Gearbox Mods For Racing

[Noddy]

Perhaps it is just that Im a ham fisted monkey, but, I have been having trouble with the 3/4 cluster in my R33 gtst box. I find that the 3 tin clips that hold the selector dog fold the ends off if they get rushed. Then soon after they fall out and the dog doesnt mesh onto the syncro or gear making the shift clunky/grindy as all get out. Most other boxes have a solid blocker system, like the setup in the 1-2 cluster and is much more robust.

Initially the tripple plate clutch was swapped out for a good single to reduce drag on the input shaft, which helped, but now that I'm giving the GT3's a hurry up at Morgan Park, I am pushing through the gears and tending to stress these clips and having to replace them every meeting.

How do you guys fair with the clips?

What did the old group A 32's do? They have the same gear set, we have actually have a 32 gtr gear set in at the moment. It was a cheeper option for a spare set on rotation.

[sweefu]

Also interested in this
Have heard of this happening to people with Z32 as well, same gearset.

[Noddy]

Z32 is the same. There were some up dates in late R34 boxes but, esentially the same.

[Roy]

Dont use short shifter for starters? Are you using one?

[Noddy]

The shifter has an extension to the knob. Its about 50mm longer/ taller than a std knob position, slow shift kit of sorts.

[Noddy]

We have added an extra guide to the 3/4 selector fork, the thought is that the selector dog isn't supported propperly and can fall over. The extra guide might help maintain it in an upright position and take some of the load off the 3 clips. We will get this set back toghther and test it out at Lakeside this weekend.

Edited March 10, 2014 by Noddy

[chez00]

That's a good idea, interested in how this develops - the SR20 box has the same issue too. I'll have a look when I'm in the workshop tomorrow but perhaps there's a way of going to some sort of spring and key in the hub, rather than the clip arrangement (I can't quite picture the setup at the moment)? I know it would be a bit of machining but may be worth it if it's a recurring issue.

[260DET]

Z32 gearboxes were upgraded a while back, from memory, stronger 5th gear, extra syncros.

[Noddy]

There is a few people Ive spoken to in the last few days who have done similar things with good results. Tig welding extra material in at the top, machining it back to make a slipper pad has been a suggestion too.

I spoke to a guy who worked on the groupA 32's, They used hollinger inturnals. We spoke to Hollinger not long ago about getting some gearsets made up for the Nc RX2's we run (Hollinger used to make them a few years back) but, they were not interested... unless we were going to order 1000 sets. I fear that the gtr stuff will be in the same basket.

lol, and nissan are out of the stupid clips and 3/4 syncros....

[sweefu]

Z32 gearboxes were upgraded a while back, from memory, stronger 5th gear, extra syncros.

Only the late model Z32 boxes were upgraded, 1998+ from memory.

[Duncan]

because you've personally killed them all!

sorry I am no gearbox expert but with the GTR box I do know there were changes for the last series (series 3 r33), and that the old design was made obsolete. Since the internals are similar/the same are there any series 3 changes you can apply to your box?

BTW great to hear the old girl is still hustling around tracks nicely

[Noddy]

yep, She has had 2 years sitting in the corner. I picked up a levin on my last trip to Japan and, it has distracted me for a little while. There is a new motor in the pipeline, a pretty silly 26/30. It's all together on the engine stand ready to go in the front cut that came off the black 33 (from the aust titles) for a fit out for a custom dry sump, mounts, piping etc. Then Ill just swap it into the yellow 1. You have to race at Lakeside some day. It'll blow your socks off Duncan.

[260DET]

Bought a brand new Z32 one from Nissan a couple of years ago. Some were being brought in from the US by individuals at a good price too.

Edited March 12, 2014 by 260DET

[PN-Mad]

Just to answer the question in the OP, the group A's use holinger boxes. Guess that answers the question somewhat...

[Noddy]

The changes made worked well at lakeside: however, I was in 4th and 5th for most of the lap there so whasn't much of a work load for the hub. The only time I had an issue was on a down shift when I messed the double clutch up with out enough revs.

[turboedsloth]

Have a look at upgrading to an R34 3/4 synchro/sliding hub setup, they use solid type key.

D22 navara's also use some of the same gear just under different numbers, but it is hit and miss with the models

[bigmikespec]

General question for those doing track days in R32/R33 GTR's... what gearboxes are you running and power are you racing with?

I am looking at some options at the moment; the OS Gearset seems to be the most cost effective with the 1-5 kit, billet shaft and billet plate totalling just over $3.3k... but I am not sure how many people are racing with them?

Anything after that like a PPG well you can multiply by x3 just to get a gearset without a billet shaft.

I am starting to think just be gentle with the stock one and put the pennies away.

[Noddy]

That's pretty much the same answer I have come to as well. For the moment any way.

[fatz]

only maitenance i do is change the oil every 10000km

[Noddy]

Mine is for sale. I'm going to a modified tremec 6 speed.