Review 4.083 Final Drive on the 6MT Sedan
05-10-2017, 08:00 AM
#16
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Here's some perspective... if I had opportunity to experience a 6MT G37 with a 4.083 gear swap five years ago after buying my car, every single dime of future mods would have been saved up to do this first. Everything would have taken a back seat... sways, exhaust, intake, pedal, STS, wheels, all the little visual mods. Everything.
Sounds like hyperbole, I know. And after driving my buddy's Tesla P100d, my car seemed sluggish. But not anymore. (Until I drive his Tesla again, damn it. LOL)
Last edited by Rochester; 05-10-2017 at 08:06 AM.
05-10-2017, 08:18 AM
#19
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Suppose I should start researching oil coolers.Let's make a more realistic comparison. His previous car was a STi, stock with the upgraded Sport Exhaust. And my G now has enough low end grunt to be very competitive.
Last edited by Rochester; 05-10-2017 at 06:18 PM.
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Daddy Fat Sacs (05-10-2017)
05-10-2017, 10:00 AM
#22
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Not that I can tell. Can't think of why there would be added noise.
However, take that with a grain of salt. For one, between the full FI exhaust and the Z1 Transmission mount, the car is plenty loud. Add to that the fact that I'm deaf in one ear... I'm hardly an expert on car noises.
However, take that with a grain of salt. For one, between the full FI exhaust and the Z1 Transmission mount, the car is plenty loud. Add to that the fact that I'm deaf in one ear... I'm hardly an expert on car noises.
05-10-2017, 10:16 AM
#24
experienced it in my other car after the swap... maybe I should have used the term gear whine instead of noise..
noise indicates an issue from improper installation as Dfatsacs noted above..
the difference was significant enough to notice over the exhaust... not complaining.. it actually sounds pretty good..
noise indicates an issue from improper installation as Dfatsacs noted above..
the difference was significant enough to notice over the exhaust... not complaining.. it actually sounds pretty good..
05-10-2017, 10:20 AM
#25
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I imagine warnings like that are what keep your average, everyday car enthusiast away from mods like this.My mechanic talked to me at length about the install afterwards. I've been going to him for about a decade now. When he originally opened his shop, he was intending to create a Street/Pro reputation. The realities of running a business ended up with him doing more basic repairs than mods, so he enjoys it when I bring him my car. But I certainly respect his skills, something which was compounded hugely with this last project.
The tolerances in fitment with these parts are so razor thin, either you nail the install, or it will fail right away. I don't think there's a whole lot of variation between those two results. IDK... all cars are different, and I'm no expert.
Insofar as I can tell, I have no added noise from the back end. No "whirring" or "spinning" sounds, nothing that's untoward or unusual. That doesn't mean things won't go "Boom!" someday. **** happens. I blew two OEM rear ends in a TransAm 30 years ago, and it's not a pleasant experience.
As for the diff bushings... at the last minute before the install, I clued into the recommendation that you flip the halves on the side bushings for the G, opposite the Whiteline instructions, which were written for the 350Z. I don't have any added vibrations at all, after the bushings. Just a very solid feeling that wasn't there before. Very pleasantly surprised about that, too.
Last edited by Rochester; 05-10-2017 at 10:39 AM.
05-10-2017, 10:30 AM
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Here's a pic he sent me during the project. The paint is a technique to gauge how the pinion connects to the teeth in the ring, and there's a particular wear pattern you're supposed to achieve. Apparently this is exactly what you want.
05-11-2017, 12:34 AM
#28
Hey 4DRZ... which gear do you live in the most on the track? I'm guessing 3rd. Wish I could show you what third gear is like now. But I hear you when you talk about proper road track behavior keeping the revs at the top of the power band. That makes a whole lot of sense.
I'm still not sure your gears make sense for me for track days if you are noticing the biggest differences at low and mid rpms. I am eager to try out my new Intakes, Intake Plenum, and Tune from Z1 on the track since most of my gains are in the upper rpm ranges.
Your numbers are skewed a little as you have the drive ratio on tranny 2 at 3.357 which is for the 7at, however we are discussing 6mt and should be 3.692.
On serious note, if you havent already you may want to look at an oil cooler now. I know you dont drive your car all that often or far, but since you'll be running at higher RPM's in all gears and our cars run hot out the factory, something I would seriously look at.
On serious note, if you havent already you may want to look at an oil cooler now. I know you dont drive your car all that often or far, but since you'll be running at higher RPM's in all gears and our cars run hot out the factory, something I would seriously look at.
An oil cooler is complete overkill for street driving in this car. My 2011 370Z did not even see rising oil temps until I was on track for about 20 minutes. If Rochester were planning to track the car, then definitely consider an oil cooler. But with his low street mileage it should not ever be necessary.
