Close ratio Z box

[zr240]

I am trying to get a close ratio gearbox for my race car. I am in Australia so if anyone in Aus has one or knows were to get one please contact me. Also If anyone out there in Z land can give me info on the close ratio boxes please do

THanks

Ash

[hmsports]

Ash,

Check out Quaife. They may be a good place to start.

Also, Taylor Race Engineering is a specialist in many types of gearboxes.

Hewland is another brand to look at.

Best of luck,

Rick

[HS30-H]

Hi Ash,

The following information on Nissan's early 1970's "Option" sports / race transmissions might be of interest to you:

*32010-N3130 "Close Ratio Overdrive"

*32010-N3030 "Wide Ratio Overdrive"

*32010-N3220 "Option 1 Race Transmission"

*32010-N3221 "Option 2 Race Transmission"

*32010-N3222 "Option 3 Race Transmission"

*32010-N3201 " Rally Transmission"

All the above were based on the FS5C71B / F5C71B "Bent Stick" boxes, and the Options 1,2,3 & Rally type all had "Direct Fifth" 1:1 top gears ( sometimes called the "Direct Top" or "Dogleg" boxes ). These are great for the racer, as you don't spend time going in and out of fifth gear on its dogleg with the danger of wrong-slotting reverse. Once you are out of first gear you have a conventional H pattern gate for second to fifth gears, which is quite handy on the track. The lack of overdrive is not a problem on a proper race car, and can be adjusted-for with a judicious rear-end ratio choice.

Most of the Option 1,2 & 3 transmissions ended up in the USA, and are now very hard to find in good used condition ( don't bother trying to find a new one ). These Direct Fifth boxes have quite a few differences internally to the "stock" B type boxes, and the selector forks and rails are now all but unobtainable.

I can give you a list of the ratios in all the above boxes, which are quite interesting - but a bit longwinded to post up here. Let me know if you need it.

QUAIFE will be a bit of a waste of time for you to call I'm afraid; they used to stock a super-wide straight-cut gear set for the B boxes ( they listed it as a 240RS part ) but they have not made these for a few years now. They don't seem to be very interested in making any more either. You can't bolt in the 240RS box complete as it had a different bellhousing that would leave the trans. about 40 degrees from vertical if you bolted it to an L6.

Looking at your car, it seems to me that you might be pretty much unhampered by rules and regs. - in which case you might like to investigate some of the boxes from 2WD Skylines that can be made to fit with a bit of engineering nous.

Good luck,

Alan T.

[zr240]

Thanks for the info guys.

Alan I would love to know what the ratios were in the option boxes. If you could email them to me at www.zr240@hotmail.com I would greatly appreciate it. There is a guy here who can make me a custom close ratio box (what ever ratios I want) for around $2500 aussie dollars which sound ok just need to start saving. I am allowed to fit a skyline or silvia box for the class I run but havent been able to find any close ratio boxes in Australia and it costs too much to import. The main reason I chose a z for racing is they are without dought the best value for money sportscar to race around.

Thanks again

Ashley

[HS30-H]

Hi Ashley,

I'll write out the ratios and e-mail them you direct.

That custom-built box with " any ratios you want" sounds a bit too good to be true. Where will he be getting the gears from?! There's a fair bit of mix-and-matching that you can do to come up with something close to a close-ratio overdrive box, but its not unlimited and I think he may be exaggerating somewhat.........

Of course, if he really CAN come up with something like the Option direct-top ratios then it will be good.

Do remember that the best choice for a circuit car is NOT going to be anything with an overdriven fifth gear, and is going to have that dogleg first pattern that will allow you to use second to fifth gears in a conventional "H" gate ( must faster and less easy to fumble a shift in ). Trouble is, this would demand the different rails and selectors of the dogleg box - which are all but unobtainable................

Alan T.

[zr240]

hi alan

thanks for emailing me the ratios. The guy will get the gears cut for that price. he makes 5th 1st then the 2nd 3rd 4th and 5th become the H pattern with the 1 to 1 5th if you know what I mean.

[biker]

Hey Allan T,

Any chance of puting up the close ratio box gearing for the options that you mentioned and sent to Ashley.

Am undertaking racing a Zed in Oz as well and need to get more acceleraton out of the corners as well as down the straight. Can't give Ashley an advantage!!

Alternatively, you could email to biker@powerup.com.au

Thanks

[HS30-H]

Hi Biker,

I'll send it to your e-mail address, as it is too long ( wide ) to fit on these pages without messing about ( and I'm not computer literate enough to sort it out ).

It's not "secret" information; its data that Nissan had available and has been reproduced in a lot of the tuning books and Sports Option parts lists. Anyway, I'll mail it to you.

Ash,

That deal sounds good to me. A proper race-version of the "B" box with the dogleg shift pattern and direct fifth ( non overdrive ) is a LOT of work to put together. Cutting gears is also not cheap, and there will be a lot of fabrication involved in making the shift forks and rails. If you firm up the spec. with this supplier and you are sure that he can do the job successfully - then I would be interested in a couple of boxes myself. Let me know how it proceeds. This might be a way for you to finance your own project.

Regards,

Alan T.