 5th gear.....everyone keeps saying there's not much of a diff, but there is.....I'll be making some drive video's.
Spin can chime in, Spin can even drive it.....80 to 130 was effordless, my speedometer needle was sweeping faster than the rpm needle and I didnt realize how fast the car got to 130+...........w/4.10, pass 110 I had to floor it & shift
I love it, and it's exactly what I wanted out of the car, a happy medium
You guys do remember what happened at the end of Chicken Little? The sky did fall down
RE: Shifting,
to coast/cruise w/ 4.10 around 45~50mpH I would have to be in 5th gear.....everyone keeps saying there's not much of a diff, but there is.....I'll be making some drive video's.
Spin can chime in, Spin can even drive it.....80 to 130 was effordless, my speedometer needle was sweeping faster than the rpm needle and I didnt realize how fast the car got to 130+...........w/4.10, pass 110 I had to floor it & shift
I love it, and it's exactly what I wanted out of the car, a happy medium
You guys do remember what happened at the end of Chicken Little? The sky did fall down
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From: Bethesda MD
Sorry, that does not make sense, nor does it support your results that showed a 9 - 13% variance. I'm not doubting what you saw on your speedo, it could have be incorrect, but 3.90s to 4.10 is a 5% difference. Here's the math done long hand:
If you take the ratio of the gears times the speed, you get the new speed from changing gears. The changes are pretty much linear, unless extreme tranny or axle ratios are used.
Thread Starter
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From: Bann Camp & N.Y.C.
St. Jude Donor '08
http://www.xse.com/leres/bin/gearrat...mference=84.04
you can use this chart to change rpms, mph & gears.......(tire height is 26.75)
well based on this graph and a slight margin of error on my part (not easy to see exact rpm on the cluster, this might have been what it was
4.10 @ 1,950 rpms = 66.4 mph
3.90 @ 2,095 rpms = 75.0 mph
you can use this chart to change rpms, mph & gears.......(tire height is 26.75)
well based on this graph and a slight margin of error on my part (not easy to see exact rpm on the cluster, this might have been what it was
4.10 @ 1,950 rpms = 66.4 mph
3.90 @ 2,095 rpms = 75.0 mph
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From: NJ
St. Jude Donor '05-'08
And to be frank it is not the long gap between shifts which bothers me it is the shifts where I have to make a decision to shift up to the next gear or to hold the current gear. With 4.10s I could not hold a gear as long thus I was making this decision alot. Hold the current gear or shift up just to have to shift back down in another few feet.
Either way I am losing fractions of seconds around the track, but when you throw in 2 shifts I have a greater chance of making a mistake, I unblance the car ore often and I have more wear and tear on the drivetrain. IF I do not shift then the engine internals heat up because I am at top RPM for a longer period of time.
Finding a gear that I can run out and not have to make a shift unless it is a long straight away IMHO gives me an advantage....
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Melting Slicks
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From: NJ..."the way I saw it, everyone takes a beating sometimes."
If I knew I was going to make the shift with either gear set then I would take the 4.10s.
And to be frank it is not the long gap between shifts which bothers me it is the shifts where I have to make a decision to shift up to the next gear or to hold the current gear. With 4.10s I could not hold a gear as long thus I was making this decision alot. Hold the current gear or shift up just to have to shift back down in another few feet.
Either way I am losing fractions of seconds around the track, but when you throw in 2 shifts I have a greater chance of making a mistake, I unblance the car ore often and I have more wear and tear on the drivetrain. IF I do not shift then the engine internals heat up because I am at top RPM for a longer period of time.
Finding a gear that I can run out and not have to make a shift unless it is a long straight away IMHO gives me an advantage....
And to be frank it is not the long gap between shifts which bothers me it is the shifts where I have to make a decision to shift up to the next gear or to hold the current gear. With 4.10s I could not hold a gear as long thus I was making this decision alot. Hold the current gear or shift up just to have to shift back down in another few feet.
Either way I am losing fractions of seconds around the track, but when you throw in 2 shifts I have a greater chance of making a mistake, I unblance the car ore often and I have more wear and tear on the drivetrain. IF I do not shift then the engine internals heat up because I am at top RPM for a longer period of time.
Finding a gear that I can run out and not have to make a shift unless it is a long straight away IMHO gives me an advantage....
I'll take your word on gear ratio around the track and I agree with you on the frequency of shifts. I'm refering to a long straight away, full throttle run. This is where C6DVL apparently has his most fun. At high speeds, running against the exotics. Yet he is basing his gear decision on a few unsatisfying 1/4 races. A venue in which he openly admits to not being too interested in.
Last edited by k0bun; Apr 12, 2008 at 06:09 PM.
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From: Objects in your mirror are losing , Long Island, NY
St. Jude Donor '08
, the 4.10 geared ride will beat the 3.90..However, in your defense with your style of driving and gas concious discipline
, 3.90's, would be appropriate.
Last edited by welcome2try; Apr 12, 2008 at 06:57 PM.
Thread Starter
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From: Bann Camp & N.Y.C.
St. Jude Donor '08
100%! 4.10's would be faster in all gears. Take two ls2's or ls3's of identical mods, one with 3.90's the other 4.10's. Hypothetically identical driver skills invloved, do a 0-180 run, the 4.10 geared car hands down will win every time. Shift faster into the next gear rev faster, simple physics. And yes Ed both 3.90and 4.10 geared cars with sticky tirez identical mods and drivers, and all the stars and heavens lined up correctly same DA , the 4.10 geared ride will beat the 3.90..
However, in your defense with your style of driving and gas concious discipline, 3.90's, would be appropriate.
, the 4.10 geared ride will beat the 3.90..However, in your defense with your style of driving and gas concious discipline
, 3.90's, would be appropriate.
stop by at cunningham park thurs evening, we'll go for a drive or I'll see you on the NYC to Philly midnight run 
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Its not a corvette observation. Its with ALL cars.
Cartek's H/C record for a 4.10 geared car is 10.56 @130mph, Dave told me this week. Feel free to get a better 3.90 run.
My recopmendation for all street H/C cars is 4.10's based on 50+ geared corvettes I have tuned. Yes, I can question anyone's SOTP observation with a single car. That is a PERFORMANCE observation with no mileage whining or OCD about RPM's on the highway. If those things are bettered with 3.90's get them. Its a compromise giving up the rate a car winds through each gear.
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Less rpm's on the hiway is confirmed. Great.
Every car i ever drove and swapped to steeper gears it accelerated faster and I drove my car with 3.42's and with 4.10's and it was faster with 4.10's. Hmmmm something must happen when you get to the 3.90 line.