G37 Sedan

Brand New to the 2012 G37 6mt

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Old Aug 8, 2012 | 05:33 PM
  #16  
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In reference to the clutch pedal spring, I've had the weaker spring in mine now for just shy of 8 months. I didn't like the no spring approach as that left too much slop with the pedal off the floor.

A local friend with a recently purchased nismo said he had no problem feeling the clutch (previous 350z owner).

Today, I decided to put the stock spring back in and give it a few days to see what I think. So far I'm hating it. While the stock spring makes the initial pedal effort noticeably less, it has a very numb feeling at the most important spot, the start of the engagement point [off the floor]. If the spring was a bit shorter, its effect would be felt after engagement point. I have a long commute tomorrow, but will take the weaker spring with and a pair of needle nose pliers. 30 seconds is all it takes to swap.
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Old Aug 8, 2012 | 06:03 PM
  #17  
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Congrats, it's a beauty!

Another white 6MT, saw a couple already in my office's parking lot, get me wonder how whites are 6MT's, blacks are X's. Have they ever made other color other than black and while for '12?
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Old Aug 8, 2012 | 06:06 PM
  #18  
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Graphite shadow here, but that was a special order. Most I've seen are black too. Saw one sedan in silver (liquid platinum) while test driving.
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Old Aug 8, 2012 | 10:10 PM
  #19  
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I've been driving a stick for almost 35 years - all performance cars. I realized after a few days with the 6MT that if you shift 1st to 2nd between 4k and 5K RPMs when driving "normal", the shift is very smooth. Might seem a little high for normal driving, but this is a higher revving engine than a chevy 350 :-) No need for any mods. If you try and shift lower RPM, say 3k - 4K, you have to just let the engine RPM come down a little before letting the clutch out, or let the clutch out a little slower. (might take about 1/2 to a second ) The goal of this approach is to let the engine rpm drop about 1K so it matches the speed the car is going so you dont feel that little "buck". Depending on how long it takes YOU to shift, it will be easier at a slightly higher or lower RPM. When shifting under heavy acceleration all gears are easy to shift smooth in this car. It will just take a little practice and watching the tach at first to get a feel for when to let the clutch out when driving "normal".
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Old Aug 8, 2012 | 10:48 PM
  #20  
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Jealous

It's beautiful. I thought about the stick, but the wife and kid get very vocal when I'm not shifting perfectly... they're like a warning system for my spazzy left leg. I'm sure you'll get much better very quickly!
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Old Aug 8, 2012 | 10:53 PM
  #21  
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Originally Posted by jayg37coupe6MT
I've been driving a stick for almost 35 years - all performance cars. I realized after a few days with the 6MT that if you shift 1st to 2nd between 4k and 5K RPMs when driving "normal", the shift is very smooth. Might seem a little high for normal driving, but this is a higher revving engine than a chevy 350 :-) No need for any mods. If you try and shift lower RPM, say 3k - 4K, you have to just let the engine RPM come down a little before letting the clutch out, or let the clutch out a little slower. (might take about 1/2 to a second ) The goal of this approach is to let the engine rpm drop about 1K so it matches the speed the car is going so you dont feel that little "buck". Depending on how long it takes YOU to shift, it will be easier at a slightly higher or lower RPM. When shifting under heavy acceleration all gears are easy to shift smooth in this car. It will just take a little practice and watching the tach at first to get a feel for when to let the clutch out when driving "normal".
Thanks for the heads up.

I've typically been shifting 4.2-4.5 and going in 2nd at 3k. Should I wait longer? Where are you engaging 2nd after revving 1st to 5k?
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Old Aug 8, 2012 | 11:03 PM
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I think the difference between 1 & 2 is more than 1K rpm. Probably closer to 1.5K.

Nate, try this, go 30 mph in 1st, note the rpm. Then do 30 mph in 2nd. On my car 30 mph in 2nd is right at 2Krpm. So I'm guessing first would be more like 3500 or so.

In fact, if you're shifting at higher revs, you might need to go up to 40 mph to determine the difference. But you get the idea, drive at the same speed in different gears and note the rpms, then you'll know what to shoot for.

You'll know you have it matched properly when the shift is smooth.

Edit1: (someone correct me if i'm wrong and justify why). This rpm difference between gears will be the same regardless of engine rpm. This is because the gear ratios are fixed and don't change based on load or other factors (this is not an auto or a cvt trans). So shifting at redline, you'll still need to drop it that 1500 or so rpm before engaging clutch for the next gear.

Edit2: Edit1 above is incorrect. See attached excel file which shows (based on (RPM x Tire Diameter)/(Final Drive Ratio x 336) = MPH) that vehicle speed is a function of both engine rpm and inversely proportional to gear ratio. Based on the calculations, if you shift from 1st to 2nd at redline (7250 rpm), you'll need to let the rpms drop about 4500 before engaging 2nd.
Attached Files
File Type: zip
rpm_speed.zip (9.1 KB, 12 views)

Last edited by JSolo; Aug 9, 2012 at 01:30 AM.
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Old Aug 9, 2012 | 02:17 AM
  #23  
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Originally Posted by Jsolo
I think the difference between 1 & 2 is more than 1K rpm. Probably closer to 1.5K.

