General Chat
Q:
Are there any Z guys around here who still stick with their 4-speed tranny?
I have the chance to swap my 4-speed for a 5-speed, but I have never felt the need to go into another gear in my car, even on the freeway.
I realize the 5-speed is practical, cheap, blah blah blah....
I am thinking along the lines of..."if it ain't broke, don't fix it"
Are the 5-speeds, seeing as they were produced at a latter time, more complex? Are they any more efficient than my 4-speed? or is the extra gear just bolted in?
Spm
youth is wasted on the young
A:
I still run my 73 with a 4-speed and I like it. I have thought of "upgrading" to a 5-speed but have not had the opportunity. If you don't feel the need then don't do it. Also, realize that there are different versions of the 5-speed. I do not have personal experince with them but from what I have read in the archives in the tech forum the later 280zx 5-speeds are better and have better gearing. Once again, don't take my word for it. You may want to search through the archives. Can anybody confirm this?
-------Senkyoshi
1973 240Z 4spd Dual Webers
"I spend too much time raiding windmills"
A:
Lunch, the 5 spd IS the same with an extra gear if it's 79 and below. If it is an 81-83 then the gearing is better and 5th is very far out there, BUT it was paired with 3.90 gears. If you use this tranny (81-83), either find some 3.90, 4.11, 4.38 etc, or it will feel really doggy (with great top speed potential!)
RR
72 240
A:
ya......but I don't need top speed potential......
I would rarely take it to 80mph. I use this car for around town and ocassional freeway driving.
I basically would like to know if the 5-speeds (79, or later ones) are stronger/less prone to breaking/more technically complex.
youth is wasted on the young
A:
Early 4 speeds are geared lower since they had 3.36 rear ends.
If you want the best of both worlds get a late model 81-83 5 speed, but swap in a 75-79 4 or 5 speed Input shaft and front countershaft gear for a tranny with low gearing and .83 overdrive.
The 1980 tranny is actually the same as an 81-83 tranny but with the old 1979 tranny 5th gear bolted onto it.
Later,Norm
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
Post Edited (Sep 4, 9:20pm)
A:
Yeah the early 5-speed that came in the 280z is just the 4-speed with an extra 5th gear. Having the 5th gear will drop your rpms about 400rpm at freeway speeds. Not a whole lot but it might help with gas mileage a little. A lot also has to do with what differential you have. If you still have the 3.36's (assuming you have a 240z) then I would say the 5-speed isn't worth it, it may actually drop the rpms too low where you are outside of the power band which means you'll lose gas mileage. As mentioned the late 5-speed from the 280zx has different gears and a much taller 5th gear. Some like the zx tranny for it's 5th while others say that 1st and 2nd aren't good for acceleration. There is a lot to consider when doing tranny and/or diff swaps. What are you looking to get out of it? At some point I plan to do like norm did and mix the Z and ZX 5-speed so that you get the good 1st and 2nd of the Z and the taller 5th of the ZX. Someday.........
1977 280z: Intake, exhaust, high flow cat, header, euro damper, cam, MSD, adj. FPR, 3.7 lsd, F+R sway+strut bars, 2580lbs
1984 300zx: intake, exhuast, high flow cat, headers, JWT ECU, F+R sway bars, F strut bar
06 WRX TR
A:
Here is my Old writeup from 1998
Subject: SECRET TRANNY RATIOS REVEALED
Author: norm ()
Date: 12-10-1998 14:06
Okay, I'm sure that this isn't a total secret, but I'm willing to bet 95% have never heard this one.Here's the deal, you can put a 74 260 4 speed trans. input shaft and front countershaft gear on an 81-83 5 speed and get some killer low end acceleration .The stock ratios are as follows. 3.06 1.858 1.308 1.00 .745 MODIFIED Ratios 3.70 2.245 1.58 1.00 .90 You run hard out of the hole with this setup but you do have a less than perfect gap on the 3rd to 4th shift.However I think this is a killer setup for autocrossers where speed doesn't go over 75, that is when you have to shift if you are running a 3.9 and 195/60 14 tires(If you shift at 7100 rpm).I liked this for 1/8 mi. drags, but unfortunately I had to shift to 4th gear about 90 ft from finish line and I didn't like the possibility of a missed shift costing me a race.However this would be great combo for someone with less hp because they would cross finish line in 3rd gear.
