Tractive Sequential Dog Box In An Rb26 Engined Gts-t

[Chris Wilson]

I made brief mention of this ages ago in a thread about PPG gearboxes that appears to have hit legal problems. I was asking about PPG dog gear kits for a stock GTS-t casing, but, in the end, and nothing to do with comments favourable or otherwise about PPG stuff, I did something unique, and I document it below. The car is a GTS-t that I have built an all new, all steel RB26DETT for. I have already sorted the suspension and brakes, those interested in that side of things may find pictures on my (slow, home PC) FTP site at ftp://ftp.chriswilson.tv in likely sounding folders.

To save a lot of duplicate typing I have copy pasted the salient info from a UK Skyline forum. It may scan in relation to time a little oddly, but there you go, it covers a few months work, waiting and fiddling, not to say the expenditure of some money. I hope it's of interest, the car still isn't finished, but long term, when this is shaken down and sorted I have bought a brand new R33 GTR shell in Japan, and I will be having a full weld in multi point cage fitted, and the car will actually be raced, as opposed to the track days it has been used for previously. My wife has persuaded me I should reinstate my competitive racing, as I am spending too much time in the pub, and she misses the racing.

Here we go then:

My RWD gearbox is built, it's a Swedish made Tractive sequential dog box for my R33 GTS-t I used a modded auto box bellhousing and a concentric clutch release cylinder set up, to work on a Giken triple plate clutch and flywheel. Total weight of bellhousing, adaptor, slave cylinder and gear lever, with wiring and indicator box is under 37 kilos, I can get some more weight off the bellhousing, so I am pleased with that. The gearbox also sits low in the chassis, the way I have orientated it, which all helps the C of G.

http://www.chriswilson.tv/tractive/tractive.html

Edited October 2, 2009 by Chris Wilson

[Chris Wilson]

I managed to do a dry build and see if my measurements for clutch release bearing clearance needed fettling. They do, but it's just a simple matter of turning 1/8 inch off the concentric release bearing spacer and refitting it. Everything else seems spot on, it's low in the bodyshell, and looks tiny compared with the OE Nissan RWD box.http://www.chriswilson.tv/box_on_engine/box.html

[Chris Wilson]

I finally had a couple of days to make the rear mount and dummy up the installation in the shell. I have managed to keep the stock R33 GTS-t gearbox crossmember and the stock rear gearbox mounting, albeit using a Nismo (harder) rubber mount. I now need to make up a propshaft using front and rear C/V joints, and I will probably use one in the middle as well. Finally the gear selector linkage (sequential) needs fitting. It will come from the gearbox through the roof of the tunnel, to a ball bearing quadrant, and then forwards through where the radio might sit, to the new gear lever mounted on the alloy plate over the standard gear lever tunnel hole. I have put a few pics up at IrfanView HTML-Thumbnails

There are some new photos of this model gearbox on a test bench showing the internals, plus the selector lever assembly and dash gear position indicator unit at

IrfanView HTML-Thumbnails

[Chris Wilson]

I have had a few people ask the price of this transmission, it was about £9500 with a bellhousing adaptor, gear lever, linkage kit and electronic indicator But like all proper race boxes you get what you pay for, and they have brilliant re sale value. I have other future projects in mind that can use this transmission, so it's not TOO big a luxury, long term. Tractive are a dynamic and modern company with an English technical sales director for their motorsport division, they have been so helpful as to make some UK race transmission companies look absolutely appalling in their customer service. There's not much English language stuff about Tractive, but here's a lengthy YouTube video. Bear in mind they were initially set up to make high end concrete cutting and masticating equipment, then got into motorsport transmissions.

I have no connection other than as a very happy customer.

There's also a video of a Millington N/A Cossie Sierra engined Corolla with a tractive box, this one with an optional paddle shift conversion, so you can change from the steering wheel or lever, it gives an idea of how fast a modern race sequential can change.

Tractive, the company:

Tractive gear box in use:

[Chris Wilson]

It's very light, with a custom bell housing I could have got it at least 14 inches further back. It's so light, my wife Jane can pick it up quite easily.

Edited October 2, 2009 by Chris Wilson

[Chris Wilson]

Spent the whole day, albeit with a hangover, in the garage making the mount for the gear change quadrant to fasten it atop the transmission tunnel, finalising the rear gearbox mounting bracket, and making the base plate for the gear lever itself and mounting the plate where the old automatic gear lever assembly fastened to the tunnel. I am trying to do the whole install with as little modification to the shell itself as possible. The idea being that if I find a mint shell for very handy money I can send it to have a weld in cage fitted and swap the bits over without having to fiddle about with the shell itself very much. Will take some pics tomorrow. I need to get the sound deadening stuff off the top of the tunnel as I want glue and bolt the quadrant plate to the top of the tunnel stiffening the sheet metal locally. There will be a fair anmount of leverage on this quadrant and I don't want the tunnel sheet metal working and cracking. Access is limited, it's through the radio double DIN aperture plus another 4 inches above that where the heater control panel has been removed temporarily. I MIGHT be able to get the heat gun in there, or I was thinking of sending `er indoors to B&Q tomorrow for a plumbing freezer spray. I am told if you freeze this stuff it will chip off quite easily? To gain total access the whole dash would have to come out, and I am feeling idle

