Would swaping a 7at 3.357 lsd ratio with a 3.692 6mt give me better 0-60 times?

 

It should yes, I'd love to see someone try it out. It will hurt your mpg a bit while cruising on the highway though.

 

Alot of the G35 guys do the 3.9 final gears of the 4.12 final gears. They greatly affect the acceleration.

 

sow they swap the 3.9 for a 4.12? i had a gs400 that comes with a 3.26 and installed a supra 3.76 lsd it ran 300rpm higher but gave me better off the line performance..

 

sorry I ment or. I think the G35 6mt comes with a 3.6 final drive. Most swap out for a 3.9 or 4.12

 

Can somebody explain this Sh@$. I have been hearing about this....so if you have an auto 5 or 7at, what do you need to do to get the higher gear ratio??

 

Basically, the higher the gear ratio, the faster your acceleration will be, but you will have worse MPG and lower top end.

If you have a lower gear ratio, you accelerate slower but get better MPG and higher top speed (also less stress on motor).

 

the diff on a 5at and 7at have difrent ratios he 5at has the higher one for a 7at get a 6mt diff and swap them. I am trying to get the full housing so i dont have to mess with internals.

 

We're talking the differential right? Rear gears? This "final drive ratio" term is new to me.

What are the available options out there for gear sets? 4.10 sounds a little much to me but something in the 3.7-3.9 range might get me thinking.

 

Basically, what he said. But if you still want to know more, here's a good read: HowStuffWorks "How Gear Ratios Work"

 

That's not completely true. If you spend most of the time driving in town in stop and go traffic and not at speed like on a highway, lower* (higher numerically) gears can help your mpg. Basically, you have more leverage to get going.

Also, some engines run more efficent at certain rpms. Sometimes that rpm might be a little higher, it's just the way it is.

*One more note: when talking about differential gears, the higher the number numerically, the lower the gear. Don't ask me why, I didn't invent this stuff. A 4.10 gear is considered lower than a 3.55. I went from 3.90's to 4.56's in my truck and from a 2.89 to a 3.55 in my Mustang. The lower the gear, the lower the top speed.

 

I don't follow the logic in your assessment that a lower gear ratio can ever result in higher fuel mileage. Physics says no. With a lower rear end gear ratio the car will always have to achieve higher RPM's to attain a given MPH in a given gear. It takes X amount of fuel to power the engine to a given RPM. This is a constant value. If the fuel used to achieve a certain engine RPM results in fewer revolutions of the drive wheels (which is the result of a lower rear end gear ratio) the vehicle cannot go as far using the same amount of energy (fuel). It's why your car can never get better mileage driving in 3rd gear as it does in 6th; more energy is required to drive at 60 mph in 3rd than 6th.

As to why a higher number is a "lower" rear end gear, it is because the number assigned to the gear is the number of revolutions the input shaft (drive shaft) has to make to achieve one revolution of the output shaft(s), in this case the rear axle. So with a 3.90 gear ratio, the drive shaft must turn 3.90 times to make the wheels turn one complete revolution. In a 4.56, the shaft must turn 4.56 times to spin the rear wheels once. It's "lower" because you get a lesser amount of wheel revolutions per drive shaft revolution.

 

Well, I could sit and try to explain it all out but that's not going to happen (I'm simply not that smart). I see what logic you are trying to use but there's a flaw in it somewhere. I'm talking about stop and go traffic here, not sustained speed. The lower gears help get the car moving easier, plain and simple. Gears are a form of leverage and I'm sure you can use that in the physics somewhere. This is nothing new and not a theory.

 

I'd love to hear you explain that to be honest because otherwise, you're indirectly implying that I wasted the past 5 years studying BS lol

 

No matter whether it's stop and go or highway cruising at 70 or flying down the road at top speed, the engine will always require more fuel to be burned (never ever less) to attain any speed if the gears turning have to make more turns. Period.

Whatever factor I am I am missing, please point me in the correct direction to discover it, because that will mean that I have labored all my life believing in a law of physics that is false. I can make you lots of money if you can disprove it and prove the opposite of what's considered to have been proven and accepted for hundreds of years.