Okay, the next setup is what I am currently running in my 240 .This setup works better for 1/4 mile drags because the 3rd to 4th gear gap is better.Take an input shaft and front countershaft gear from a 75-79 5 speed and put it on the 81-83 5 speed and you get this setup. 3.42 2.07 1.46 1.00 .8326
Either of these setups really improves the drivability of any Z car and would really help accelerate a heavy 280 zx off the line without having to resort to a high rpm clutch drop to spin the tires up to the engines powerband. The last combo is this one. .Take the 81-83 input shaft and cs gear and put them on a 79 5 speed and you get this setup 2.98 1.85 1.17 1.00 .77 I guess this would work well with a4.11 to 4.44 rear diff and would give an ultra close shift from 3rd to 4th.I have not tried this combo yet. If you drag race and don't run slicks or street legal drag tires you will not reap the full benefits with the first two optional tranny combos.Good 60 ft times are essential to quick e.t.s and the first setup works terrific with sticky tires.I managed a 1.84 sec 60 ft with Nitto street drag slicks.This was done with an open 3.9 diff and the nittos spun hard off the line.With real good slicks and limited slip rear I am positive low 1.70 sec 60 ft times are possible. If anyone out there knew about this let me know. Because it took me 9 yrs of zzzing before it dawned on me!!!!
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
Post Edited (Sep 4, 9:21pm)
A:
I've got all the same info on a chart I made in the 90's with final drive ratios using all the different rear ends. Nothing really gives you a good sense of what it all means without actually trying it in the car, until that is, I used the cool transmission calculator and saw the gearing mapped out and it opened my eyes to the sx swap. No more 3-4 power loss.
I've always loved what the input shaft swap does for 2-3 over the early trannys, but recently at the drags, found the 3-4 shift a bit of a tall order.
Not so with the SX tranny. OR...if you use the 81-83 stock and use a 4.62 rear end, much better results for an even spread.
I actually tried the late input in early tranny (2.98) and found that, unless you were accelerating, shifting to 4th was like shifting back into the same gear.
Bottom line, there's a TON you can do with a Z and it's gearing. All of us like different set ups, and there's bound to be one for you. The later trannys are better and newer...
RR
72 240
A:
Lunch, if you DO like acceleration, but aren't overly concerned about the freeway driving, definetely do the input shaft/countershaft swap - you'll be blown away by the different feel, still have the same 1:1 4th gear with the added 5th.
RR
72 240
A:
Norm whats a good set up for a road course. I was thinking 3.06, 2.07, 1.46, 1.00, .77 with a 3.36 rear. First low to get off the line...but on a road course you generaly don't use first too often & a tall fifth for those long straights.
This whole world smells bad, I'd buy another if I had
back what I paid for another mother@#$%@# in a motorcade
A:
Yeah you are right about the 3-4 drop. I mainly run 1/8 mile around here so it wirked perfectly for me but when I went to the 1/4 mile track I could tell that 3-4 certainly wasn't optimal. Your idea of a 4.62 or even a 4.44 with an 81-83 tranny would be just about perfect.
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
A:
Hey John unless you are making major mid range torque and HP, gearing a .77 with a 3.36 will actually reduce your overall top end as your motor wont be able to pull into the powerband.
One reason I swapped my shafts was because even though I was running 12's in the 1/4 mile I couldn't break an indicated 125 mph in 5th gear. After the input swap I could hit an indicated 145 mph.
I would think a .77 with a 4.44 rear gear would be best, but others like TonyD and John Coffey would know beter than myself.
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
Post Edited (Sep 5, 7:17am)
A:
That's just what I needed to know. Thanks everyone.
I am still interested in the sx swap, you use the tranny out of a 200sx?
youth is wasted on the young
A:
Hey John unless you are making major mid range torque and HP, gearing a .77 with a 3.36 will actually reduce your overall top end as your motor wont be able to pull into the powerband.
So what are we talking 200 - 300 hp or over 300 hp to pull this gearing. I'm just short of a stroker with the mods to my engine.
This whole world smells bad, I'd buy another if I had
back what I paid for another mother@#$%@# in a motorcade
A:
If your car is an NA then I think that combo will never allow you to pull up to speed.If it's Turbo then that's a different animal. I had a .77 overdrive and a 3.9 rear and with approx 230-240 HP at the flywheel I couldn't pull past 125 mph indicated until I went with the .83 overdrive then I pulled up to an indicated 145 mph.
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
A:
I have a 78 that is mostly stock, and I still run the stock 4 speed/3.54 gears for now (don't fix what ain't broke) but I have a 82 ZX 5 speed sitting in the garage waiting on $$$ to buy a fidenza lightweight flywheel, and a performance clutch to compliment, and scavenge any HP that I already have.
