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duragg

tranny gears wanted (Discussion ratios / gear swaps)

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Looking for an early 5th gear and accompanying counter-gear to adapt to my 1983 5 speed for track use.
Like to end up with a much shorter 5th.

 

So for the historical record, this started as a WTB post with me looking for a particular 5th gear and Countergear.

Morphed into a discussion of various years of trannies.

Edited by duragg

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Looking for an early 5th gear and accompanying counter-gear to adapt to my 1983 5 speed for track use.

Like to end up with a much shorter 5th.

I have a complete 5/spd broken down, but i'll have to figure those parts out among the lot. Note* these parts were stored properly and not outside in the weather.

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Thx.

Recall the 1983 i have now has the highway friendly .745 overdrive.

The 77-79 has the .864 ratio which I now want for track use.

 

I need to review the gear teeth counts to see if this will even work.

I have a 1982 5 speed in pieces which I use for test work.

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I made a little spreadsheet with all the varios Main and C/G ratios and the 5th gear ratios.

It looks like there are 2 Main / Counter ratio styles and 2 5th gear styles.

 

Even if I swapped the older 5th gear it only takes my .745 to a .773.

Only way for me to get to an .864 is to use the earlier style main and counter gear which loses the close-ratio-ness.

 

So may not be a way to do this.

If you email me I can send the spreadsheet.

 

TJ

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I tried to find some old threads over on zcar.com by Norm the 12 second SU guy but it's pretty impossible to find anything over there.  Their search engine is Google.  But I did find an old John Coffey post that might be interesting -

 

http://www.zcar.com/forum/13-car-talk-forum/244617-4-vs-5-speed-3.html

 

 

Pretty sure that the 12 second guy had some threads on swapping 5th gear.  Might be worth more looking.

 

 

Edit - actually the information I was looking for is on Page 1 of that thread.  John Coffey's post is on Page 3.

 

Edit 2 - http://www.courtesyparts.com/overdrive-p-343102.html

 

Edit 3 - of course there's always someone raising a question - http://sports.dir.groups.yahoo.com/group/westcoastzracer/message/8440

Edited by NewZed

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For a 0.86 5th, you need to find a gear pair that works out to .86 * .7931 > 0.682.  Like 30 and 44.  Or 21 and 31 (close). 

 

The last edit in my post #7 really just raises the question of what the tooth count is on Nissan part #32310-58S54.  The guy says it's 22 and 37 but who knows.

 

Maybe you can find someone out there to open some boxes for you.

Edited by NewZed

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22 and 37 doesn't do it either.

See below.

 

post-1894-0-60357100-1368220052_thumb.jpg

 

I guess the question becomes what sort of 5th gear teeth are available.

 

We know early:  19/31 with .7097 main ratio = .863ish

We know late:  26/44 with .7931 main ratio = .745ish

 

Probably needs to be moved to a Drivetrain section and not the For Sale.

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From Norm (the legendary 12 second SU dude):

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
tiresicon1.png(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
enginesicon1.png 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!!!!

Edited by duragg

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I hope I did this right,,, going by above data I tried to capture each configuration.

 

1)  Stock 1983 5 speed  (for racing the 4-5 is a little long)

post-1894-0-24206200-1368376156_thumb.jpg

 

2)  1983 5 speed with 1977 Overdrive gears (not bad actually..)

post-1894-0-87659200-1368376155_thumb.jpg

 

3)  Norms 1st configuration above

post-1894-0-89863400-1368376156_thumb.jpg

 

4)  Norms 2nd configuration above

post-1894-0-55977900-1368376156_thumb.jpg

 

5)  Norms 3rd configuration above

post-1894-0-21187500-1368376157_thumb.jpg

 

COULD A MODERATOR PLEASE MOVE To THE DRIVETRAIN SECTION Pleeze?

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#2 is the gear set that 1980 ZX 5 speed uses.  For some reason Nissan only kept it around for one model year.

 

I have one and 5th gear does feel like it belongs there, not a big jump to 5th.  I had an 83 in my car for a little while and the 4-5 jump was noticeable.

post-8864-0-38448000-1368378020_thumb.jpg

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Yes.  Good eye.  I see that now.

So a 1977-1980 5th gear would help that 4-5 reach a little for non-highway use.  Thanks for pointing that out.

 

I like the 1983 for the reverse-threaded main shaft nut.  I have a 1981 / 1982 5 speed in pieces which has same ratios but not the reverse nut.

 

My apology to the Moderators for "reporting" this post instead of just asking it to be moved. 

But thanks either way for moving it.

Tj

Edited by duragg

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Finally got myself a 1980 vintage 5 speed.  Just to junk it for 2 gears haha.

 

Should be able to make my 2 parts trannies into one good one as a spare.

 

 

FAIL.

It has 26/44 teeth.

Still looking for an earlier 19/31 gear set

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I'm not even certain that swapping an early 5th into a later box would work.

According to the FSM the synchro is a totally different style.  Might require swapping a bunch of parts which may or may not be compatible.

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Posted (edited)

OK, I know I am resurecting an old thread here but I am trying to learn. I am currently running a 510 with a stock 4 speed in vintage racing and sorely need to upgrade the trans.  I scored what appears to be a very nice 82 NA five speed. I also picked up an NOS still in the box 32310-58S54 OD gearset. It is definitely 22 x 37.

 

I also got these spreadsheets from another source labelled "83 modified and tested" and "Norm 12 sec mod".

 

                             Main C/G Ratio     22 31    0.709677419  

                                                1         33 14   3.321429    

                                                 2        27 20   1.902273    

                                                3         26 28   1.308442    

                                                4         1 1       1  

                                                5         22 37   0.837838         

 

The ratios do not match Duraggs for the "83 modified testable" nor the "Norm 12 sec Mod" ..... but the 22/37 set yields a tasty .837 OD!!  So now the question is (I guess) does anyone recognize the ratios in this table and what gearsets from where would yield them??

 

I am beginning to think I should just slap the 82 five into the 510 and take whatever improvement I get - very confused at this point.   Great info in these threads by the way, Thanks 

 

(The spreadsheets got scrambled going over into the post so I had to just put the info in this table)

Edited by gereed75

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