Auto diff upgrade for someone NOT willing to lose cruise control

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BamaCoupe
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Auto diff upgrade for someone NOT willing to lose cruise control

Postby BamaCoupe » Thu Aug 06, 2020 7:16 pm

I've been a member at NICO for over ten years with my previous 2008 3.5 Altima Coupe I bought in June of 2008 and after 13 years of ownership I decided to go from the original owner of a poor mans G to the REAL G. I don't know if there is much action here, much like info for the Altima for so DUMB and I'll say DUMB again reason all the activity moved to a facebook group. Well I like forums and I don't want to hire a facebook interpreter... I lost my connection years ago because I'm not willing to do facebook and I don't get it's format. I'm not that old either... maybe now I am but then and now it doesn't make much since to me. I'm now forty.

All that to say I've done a lot of googling with no apparent answer, all somewhat close answers coming from "MyG37" and nothing deficient there. I want to upgrade my Differential but I'm not willing to do the G37 manual sport LSD and put 3.9 final gears from a frontier in it because I'm not willing to sacrifice cruse control. I've heard the Vert's have a 3.9 diff as well but I don't know if that the manual (the problem with using manual diff's is losing cruse control) or if it's all Vert's have the 3.9 gear, I know they weight about 300lbs heavier so maybe. I'm in a 7-speed Automatic or I would never own it, all my cars are a daily. Even My previous Altima coupe after thirteen years only had 80k. Why would I spitf through gears when a car will do it for me on an auto (I'll agrue with the other side on my previous CVT), I'm not a professional race car driver nor is 99% of the drivers out there so to make a manual faster you need to be a professional race car driver to be faster than an Auto. I'm sure I'm going to get the dogs barring on this but on my current stock setup 3.3 final gear, I want to lighten its step. Anyone left out there at NICO?


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BamaCoupe
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby BamaCoupe » Wed Aug 19, 2020 12:17 pm

I'm sorry I did type the OP drunk so I rambled a bit but come on...? Any answer to my main question, does a Vert's have the 3.9 diff? Do I need to join MyG37 to get answers?

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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby AZhitman » Wed Aug 19, 2020 12:27 pm

Aside from the slight incoherence, I'm not sure why changing your differential would affect cruise control.

I'll have to do a little more research on the G37 convertible - but I believe that is correct that they have a 3.90 rear end ratio.

DFW2011M56S
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby DFW2011M56S » Mon Aug 24, 2020 3:50 am

AZhitman wrote:
Wed Aug 19, 2020 12:27 pm
Aside from the slight incoherence, I'm not sure why changing your differential would affect cruise control.

I'll have to do a little more research on the G37 convertible - but I believe that is correct that they have a 3.90 rear end ratio.
Changing the gear ratio will cause the cruise to stop working. The output speed sensor in the transmission and the wheel speed sensors will not agree with the gear change and confuse the system.

That being said my 07 G35 3.5HR/Automatic Sedan has a factory 3.91 rear gear. Same center section as a G37 since they are both V36 chassis. Its a fun gear with the 5spd auto but it spins 3,000 rpm @ 70 on the highway.

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BamaCoupe
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby BamaCoupe » Sat Jan 02, 2021 10:08 pm

DFW2011M56S wrote:
Mon Aug 24, 2020 3:50 am
AZhitman wrote:
Wed Aug 19, 2020 12:27 pm
Aside from the slight incoherence, I'm not sure why changing your differential would affect cruise control.

I'll have to do a little more research on the G37 convertible - but I believe that is correct that they have a 3.90 rear end ratio.
Changing the gear ratio will cause the cruise to stop working. The output speed sensor in the transmission and the wheel speed sensors will not agree with the gear change and confuse the system.

That being said my 07 G35 3.5HR/Automatic Sedan has a factory 3.91 rear gear. Same center section as a G37 since they are both V36 chassis. Its a fun gear with the 5spd auto but it spins 3,000 rpm @ 70 on the highway.
Does your car have a Diff swap or is that what comes in them? I will say my parents had a 07 G35 (V36 as well) sedan and I will say it felt lighter on its feet and a lot better throttle response in all gears. My car just seems geared wrong, doesn't matter if I get on it or driving in traffic and always too quick to shift up, slow in shifting (it's not going to fix that) but always feels like my cars in a gear or two higher than it should be. Thanks for the replies!

DFW2011M56S
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby DFW2011M56S » Mon Jan 11, 2021 11:46 pm

Factory rear gear was a 3.91. Does your car have a 7spd auto? The 5spd auto never feels like that to me unless you are coasting around town. On the other hand the 7spd in my M56S always felt like it was in too tall of a gear for the speed even in sport mode. At 50 mph I would almost have to floor the car to get it to downshift to climb a slight incline.

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BamaCoupe
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby BamaCoupe » Fri Jan 15, 2021 4:22 pm

DFW2011M56S wrote:
Mon Jan 11, 2021 11:46 pm
Factory rear gear was a 3.91. Does your car have a 7spd auto? The 5spd auto never feels like that to me unless you are coasting around town. On the other hand the 7spd in my M56S always felt like it was in too tall of a gear for the speed even in sport mode. At 50 mph I would almost have to floor the car to get it to downshift to climb a slight incline.
Yes, 7 speed auto here and everything you said. Always feels like it's in a gear or two too high and slow to downshift. My parents 2007 G35 Sedan with the 3.5HR and 5-speed auto felt faster than my 2011 G37 Coupe with the 7-speed auto. DS mode feels no different than D on my car.

DFW2011M56S
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby DFW2011M56S » Sun Jan 17, 2021 9:38 pm

Not knocking your G37 but the 07 G35 sedan probably is a quicker car. With 170K on the clock mine went low 13.4s and a couple of 13.38s on stock sized Sumitomo HTRs with 22 psi in the rear tires. Dead consistent 13.4s @ 103-104 mph. Car was stock save for K&N drop in filters, HPS post maf intake tubes and a 2° timing advance. Had I done the burnout mod to let me launch it hard with the converter stalled up around 3,000 rpm and been on drag radials to hook it certainly would have hit high 12s. Certainly would have been there for sure with those mods and the Stillen underdrive crank pulley. Has run a 12.8 @ 108 on the same Sumitomos with the DC Sports headers, Z1 highflow cats, custom 2.5" exhaust and 2.75" maf housings with the custom CAI and Uprev tune.

DFW2011M56S
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby DFW2011M56S » Sun Jan 17, 2021 9:42 pm

With 210k on the odometer it put down 326 hp and 282 tq to the tires on a Dynojet. Cam phasing adjustments alone gave me more than 20 ft/lbs of torque across a broad rpm band.

DFW2011M56S
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Re: Auto diff upgrade for someone NOT willing to lose cruise control

Postby DFW2011M56S » Sun Jan 17, 2021 9:47 pm

The DC Sport headers get knocked by alot of people for lack of peak HP gains. That being said their merge collector, equal length design with the longer primaries than the stock manifolds really helped broaden the torque curve through most of the powerband especially when paired with the 2.5" X-pipe. Headers, Exhaust, Tuning with the Cam phasing and the larger MAF ends woke this car up like no other. When I first tested it after the tuning the car was spinning the tires at 60+ MPH.


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