05-11-2017, 07:08 AM
#29
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Although I suspect it will, I really can't answer that question. What I can do is recommend you come to the August meet-up and I'll let you see for yourself. It's a long drive from WI, but still do-able. And IMO it would be a worthwhile thing while you are where you are with your car as a hobby.
https://www.myg37.com/forums/upcomin...mmer-meet.html
Then again... letting you see for yourself how it applies to your purposes means high-speed, WOT in the upper gears... er-r-r.
The only thing I can say with 100% confidence, is that this is the best most significant power mod for daily driving that you can do to this car while still NA. And by quite a few factors over any I/E mods. While I'm becoming more used to it every day, it's such a change that I suspect I will always appreciate it. But all I'm doing is driving the girls to field hockey games, with occasional runs for lunch. None of that compares to what you need out of the car for a road track event.
On a side note, at a game last night, there was a Ferrari F430 in the high school parking lot, looking insanely out-of-place in this predominately blue-collar neighborhood. If ever you want to look at your little G Sedan as an average, everyday four-door, park it next to a Ferrari.
After Fat Sac suggested it, I started some light reading, and came away with the same opinion.
https://www.myg37.com/forums/upcomin...mmer-meet.html
Then again... letting you see for yourself how it applies to your purposes means high-speed, WOT in the upper gears... er-r-r.
The only thing I can say with 100% confidence, is that this is the best most significant power mod for daily driving that you can do to this car while still NA. And by quite a few factors over any I/E mods. While I'm becoming more used to it every day, it's such a change that I suspect I will always appreciate it. But all I'm doing is driving the girls to field hockey games, with occasional runs for lunch. None of that compares to what you need out of the car for a road track event.
On a side note, at a game last night, there was a Ferrari F430 in the high school parking lot, looking insanely out-of-place in this predominately blue-collar neighborhood. If ever you want to look at your little G Sedan as an average, everyday four-door, park it next to a Ferrari.
After Fat Sac suggested it, I started some light reading, and came away with the same opinion.
Last edited by Rochester; 05-11-2017 at 07:53 AM.
05-11-2017, 09:49 AM
#30
It took me a minute again before I realized the confusion. You said:
I was already looking at data and a graph on it and posted it saying bla *insert my post*. The graph showed (in red) you would be around 7100 RPMs in 5th gear at 140mph with a 4.083 final in and a 6-speed mani box; the target speed you were looking for. Though this data was for 285 width tires, it only bumps up your RPMs by like 75ish for 275 tires.
The other transmission on that data table (in blue) is a stock geared and final 7-speed auto. Like I said I was literally at the time of your post looking at the data because I was thinking about what Rochester had reviewed (a good one at that) and was considering not switching out my final because as you can see the stock auto is still geared a tad quicker then a 4.083 mani in the lower gears. But I digress.
It was not meant to be a comparison (for you) but I will gladly pull the numbers for you guys if you like. It was meant to give a quick visual of the speed vs. RPM of the 4.083 on a mani box. The fact the other transmission was on there and confused everyone was only because honestly I was pulling data for myself at the time, thought the visual would help, and just screen shot it and posted; again: apologies.
And yes 4DRZ, the max MPH for the 4.083 final mani is higher in the first three gears and lower in 4th-6th then the auto's stock gear box. The auto has a quicker stock gear box through the first three gears, the math is correct. Ask Nissan why they did it that way.
Nice. Thanks! He brought up a good point about losing top end speed. On my local track (Road America) I think I would probably hit about 140mph at the end of 3 of the straights. (I am guessing as I have not driven it this year with the latest HP upgrades) I cannot imagine this would affect me as I have never even used 6th gear on this track yet, but I wonder how much top end I lose.
On a track you are usually trying to stay right toward the top of the powerband/rpm range. If you are noticing a large difference in acceleration mostly at lower and mid rpms, I wonder if this would be a good mod for my track days.
On a track you are usually trying to stay right toward the top of the powerband/rpm range. If you are noticing a large difference in acceleration mostly at lower and mid rpms, I wonder if this would be a good mod for my track days.
The other transmission on that data table (in blue) is a stock geared and final 7-speed auto. Like I said I was literally at the time of your post looking at the data because I was thinking about what Rochester had reviewed (a good one at that) and was considering not switching out my final because as you can see the stock auto is still geared a tad quicker then a 4.083 mani in the lower gears. But I digress.
It was not meant to be a comparison (for you) but I will gladly pull the numbers for you guys if you like. It was meant to give a quick visual of the speed vs. RPM of the 4.083 on a mani box. The fact the other transmission was on there and confused everyone was only because honestly I was pulling data for myself at the time, thought the visual would help, and just screen shot it and posted; again: apologies.
And yes 4DRZ, the max MPH for the 4.083 final mani is higher in the first three gears and lower in 4th-6th then the auto's stock gear box. The auto has a quicker stock gear box through the first three gears, the math is correct. Ask Nissan why they did it that way.
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Rochester (05-11-2017)