I currently run 3000 rpm at 60mph, but am looking forward to the .745 5th gear getting the RPM down in the 2300-2400 range for mileage, and noise purposes. It would be nice to change the input shaft and have some steeper 1st and 2nd gear accelerations, I think that will now be part of the "new" drivetrain I install when all my ducks are in a row.
A:
_____________________________________________
'05 350Z Chrome Silver Touring
'73 240Z
A:
Ya know John, if you are runnning the 3.36 rear end you ought to be able to hit close to 140 mph anyway in 4th gear at 7000 rpm. I doubt if you would even get that fast on a roadcourse anyway,would you??
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12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998
A:
i got one of them boys sitting in my garage
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
As I said, thanks guys.
If you need to help me, you need to know 2 things....
1. N/A
2.120hp on a good day
oh, and 4 cylinders.
Everything everyone has said still applies though.
youth is wasted on the young
A:
The poor racer's close ratio 5 speed is the later NA 280ZX transmission with a Nissan .86 overdirve 5th gear set part number: 32310-58S54. No need to change input shafts or any of that other stuff. The swap will give you 3.062, 1.858, 1.308, 1.000, and .864. The gearing with 225/50-15 tires and 7,200 redline will give you the following:
With a 4:38 gear 5,000 rpm is 62 mph in 3rd, 81 in 4th, and 91 in 5th. Top speed is 135 mph.
With a 4.11 gear 5,000 rpm is 66 mph in 3rd, 86 in 4th, and 100 in 5th. Top speed is 144 mph.
The SCCA EP racers run the exact gearing above (unless they have a Nissan Comp tranny) but remove first gear so they don't pay a weight penalty for a 5 speed.
- John
A:
That's the 1980 Tranny. 81-81 have the .74 5th - never gonna hit any 5th in the 1/4.
Hey john, my SCCA racing friend is teaching at PIR this month and I'm gonna go take the class.
He drove my car and said it should be a lot of fun out there.
We're prepping his enduro car for an upcoming event and I get to help out.
I'm the guy you gave a hard time about racing the GT Mustang - went to the drags after that and got a 14.065. Gonna stick to the race track from now on...
RR
72 240
A:
> I'm the guy you gave a hard time about
> racing the GT Mustang - went to the drags
> after that and got a 14.065. Gonna
> stick to the race track from now on...
I did? Must have been a bad day for me. Congrats on the 14s.
- John
A:
"If you use this tranny (81-83), either find some 3.90, 4.11, 4.38 etc, or it will feel really doggy (with great top speed potential!)"
The top speed potential is a moot point. Unless you have a SERIOUS turbo setup, a stock open-mawed S30Z will have absolutely no difference in top end potential with any of those gearsets mentioned.
Matter of fact, in a STOCK vehicle, they will all go EXACTLY the same speed top-ended, it's just one will get there FASTER.
While thinking you have a 162mph speed "potential" at 6500rpm using a 3.36 and a late ZX tranny, in a N/A Z-Car (ESPECAILLY AN S30) it's a pipe dream.
300HP? Try more like 450+ to get much over 150mph out of a Stock Bodied S30.
I have had an open gentlemans bet for a certified speed above 150 in a N/A 6 Cylinder Non-G-Nosed S30. Nobody has done it yet. Closest was john Coffee, but he quit on me and sold his Rusty Old Datsun! he was reeeeal close, and might have made it, but we will never know...
You got a stock Z, you will go 125mph. The only difference will be the speed of the engine when you achieve it. In my 260Z with a 3.70 and late ZX Tranny it's at 4750rpms. In my 75 Fairlady Z 2/2 with a 3.9 and early Z Five Speed it's at 5300rpm....towing a trailer or not!
Stock will only go so fast, and for every ratio you add above the 3.90, given the early lower geared tranny, you will add about 500 rpm to top speed rpms needed. From this you will see that for an L28 the early tranny and a 3.9 is almost ideal with the HP peak of the stock engine occurring very close to the top speed of the vehicle (damn if those Nissan Engineers didn't know something about their craft!)
Extrapolating, 3.90 and 5300, 4.11 and 5800, 4.38 and 6300, 4.62 and 6800.... so technically the 4.62 might be over-revved for an L28, but NOT for an L24! So yeah, pick just about any ratio you want, it's not going to affect your top speed one whit, but it WILL increase your fun-to-drive quotient quite a bit!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
Yeah, but if your gearing is too high for the motor to pull into your power band then your top speed will be lower as evidenced by the example of a Corvette going slower in 6th gear than in 5th gear.
-----------------------------------------
12.804 @ 107.26 mph on crappy street tires with Dual SU Powered 2.9L Stroker!
ZCAR.COM member since Aug 1998