4.08 Final Drive = OMG
04-26-2010, 02:09 AM
#47
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neverbonestock - was a mathing pinion included with the gear or did you just use the stock pinion? Any part numbers? I've been looking for gearing information. Thanks for posting this review.
04-26-2010, 02:25 AM
#48
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This is 1/2 the problem ... 90% of what you see on forums is bench racing... basically kids sitting around comparing how much HP they have on paper by adding up all the supposed bolt on power gains and theorizing how things work ....
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
04-26-2010, 03:11 AM
#50
Registered User
04-26-2010, 03:18 AM
#51
This is 1/2 the problem ... 90% of what you see on forums is bench racing... basically kids sitting around comparing how much HP they have on paper by adding up all the supposed bolt on power gains and theorizing how things work ....
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
And maybe you should check out what these "bench racing kids" have been doing to their cars. It'll make you feel like a baby in a big boy's park.
04-26-2010, 04:13 AM
#52
Administrator
NBS, you might want to include questions you already answered in your first post, I see them being asked a few dozen more time
Things like: Price + Install, Where you ordered from, What it came with, etc.. Basically a proper review lol
Things like: Price + Install, Where you ordered from, What it came with, etc.. Basically a proper review lol
04-26-2010, 06:07 AM
#53
Registered User
so does it or does it not work with autos? I think I read the input shaft on the auto is slightly different. I don't know how that would affect the installation of the pinion gear. Also, how many teeth on the stock ring and pinion vs the 4.08's?
04-26-2010, 06:25 AM
#54
I was just quoting what others have said on other forums. Much like yourself, I like to do research on topics that I find interesting. 
My350z and g35driver have been sources that I've frequently turned to for explanations, experiences, and etc. Those guys simply have had more time to try different things with their cars.
From personal experience, 0-7k comes very fast on a TTed G37 in first gear. The car becomes very tail happy, especially on stock tires. I think a 4.08 gear will only exasperate the traction problem. Plus, I can only picture the MPG getting worse as a result. I guess the same will apply to a supercharged G37.
I picture this mod to be more beneficial for N/A owners.
My350z and g35driver have been sources that I've frequently turned to for explanations, experiences, and etc. Those guys simply have had more time to try different things with their cars. From personal experience, 0-7k comes very fast on a TTed G37 in first gear. The car becomes very tail happy, especially on stock tires. I think a 4.08 gear will only exasperate the traction problem. Plus, I can only picture the MPG getting worse as a result. I guess the same will apply to a supercharged G37.
I picture this mod to be more beneficial for N/A owners.
This is 1/2 the problem ... 90% of what you see on forums is bench racing... basically kids sitting around comparing how much HP they have on paper by adding up all the supposed bolt on power gains and theorizing how things work ....
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
The main purpose of bumping up the gear ratio is to increase torque multiplication. By upping the gear ratio you cause the engine to turn more times for each rotation of the wheels - This is the equivalent of increasing the length of a lever arm (longer lever means longer movement for the same rotation) which gives you more force. This doesn't change the amount of torque generated by the engine, but it does change the amount delivered to the ground (think why you get crazy high numbers on a dyno unless you use a gear that has a final drive ratio of 1:1)
So it's real simple, unless you get silly with the ratios, if you are not traction limited you will almost always increase acceleration by increasing gear ratios regardless of if your car is supercharged, turbocharged, N/A, or NOSed, and reduce acceleration by decreasing the ratios (but cruise at lower rpm so probably get better MPG).
BTW: what does my350Z.com say about NOS and gears
Check out wikipedia for a pretty good explanation : Gear ratio - Wikipedia, the free encyclopedia
--C
Did you even read what my post said? Everyone here understand the simple effect of increasing the gear ratio. You belittle others with "bench racing", yet you speak of unlimited traction? Of course, a high final drive will result in higher acceleration. But some of us are already thinking beyond that fact. For FI applications, there is already sufficient torque to spin out the tires and not have enough traction. Increasing the ratio will only make this problem worse. You'd be smoking the tires in 1st gear and not going anywhere. So maybe the "bench racers" are thinking ahead of you.
And maybe you should check out what these "bench racing kids" have been doing to their cars. It'll make you feel like a baby in a big boy's park.
And maybe you should check out what these "bench racing kids" have been doing to their cars. It'll make you feel like a baby in a big boy's park.
Wooow there killer! Reevaluate yourself, he wasn't insulting you directly. He simply pointed out one of the downfalls of the forums and you got all offended by it. I didn't see him belittling you anywhere, however your comments were pushing it.
04-26-2010, 06:44 AM
#55
This is a subject I've looked into a little. Word is the carrier assembly is different between the autos and manuals. The gears fit the larger housing (manual) but not the smaller one (auto). Meaning you would have to swap out the whole rearend. There is also talk about the cruise control not working after the swap for the auto but either no one knows why are they just aren't saying. A lot of this is correct information for the G35/350Z from a few years ago but I don't know if it's true for the G37/370Z or if it's just info carried forward.
I would do this mod in a heartbeat if it didn't effect cruise control. If I disabled cruise control on Her car I don't think she would ever let me touch it again.
This would cost me over two grand to do this mod as well. New or used carrier assembly from a manual, gears and parts, labor for install, and a new LSD. The aftermarket LSD's start at like a grand. I'd do almost all the labor except setting the gears. One of the other sites had a great post showing all the differentials available and the pros and cons of each but I can't find it again.
04-26-2010, 06:58 AM
#56
I still have not found the thread I was looking for but here is a site that has a number of the different differentials listed.
Z-1 Performance Automotive Services Inc.
Z-1 Performance Automotive Services Inc.
04-26-2010, 09:47 AM
#58
Registered User
A close gear ratio (i.e. 3.3:1) improves top speed but limits acceleration. This is good for gas mileage and engine wear. A wide gear ratio limits top speed but improves acceleration. This is more taxing on the engine as it faces a little more resistance from the diff.
The 4.08 can be found here.
GTM Motorsports
FINAL DRIVE - AXLES RING AND PINION 4.083 FINAL DRIVE
The 4.08 can be found here.
GTM Motorsports
FINAL DRIVE - AXLES RING AND PINION 4.083 FINAL DRIVE
04-26-2010, 10:01 AM
#59
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Of course, a high final drive will result in higher acceleration. But some of us are already thinking beyond that fact. For FI applications, there is already sufficient torque to spin out the tires and not have enough traction. Increasing the ratio will only make this problem worse. You'd be smoking the tires in 1st gear and not going anywhere. So maybe the "bench racers" are thinking ahead of you.
And maybe you should check out what these "bench racing kids" have been doing to their cars. It'll make you feel like a baby in a big boy's park.
Anyway - It seems maybe there was some misunderstanding .. my post was just meant to educate on gear ratios, it seems that this is a relatively new topic for G/Z owners but it's one that I have a lot of personal experience with.
Happy Motoring
-C
Last edited by planoyzfr1; 04-26-2010 at 10:08 AM.
04-26-2010, 11:20 AM
#60
Administrator
God why all the tension in this thread? Relax fellas