Which is better for performance and any disadvantages going from 4 to 5 spd? This question is for a stock 240z

well I prefer the 4 speed myself when i was road racing. Could stay in a gear longer not having to shift as much. But I liked the 5 speed better for drag racing. It just depends also on your read end gearing. But on my stock 240z i had I prefered the 4 speed. Just seemed to perform better.

I have the 4 speed and 4.11? gears, and for autoX I think It'll be great, but I'd love to have that fifth gear so I don't redline when I hit the speed limit on the highway....

bw

I believe most 4 & 5 speeds have the same gear ratio 1-4 & reverse. You could find a 4sp with different ratios it would just require a little homework to find the correct year. If you plan on keeping your Z stock and use it for street driving a 5th gear is always nice when your on the highway. I don't think there are any disadvantages.

For a street car, I like the 280zx/810-910 Maxima 5spd. It has a higher 5th gear for highway crusing than the 280z 5spd. 1st, 2nd, and 3rd are slightly lower in the 4 spd than in any of the 5spds.

Probably not much help but FWIW,

I like the first 2 gears of my '73 4 speed with the R190 4.44 rear end for autox. I don't like the 2nd to 3rd spread though and the car never sees 4th anymore. The 5 speed may have a closer 2-3 spread but it probably moves the wider spread down to the lower gears IIRC.

When it had a 4.1 rear end on the street it scooted up well over 100 MPH very easily and I thought the 4 speed gears were just about perfect since I don't drive much faster than that ever. But the higher crusing revs and associated higher noise levels made it more tiring to drive. Gas mileage has never been a concern with me for "fun" cars.

With the stock rear end, it was just about a perfect cruiser at the expense of a little more spirit from the 4.1 gears, so I really wonder why so many people put 5 speeds in the 240's (unless they put the shorter gears in too).

I had the BW T5 in my '83 280ZX turbo and I really don't remember feeling one way or the other about the gears. They were probably just right for a turbo cruiser. I got lots of speeding tickets on the Interstate in that car too as it likes to cruise in 5th at much higher speeds than the 240Z. I do vivdly remember the thing had plenty of problems with the input shaft, presumabily due to the extreme heat from the turbo and that it is very heavy to lift when trying to put it back in after an R&R.

Early 4-speeds like mentioned earlier.. have the same

1-4 gears and Reverse as the

Early 5-speed transmission.

However, the later 5-speed transmissions in the ZX's have a wider gear box in all gears from 1-5 and reverse....

In my opinion with the stock rear end in a 240Z... the Late 5-speed is good.. and the early... just has quicker shifting (MPH wise)

Aren't the later ZX 5 speeds considered the close ratio units and the early 280Z 5 speeds the wider ratio units? If I remember correctly, the ZX trannies have a little higher 1st gear but the spacing between gears is less than the early 5 speeds.

Anyway, for a street car I would recommend the late model ZX tranny with a 3.90 or 4.10 rear end.

Go here for some tranny ratio data: http://www.geocities.com/z_design_studio/

COOL, huh?

I put an 84 truck tranny (gearset, anyway) in my 240Z mit 3.1 liter monster motor. It has somewhat close 1-4 spacing, like the later ZX boxes, and also has the close 4-5 like the earlier 280Z/early ZX 5-speed. Best of both worlds!

I like the later 280ZX 5-speed, but it was killing me at Watkins Glen's long back straight (too tall 5th gear). So I got the truck 'box.

IMO, any Z 5-speed is better than the 4-speed.

Originally posted by PrOxLaMuS©

Early 4-speeds like mentioned earlier.. have the same

1-4 gears and Reverse as the

Early 5-speed transmission.

How did you arrive at that? Everything I have ever read seems to say that the ratios differ 1-4 between the early 4 spd and any 5 spd.

What about a daily driver? The early '74 260 is my daily driver. I do a lot of freeway driving, about 80 miles round trip once or twice a week. The rest is standard surface stop-and-go. I'd like to make her faster, but I have to watch the mileage at least somewhat. Would a 5 speed be beneficial for what is purely a street car that may someday have some performance mods?

A 5 speed won't make the car faster per se but it will help with highway fuel mileage.