how much better?

[MrMarcDude]

(78 280z) Hey guys, im aquiring a 4.11 rear end, and a 5 speed transmission. I was wondering how much better will my acceleration be if i go from a 3 speed auto-3.54 rear end, 70 series tires. To a 5 speed-4.11 rear end, 60 series tire? Will it be noticeable? Thanks guys! Also, whats the average going price for a r-200 4.11 rear end? I dont wanna get ripped off.

[240ZX]

Marc, The conversion you plan to do to a good one and is quite common! With the 5 spd/4:11 you will notice a significant improvement in acceleration....well worth the effort involved. As far as a typical price for an R200 differential.....somewhere around $75.00 to $200.00 depending on condition and if its an open or LSD unit. For sure you will want to do your homework on the details of the conversion. Consider replacing things like bushings, wheel bearings, U-joints, and such while you have it apart. Let us know how things transpire.

[chickenwafer]

it will be like driving a new car

[Ron Carter]

agreed, it will be a huge difference. What Transmission are you looking to run?

[First Gen Z]

It may be just an age thing but I would leave the automatic in the car. The 3n71b three speed can handle anything the 280 can dish out. Typically, automatic transmission cars turn better times at the drags because they can shift faster than us mere mortals. Anyway you look at it, with the 4:11 it will make a huge difference.

[chickenwafer]

they run faster because they are more consistant, but this is a 1970-desgined automatic. Unless it is using a shift kit, hydralic shifter or something, it won't shift that fast. And, this particular autos gears are rather weak, and so is this case, I wouldn't recommend racing with it IMO.

Dave

[MrMarcDude]

I'm getting a 5 speed from my friends 82 280zx

[chickenwafer]

make sure to use the flywheel and clutch from a 280ZX as well, not a normal 280Z. Otherwise they won't match.

[Ron Carter]

Chickenwafer, I am not sure if that is correct information. I run a Roadster clutch on my Z Race Car with a "B" box transmission and have no issue with it.

I think the correct answer is make sure that your clutch will work with the Trans you are getting.

[sblake01]

I don't think there is any difference between a 280Z clutch/flywheel and a 280ZX clutch/flyweel other than the 2+2/turbo being larger. (243mm vs 225mm)

[Ron Carter]

there are two different length collars that support the throw out bearing depending on the type of slave cylinder that you are running (early screw type [manually adjustable] vs hydraulic only [non-adjustable]) Be sure you are consistant with which set up your running and you should not have a problem.

The Diameter of the clutch does not matter other than a larger diameter clutch will give you more surface area, and larger rotating mass.