4:11 vs 3:90 diff which one better on street n freeway?

[jmortensen]

5 speed will lower engine rpm about 400 rpm. Later zx non turbo's had 3:90 gears to help move the heavier car. 280z's have 3:54 gears. 4:11's are a bit quicker off the line but you have to shift sooner. Early 5 speeds have taller 1st and 2nd gears. An early 5 speed with the 4:11's would make a good light to light car. In reality, you aren't going to notice a heck of a lot of seat of the pants difference. Neither are going to help mpg with "a wild cam", what ever that is.

Disagree. The late 5 speed is what you want. The early 5 has too tall 1st and 2nd and a big arse hole in the gearing between 2nd and 3rd. Later has closer gearing and is much better suited to a motor with a big cam.

[jmortensen]

R180 4:11 with Nissan/Borg Warner T5 5-speed combo..is that good street and autocross

Again disagree. The T5 has very similar ratios to the early 5 speeds. I think they're actually wider gear spacing, but don't have such a huge hole in the 2-3 shift area. For a light car you don't really need the extra torque to launch it. Much more beneficial to have the close gearing to keep the rpms up between shifts, again especially with a big camshaft.

[Pop's Z]

FWIW, in my '73 240Z I am running a 4:11 KR180 from a 200SX combined with a later model 5-spd from an '82 Maxima. These are behind a stock '82 motor from a 280ZX. I use the car for canyon carving here in Northern Colorado. This combo is perfect for that. It has great acceleration and turns a few hundred rpms less at 70-80 than my stock 4-spd/3:36 R180. Be advised that you will have to take the side buttons from inside your 3:36 and put them in the KR180 in order to use your current half-shafts. It's not hard and gives you the opportunity to put new seals in, You will also need to get a red speedo gear so your speedometer is accurate. Look on hybridz for a complete differential sticky thread that will tell you all you need to know about differentials and making the side button change.

Cheers, Mike

[gnosez]

Carl - actually a lot of us used the stock R180 and raced them on weekends and then drove the car to work on Monday. I completely agree that race teams and folks with more money had the diff modified but there were more of the OEM versions being run than the other way around IMHO.

Jon - completely agree that the gap between 2nd and 3rd in both the 4-spd and early 5-spd is too wide for an under-powered car. We swapped out the 4 spd in the race car as it was killing us as we went from 2nd to 3rd going uphill.

[ezzzzzzz]

I ran a R180 with a nismo LSD and 4.11:1 r&p with a Type-A 5 speed and then with a KA conversion 5 Speed in my 240Z. It was a pleasure to drive but required rapid shifting even in normal driving. The LSD finally had worn to a point of needing a rebuild. I opted to build a R200 with a Quaife LSD and 3.90:1 r&p. The car is much more enjoyable to drive and still pulls well with the lightly modified 2.4L. The best way I can describe this is I can actually get through an intersection from a stop without having to shift gears (assuming I wasn't running the rpm's up to 4000). If you're using the car primarily on the street then I'd lean heavily towards the 3.90:1 r&p. I'll qualify this by saying I don't autocross or race my cars anymore. The days of building fire-breathing-pain-in-the-arse-to-drive-constant-maintainance-breaking down cars are behind me. As someone who has owned over fifty cars and trucks (mostly performance intended) I now prefer good performance, reliability and longivity over 'anything goes'.

[jmortensen]

The difference between a 3.90 and 4.11 should be a couple hundred rpm in any given gear, and the 3.90 came stock in the ZX. I wonder if you didn't run a larger tire or something that helped to make a larger difference than the ratio alone would have done. I would think that the gear ratio change would by all means be noticeable, but not make one into a rapid fire shifting machine that had to be constantly changing gears while the other just loped along in one gear no matter what you did, if you get my meaning.

[jbuenviaje]

Do u guys know the 5spd gear ratio for 1985 200sx N/A

[jbuenviaje]

Datsun/Nissan Transmissions

MANUAL

Trans Type 1st 2nd 3rd 4th 5th other Reverse *Notes*

4sp RWD

F4W63L 3.382 2.013 1.312 1.000 -.--- -.--- 3.365 *710*

F4W71A 3.549 2.197 1.420 1.000 -.--- -.--- 3.364 *240Z*

F4W71B 3.382 2.077 1.308 1.000 -.--- -.--- 3.382 *240Z/810/Maxima/620*

F4W56A 3.757 2.169 1.404 1.000 -.--- -.--- 3.640 *B210/210*

F4W60L 3.513 2.170 1.378 1.000 -.--- -.--- 3.764 *210*

F4W63L 3.382 2.013 1.312 1.000 -.--- -.--- 3.365 *510*

F4W63L 3.657 2.177 1.419 1.000 -.--- -.--- 3.638 *510 Optional*

5sp RWD

FS5W60L 3.513 2.170 1.378 1.000 0.846 -.--- 3.464 *210/510*

FS5W63A 3.382 2.013 1.312 1.000 0.854 -.--- 3.570 *S110/610/510*

FS5W71B 3.321 2.077 1.308 1.000 0.833 -.--- 3.382 *S12*

FS5W71C 3.321 2.077 1.308 1.000 0.864 -.--- 3.636 *S12/280Z*

FS5W71C 3.321 1.902 1.308 1.000 0.759 -.--- 3.636 *Z31 N/A*

RS5R30A 3.214 1.925 1.302 1.000 0.752 -.--- 3.369 *Z32*

FS5R30A 3.324 2.077 1.360 1.000 0.711 -.--- 3.382 *88-89 Z31 Turbo*

FS5R30A 3.324 2.077 1.360 1.000 0.751 -.--- 3.382 *87 Z31 Turbo*

*89-86 Pathfinder 2WD with 6 Cyl*

*87-96 Pathfinder 4X4 with 6 Cyl*

*86-96 Pickup 2WD with 6 Cyl*

*86-96 Pickup 4X4 with 6 Cyl*

FS5R90A 3.350 2.056 1.376 1.000 0.752 -.--- 3.153 *84-86 Z31 Turbo*

So i guess perfect tranny combo for KR180 4:11 diff is FS5W71C tranny

FS5W71C 3.321 2.077 1.308 1.000 0.864 -.--- 3.636 *S12 (200SX)/280Z*

[jbuenviaje]

FS5W71C tranny from 1977-1980

[IdahoKidd]

His original post was for the street and highway. Somehow it got over to racing. I don't race, and I don't notice the big hole between 2nd and 3rd. Maybe the tranny I have isn't the tranny I think I have, but am still happy. In my world, highway is getting into 5th and staying there until I get there. That said, having read your posts for some time, I wouldn't even begin to challenge you. I am certain you have forgotten more about these cars than I'll ever know.

[adamr]

I have done the later 5spd and 3.90 in a '76 and my '70. The second to third gear shift is soo much nicer. The car is fine on the highway. This tranny and diff were designed to go together to move a ZX which gained a lot of weight over the years since it's birth as a 240z. It isn't radical, and is a great performance upgrade. Plan on new Ujoints and bushings while you are in there.

Adamr

[240ZX]

I have to agree with Pop's Z! In my 1970 w/N42, late model 280ZX 5spd, and R200 w/ 4:11 posi.....its a perfect combination for the twisties. When driving the freeway at 3000rpm however, I'm traveling at approx 70 to 73 mph. (my rear tire size is 235-40 x17....about 24" dia.) I had the 3:90 set-up before but with low HP the lower gearing certainly helps....my N42 is stock except for headers and upgraded ignition....maybe 150 HP at the flywheel. All in all, it comes down to personal preference.

Tom