Nate, try this, go 30 mph in 1st, note the rpm. Then do 30 mph in 2nd. On my car 30 mph in 2nd is right at 2Krpm. So I'm guessing first would be more like 3500 or so.

In fact, if you're shifting at higher revs, you might need to go up to 40 mph to determine the difference. But you get the idea, drive at the same speed in different gears and note the rpms, then you'll know what to shoot for.

You'll know you have it matched properly when the shift is smooth.

Edit1: (someone correct me if i'm wrong and justify why). This rpm difference between gears will be the same regardless of engine rpm. This is because the gear ratios are fixed and don't change based on load or other factors (this is not an auto or a cvt trans). So shifting at redline, you'll still need to drop it that 1500 or so rpm before engaging clutch for the next gear.

Edit2: Edit1 above is incorrect. See attached excel file which shows (based on (RPM x Tire Diameter)/(Final Drive Ratio x 336) = MPH) that vehicle speed is a function of both engine rpm and inversely proportional to gear ratio. Based on the calculations, if you shift from 1st to 2nd at redline (7250 rpm), you'll need to let the rpms drop about 4500 before engaging 2nd.
This is fantastic for an engineer like me

How did you find out this info?
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Old Aug 9, 2012 | 02:35 AM
  #24  
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^^I was in error yet again, it's 20 mph @ 2K rpm in 2nd!@#

A bit of googling, a formula, some excel basics, etc. Then come to find someone already did the dirty work. My background is EE, but mechanical gears are similar in some respects.

http://f-body.org/gears/

See these pdf's - http://db.tt/l8QfAWtI

20 mph = 3600rpm in 1st
20 mph = 2200rpm in 2nd, delta of 1400rpm.

The numbers I plugged in there are based on the 18" 245/45/18 tire size on the rear of the sport sedan. I believe the coupe is similar in diameter although it's a 19". Also, obviously the calculations are theoretical, not accounting for friction and other losses. Still, they give a reasonable baseline.
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Old Aug 9, 2012 | 02:41 AM
  #25  
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Originally Posted by Jsolo
^^I was in error yet again, it's 20 mph @ 2K rpm in 2nd!@#

A bit of googling, a formula, some excel basics, etc. Then come to find someone already did the dirty work. My background is EE, but mechanical gears are similar in some respects.

http://f-body.org/gears/

See these pdf's - http://db.tt/l8QfAWtI

20 mph = 3600rpm in 1st
20 mph = 2200rpm in 2nd, delta of 1400rpm.

The numbers I plugged in there are based on the 18" 245/45/18 tire size on the rear of the sport sedan. I believe the coupe is similar in diameter although it's a 19". Also, obviously the calculations are theoretical, not accounting for friction and other losses. Still, they give a reasonable baseline.
I'm EE as well. I've have to try this out tomorrow. Thanks!
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Old Aug 9, 2012 | 07:43 AM
  #26  
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Welcome to the G community! Looks like you got a very clean G. Hope your getting through the gears nicely.
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Old Aug 9, 2012 | 08:25 AM
  #27  
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On the 6MT, there's this sweet-spot between 2nd and 3rd gear. And it's in the mid-range somewhere, like 4K, where you can shift really quickly between the two gears without any momentary hesitation what-so-ever. If you've ever driven an AT with a dual clutch... that's what it feels like. The perfect shift, but with all four limbs engaged. It's also not there at WOT, but just below that when you're accelerating aggressively.

If you can find it, it's a very rewarding moment. Every time that happens, I get the biggest smile.
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Old Aug 9, 2012 | 10:50 AM
  #28  
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Nice ride! I just picked up the exact same car last month, but I have the midnight grill/rear spoiler combo.

This is my 4th Infiniti with 6MT (04 coupe, 06 coupe, 08 sedan) and I still have trouble sometimes shifting smoothly from 1-2. Like almost everyone says, either take it really easy or punch it. This is not an easy car to drive, but I'll take it over an auto any day. I had an auto for the past 1.5yrs and hated every minute of it.
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Old Aug 9, 2012 | 11:41 AM
  #29  
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Great choice. I just got a Black on Black one a week ago. Only complaint is the drivers seat. Haven't found a comfortable position yet with the bolsters on the thighs. Any suggestions?
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Old Aug 10, 2012 | 12:43 AM
  #30  
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@Nate, here's something else I found.

GearCalc

Neat little program that will show you engine rpm in terms of vehicle speed.

@mdfergus, unless you're driving aggressively in corners, i found the seats to be more comfortable with the side bolsters deflated.
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