5 speed in a 4 speed question

[Marty Rogan]

The 78 280Zs came with a R200 if they were a manual trans and a R180 if they were an automatic.

Thanks. I am pretty sure mine came out of a '78 automatic.

Marty

[ktm]

If I went with a 5-speed, I would definitely drop in a 3.90 if not a 4.11 like your are planning. I have a spare 3.54 sitting in my garage (my old one that was whining). If I run across an LSD unit I may make a 3.54 LSD as I plan on keeping my 260z 4-speed.

[Carl Beck]

Carl,

I certainly respect your opinions but, the 3.90 gearing was the stock set-up for the ZX 5spd (N/A cars) and no by means drag race gears. Many have done this swap without changing the diff gears and most all have complained of too high of gearing....eventually they wind up going with the 3.90.

Tom

Hi Tom:

Yes it was the stock set up for the 280ZX - and the 280ZX was heavily bogged down with emissions controls and putting out 135 BHP (132 for California), plus being about 600lbs heavier than a 240-Z (2350lbs vs 2970lbs). So in that set-up - less power and more weight - the 3.9 was needed {the 79 ZX was only 2900lbs.. so 3.7).

15.7 pounds per HP for a stock 240 vs 22 lbs per HP for a stock 280ZX. The ZX simply had to be geared lower for stop and go - and having the 5th gear added to make the reported MPG acceptable..

True also that many people that make the swap - do so because they are more motivated by acceleration performance improvements - than I am - I clearly stated that my goal was better over-all driveability. My main point was that in my opinion the stock 3.36 is just fine for my intended use. I do believe that everyone has to really think about their intended use..

BTW - if you use the 77/79 5spd. the transmission gearing is all but the same as the 4 spd.. only with the additional overdrive 5th.

FWIW,

Carl B.

[Arne]

I agree with Carl. It totally depends on how you use the car. While I actually wouldn't mind having a tall fifth gear for cruising, I certainly don't need quicker acceleration around town. If I were to put in a five speed, I'd stay with the 3.36 also. (It's not likely that I'll go that way though, I don't want to have to cut the tunnel of the red car, which came with a Type A four speed.)

[Carl Beck]

Hi Arne:

Just a point of interest - at the ZFest in Florida last fall - we looked at a Series I car with a type B five speed. The owner used the shifter from I believe he said a 200SX. No cutting of the tunnel was necessary as that shifter had the correct "S" shaped bend from the factory. he was using the stock rubber boot and vinyl shift lever cover as well. So I guess there is a way to do it...

FWIW,

Carl B.

[e_racer1999]

i'm with carl on this one. the 3.36 is fine in my car. although i do want a bit lower gearing and DO plan on going with the 3.9 R200, my set up is great the way it is. the only reason i am swapping to the r200 is because i plan on doing autoX. although i think my ideal would be somewhere around 3.7

[Arne]

Hi Arne:

Just a point of interest - at the ZFest in Florida last fall - we looked at a Series I car with a type B five speed. The owner used the shifter from I believe he said a 200SX. No cutting of the tunnel was necessary as that shifter had the correct "S" shaped bend from the factory. he was using the stock rubber boot and vinyl shift lever cover as well. So I guess there is a way to do it...

FWIW,

Carl B.

I had heard that there was a lever that worked, so that's good to know for the future. If I ever have a problem with my Type A, I may want to put a 5 speed in and store the 4 speed for a while.

i'm with carl on this one. the 3.36 is fine in my car. although i do want a bit lower gearing and DO plan on going with the 3.9 R200, my set up is great the way it is. the only reason i am swapping to the r200 is because i plan on doing autoX. although i think my ideal would be somewhere around 3.7

That's probably the right way to go. The 240Zs that came with the Type A 5 speed (outside North America) came with the 3.7. Probably a nice compromise, although a bit hard to find these days?

[ktm]

You can get near the equivalent of a 3.70 by using a 3.54 differential and a 260z 4-speed. However, it does require swapping out by the transmission and differential to attain this goal. As I stated earlier in the thread, I have this set-up and love it.

[geezer]

Hi Arne:

Just a point of interest - at the ZFest in Florida last fall - we looked at a Series I car with a type B five speed. The owner used the shifter from I believe he said a 200SX. No cutting of the tunnel was necessary as that shifter had the correct "S" shaped bend from the factory. he was using the stock rubber boot and vinyl shift lever cover as well. So I guess there is a way to do it...

FWIW,

Carl B.

I am using a type B 5 speed with a S-shaped shifter in a series 1. It takes the regular boot, but the forward part of the opening needs to be trimmed slightly. My shifter is modified, not stock.

[jmortensen]

You can figure out what diff fits your purposes best with a calculator like this one: http://www.geocities.com/z_design_studio/

Your average NA L engine isn't going to have the gonads to push a Z up a hill in 5th gear with 3.36's in my experience. A friend of mine has a 70 with an L28 and ZX 5 speed and had a 3.90 diff with SUs, then broke her LSD and swapped in a 3.36 and was very upset about it. She wouldn't use 5th unless the road was FLAT, and the car was a slug off the line. She's not a racer, just likes to accelerate onto the freeway and in general likes to drive a fast car.

FWIW, the difference between the 3.36 and the 3.90 is about 500 rpm at 70 mph, so the rpm jump is not huge. However, the torque multiplication is 16% greater with the 3.90. That IS huge, and will make a VERY LARGE difference to the driver.

[HS30-H]

The 240Zs that came with the Type A 5 speed (outside North America) came with the 3.7. Probably a nice compromise, although a bit hard to find these days?

No. They came with the 3.90 diff ratio.

Anybody who wants a 3.36 gear in an S30-series Z with less than 200 WHP probably should have bought a four door sedan instead. :classic:

[Arne]

The 240Zs that came with the Type A 5 speed (outside North America) came with the 3.7.

No. They came with the 3.90 diff ratio.

If you say so, as you're there and I'm not. But my factory service manual for '70-71 S30s shows a 3.70:1 with the Type A 5 speed, as does this clipping from the original Road & Track Tech Analysis for the 240Z. R&T might be wrong, but I'd generally expect the FSM to be moderately accurate.