I have also ordered a C/V joint and boot from GKN Motorsport, having found Nissan use a 108 mm C/V joint and a GKN type 28 spline prop shaft end. Nissan only sell the propshaft as 2 assemblies, and they are mega money new. I have decided to have a go at making a custom propshaft myself, and just paying for it to be balanced professionally. The stock GTR (4 wd) rear propshaft has gone on my GTS-t (2 wd) with just a swap of the centre support bearing cage. So I have a C/V joint at the diff end, and one in the middle. The GTR front half is about 16 inches too short, and uses a Hardy Spicer (cross type joint) onto the GTR gearbox. This box has a C/V joint flange on it, so I am cannibalising two old GTR front propshaft halves to lathe the splined end caps off, I'll then make a jig and weld the end caps onto a longer tube. I then end up with a longer front propshaft half with a C/V joint on each end, so the prop has 3 C/V's instead of two. It's this sort of stuff that takes a LOT of time and planning!

http://www.chriswilson.tv/propshafts/propshafts.html

[Chris Wilson]

Finished the gear lever and linkage assembly and fitting today. Took from 9.00 AM to 6.15 PM, thanks God I am able to do this stuff in house, the cost of farming this sort of stuff out would be horrific. I'll get some photos up soon, it's worked out quite well, I feel, given my reluctance to butcher the shell any more than is vital.

I am now ready to have a go at the prop. Tractive sent me a plain gearbox flange, ordered Friday, here Monday at 8.30 AM, not bad from Sweden, it regularly takes me longer than that to actually speak to anyone in the know at Quaife here in the UK

I now have the option of a C/V joint at the gearbox end, or a stock type Hardy Spicer cross joint. The GKN C/V came this morning, too. A bit of a problem, the inner part is perhaps 60 thou inch thicker, so although it fits perfectly on the splines of the Nissan shaft, you can't get the circlip on. I see two options, machine the shaft end to allow the joint to go 60 thou further on, or grind the centre of the joint 60 thou thinner. I prefer the latter option I think. There's a raised area on the centre forging almost 60 thou thick, I can lose that quite easily. It won't affect the kinematics of the joint at all.

[Chris Wilson]

I have bunged a few new photos up at http://www.chriswilson.tv/gearbox_installa...thumbnails.html

It may not look much, but it's taken ages, basically I took an auto box bellhousing from an automatic R33 GTS-t and then made an adaptor to mount the Tractive sequential dog box to it. I also made an adaptor to run a concentric clutch release bearing mechanism totally within the bellhousing, as it gives a much lighter pedal (no GTR clutch servo needed even with the triple plate Giken clutch and lightweight (modded) flywheel fitted. I then made a gearbox rear mount from sheet steel that picks up the `box around the propshaft output shaft bearing flange. A 2 piece propshaft is now being dummied up ready for fabrication and balancing next week. I also fitted GTR alloy rear uprights, with the GTR big drive shafts and hub bearings. The diff is an R34 GTR one as it's the only one with a ratio to give a sensible top speed without an over driven top gear in the `box. The rear subframe is solid mounted, and the diff itself is on NISMO HD mounts.

The gear lever mounts to a Dural plate that fits the unmodified tunnel aperture. The quadrant that turns gear lever motion through 90 degrees has to be very sturdy, there are serious forces here. I made an alloy tube with a flat milled on one end to take the quadrants 8mm bolt, and this mounts onto the transmission tunnel via 3 6mm bolts coming from underneath the tunnel. I have re inforced the tunnel sheet metal locally with a 16 gauge steel plate that's glued and bolted to spread the load. I may yet triangulate the top of the alloy tube back to the gear lever Dural base plate with a small section tubular support rod to stop ANY flex. I managed to buy a brand new GTR shell from Japan the day before yesterday, the long term aim is to have the new shell fitted with a proper weld in roll cage and just the basics fitted for track usage. I think the stage has come for some proper shell safety and rigidity, for both my protection and to get the suspension working properly. At the moment the shell itself is probably 1/2 of the suspension compliance

[Chris Wilson]

Well, that's a few months work and messing condensed into a quick resume. Hope it's of interest?

[Chris Wilson]

I had a sudden change of mind regarding the propshaft after discussing it with some transmission engineers. They reckoed three C/V joints may allow the shaft to hammer fore and aft under certain conditions, and suggested I duplicate the stock Hardy Spicer joint type arrangement at tge gearbox end. I had Tractive supply an un-machined output flange (that came on the Monday after speaking to them on late Friday afternoon before, not bad from Sweden to the UK...). This is now drilled to take a bigger than stock, cir-clipped, not peened, joint. It's away for balancing, and I forgot to get a photo after I built it. Should be OK, hopefully. I now have a spare new GKN CV joint, but it'll come in for something no doubt, in fact it will replace any worn Nissan ones in future, so no worries

[9krpm]

Thanks for sharing Chris.

Wow the gearbox looks very small and compact.

How much power is it rated?

Do they have any plan to make a GTR gearbox for you?

[Birds]

A truly awesome setup mate...looks like she'll serve you well. Don't think I could part with AU$20k for a tranny but I'm sure you'll get your moneys worth on it