R200 4.11 or 3.90 which should I use??

[Guest Xtinc]

I have a '72 240Z w/ L24 and will be installing a later ZX 5 speed trans. Should I go with the 4.11 or the 3.90 gear diff? I don't know a whole lot about the gear ratio thing - would I see a big difference between the two? I've never driven anything, but the stock 4sp and rear end.

 

Thanks

[threeZguy]

Here is a link that may help you out a little.

 

http://www.geocities.com/z_design_studio/

 

.......Chris

[Lockjaw]

If you have access to both, I would get the 4.11. The ZX trans has plenty of overdrive, and the first gear ratio is taller than your 4 speed, so you need the extra gear in the back.

 

I bet it perks up pretty good with the 4.11's/

[Guest mck2]

I can't get a 4.11 into http://www.geocities.com/z_design_studio/

so I ran it through my spreadsheet.

70-79 have a .864 5th gear.

1980 have a .775 5th gear.

81-83 have a .745 5th gear.

Makes a difference! So does tire size! I like the 3.90 with my 81 trans and 225/50R14 tires on street, hwy, and track. 129mph@5500, 70mph@3000 The 4.11 gives faster acceleration and 122mph@5500, 67mph@3000. About the same but 3.9 is more available and cheaper. You can get a lot out of a decent R180 or R160. You dont HAVE to have a R200. Save $100. If I had a .864 5th I'd get the 4.11 because the 3.90 is 101mph@5500, 61mph@3000. BTW bigger diameter tires will raise the speed and slow the acceleration. HTH

[RB30-ZED]

Just highlight the ratio in the box and delete, then type in what ever you like.

Steven

[KG78Z]

I have used both and if all you have changed is the transmission then I would definatly go with the 4.11. I am useing it now and it pulls through all gears, to pass someone you do not need to change out of 5th, which I had to with the 3.9.

KG78Z