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Gearbox options for 250whp 280zx (s130)


bigbreak_2000

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My car is 81 280zx 2+2 and has the stock datsun 5 speed g/box. I have a 3.2l stroker (non turbo)in it, that currently puts out over 218 Mustang dyno whp with the P79 head, n47 FI intake and mild cam. We're putting a p90 head, ITBs and bigger cam, so the goal is about 240-250 whp. I read many places that Nissan went with the T5 in later model S130s because the standard close ratio 5 speed can't handle more that 180-200 hp. Mine's been holding out well over the last 3 years since I had the 3.2 in it. It also has the stock r200 3.9 with stock U joint on rear axles. The only other upgrade I have is a light flywheel. No problems so far. No weird noises or vibrations. I also use redline oil in the gearbox. Along with the engine intake changes I am putting in a LSD. I do not drag race or autocross. Should I really be concerned that the gearbox will have a much faster rate of wear and eventually destruct because of the amount of torque applied through the drivetrain? I could buy a cheap T5, recondition it, but then I'd also have to do modifications to the driveshaft and mounts.

 

I want to hear what your real world experience has been with the stock 5 speed mated to a much stronger motor. Has it hold up well under racing conditions, when had you seen it actually failing, etc.

 

I really like the ratios on the stock 5 speed. 1st is low , but 2nd-5th is an excellent match for the torque strong 3.2l. If anything I wish 2nd was higher geared, to get to 60 you have to switch 2-3rd and that is a rather long action. A short shifter would have been nice but cant have that on the stock 5sp. So I want to stay with the stock 5sp if the risk of it breaking is not that large. If I do have to go to a stronger g/box might as well consider a WC T5 or some other g/box.

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I have a 5 speed nissan box of some sort, not really sure which one it is, but it's been living with 180-200rwhp for 2 years since I got it, and 270rwhp for most of this year. I might have 2000 miles on it with the higher power(2 trips to the strip on street tires, 4 autocross events, and quite a bit of street abuse), but so far so good.

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Your tranny should be fine, I believe TimZ posed that his tranny just gave up around 350hp/tq.

 

If you want a little bit stouter tranny, you can always do the 240sx tranny swap. It has identical gear ratios, can be had for practically nothing if you're looking around, and you can put a short throw shifter kit in it. You'd need your driveshaft shortened by 2" give or take, and will need to machine the L28 tranny bell housing.

 

http://atlanticz.ca/zclub/techtips/240sxtransmissioninstall/index.html

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Does the Redline oil work well in the stock 5 sp?

 

I have a 1983 5 speed in my 240 that I rebuilt myself. Only complaint is I can't really make "lightning" fast shifts. No grinding, but I guess the syncros just take a split second to do their thing.

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Does the Redline oil work well in the stock 5 sp?

 

I have a 1983 5 speed in my 240 that I rebuilt myself. Only complaint is I can't really make "lightning" fast shifts. No grinding, but I guess the syncros just take a split second to do their thing.

Redline made a great difference. Although my gearbox only has 20,000 original miles on (I bought the car from a guy who stored it for 30 years), the shifts are smooth and it definitely is more quiet than what it used to be. I really can't complain, I think it was money well spent.

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I'm using GM synchromesh, according to some datalogs, the time between getting off the gas and getting back on is .100-.150s. The front bearing in the tranny does seem to make a little noise though.

Edited by letitsnow
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Your tranny should be fine, I believe TimZ posed that his tranny just gave up around 350hp/tq.

 

If you want a little bit stouter tranny, you can always do the 240sx tranny swap. It has identical gear ratios, can be had for practically nothing if you're looking around, and you can put a short throw shifter kit in it. You'd need your driveshaft shortened by 2" give or take, and will need to machine the L28 tranny bell housing.

 

http://atlanticz.ca/zclub/techtips/240sxtransmissioninstall/index.html

 

As John mentioned, it depends on how you treat it, but mine didn't give up until I was in the neighborhood of 450rwhp/470 lb-ft, at which point ALL of the teeth decided to leave third gear on an upshift at WOT :blink:

thirdgear1.jpg

 

As I recall Mr Thagard was in the car with me at the time (he's bad luck :P) )

 

I was using MT-90 too, BTW.

 

Assuming that you don't drive it like a complete idiot, a well-sorted stock Z trans should live quite some time with 250rwhp.

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You could always get the z32 trans adapter from autin hoke or mazworx and go that route. I just picked up a tranny for 50 bucks and austins kit cost 400 plus the price of a driveshaft ( im thinkin 1-250),that coupled with an r200 and cv axles would give you a STOUT drivetrain. I heard rumors of the z32 trans taking 600 ponies all day, so with my white bunny special, I should be good to about 350-400.

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My experience is that the T5 is weaker than the early Nissan 5-speeds, though my experience is from different vehicles, one being much heavier, but making a little less power.

 

I'm still intrigued that people that own early Datsuns and Nissans want to go to the T5, while people that own cars that came with them of other makes want to get rid of them...

 

I'm planning on a Z32 trans behind my next engine.

 

Currently getting closer to 300 HP (if not eclipsed it), calculated to be around 250ish WHP (from trap speed, last year, making less power than today) so far, with a 1981 N/A 280ZX trans, with the only change being from the stock aluminum shift forks to earlier 4 speed cast iron shift forks. I only did that because my 1-2 shift fork had been broken for a few years, and once I lost the ability to shift into 1st and 2nd, I decided it was time to fix it. lol I only had a 4 speed available to me at the time, so I went with those parts.

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I guess the main takeaway for the OP was that for 240-250 rwhp there is no reason to go to the trouble and expense of swapping transmissions, assuming the current stock trans is in good repair (and if it isn't just get it rebuilt).

Edited by TimZ
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