Center Clutch Gtr R33. How Strong ? How To Do The Torque Splitting ?

[jogge]

hi,

i own an escort cosworth and we have installed an R33 GTR gearbox.

how strong is the center clutch ?

is it correct that the gearbox is running in rwd mode, and only if there is a pressure between 3-5 bar at the center clutch, it´s in 4wd mode from 100% up to 50:50% ?

do i need an controll unit to do the torque splitting ?

i will not leave the center clutch/diff in rwd mode and i will put it in 30:70 awd mode. is it correct that the center clutch will break even earlier ?

is there an uprated center clutch on the aftermarket ?

later i want to install an ppg box. do they have an uprated center clutch/diff ?

the car is about 700hp/800nm @ 1400kg with yokohama a048 semi-slicks.

thanks guys for your help.

greetings

Edited August 4, 2010 by jogge

[doo doo]

Have you converted your cossie to AWD? The 'centre clutch' is a wet plate setup involving 7 friction plates and 14 drive plates, there's no aftermarket option. It's activated by hydraulic pressure from a pump triggered by the attessa computer in a GTR.

Assuming you're running RWD then you don't need to worry about the centre clutch as it is only used in transferring power to the front wheels, and has no involvement with transferring any drive to the rear.

Having said that, there's still bearings in the transfer case that the RWD driveshaft passes through- the transfer case has it's own oil pump for these so you need to keep the auto trans fluid topped up in the transfer case.

Edited August 4, 2010 by doo doo

[jogge]

thx a lot for your answer.

the Escort Cosworth is originaly 4x4. it´s normally 30:70. so i wanna keep that, because the front diff is the weakest point of my drivetrain. only RWD is not possible because i drive the car at Nürburgring-Nordschleife and the Hockenheim-Ring. so it must have 4x4 to transfer all the power to the road. and also it´s really beasty to controll an RWD car with 700HP.

i read something in the prep. manual of an R32 as you say, that there is a hydraulic pump that is pumping oil to the center-clutch-mechanism of the gearbox. and i also read that it works between 3-5 bar pressure. so is it correct that a pressure of 0-3 bar is 100% rwd, and a pressure of 5 bar is 50:50 awd.

is it ok to get the system on 50:50 and holding that fixed, or does that also mean that the center clutch will break earlier ?

and what do you guys think of an genuine GTR R33 box about the power handling ?

for the beginning we have installed an used box only to do the installing. and now i wanna drive a few events @ hockenheim and nürburgring, to look if everything is working fine. but we are not sure about the power and torquehandling of such an box !

the car is 1400kg and is running on sticky semi-tires.

[jogge]

what kind of oil do i have to youse for the system with the pump for the torque splitting ?

i think i can use Castrol B373 in the complete box ?! and also in the torque splitting system

[doo doo]

The hydraulic system uses power steering fluid. The GTR hydraulic pump is not designed for continual operation, it burns out if left to run. There's also inputs that dictate what pressure it runs via the attessa computer. I'm not really sure what sort of end product you want re cost etc so maybe you could devise a way to keep the clutch pack preloaded either hydraulically or mechanically, you could also devise it in a way that it is adjustable in it's torque split, anything's possible with enough time and money.

The clutch packs should take the load, there's a chain drive i the transfer case but it's pretty strong, you'll more likely wear the clutches than break it for your application at a guess.

[Duncan]

interesting project....more pics and info!

fwiw I don't know anyone who has broken a transfer case on the track. Except me and that was an assembly/clearance issue.

[jogge]

on the dyno - 717,6 HP - 825,3 NM

tuning meeting switzerland

Hockenheim-Ring boxes

engine bay

Hockenheim-Ring.i missed the corner towards motodrom and had to go through the gravel on full throttle, to be in front of the second black evo without lights. the evo is running ethanol,Garrett GT35,680HP

sachs-curve

Nürburgring-Nordschleife.i was to early on full throttle after the karussel. and i hit the bumper...

facts:

- 2.3l 16V with KKK turbo

- engine is long studded with nicasil-wet-liners

- special crank,special pistons,longer rods..... compression ratio 7.5:1

- head fully ported and with bigger valves and crazy cams

- Pectel T6 engine management system

- 3 paddle AP-Racing carbon-clutch

- RaceLogic traction-and launchcontroll

- until now 6 speed R&D staright cut dog box. but broke three times......

- powershift system. shifting without clutch, only shortly cutting the ignition

- Bilstein/Eibach coilovers

- complete WRC front with adjustable anti-roll-bar and beams

- fuel catch-tank-system with two bosch high pressure motrsport pumps

- custom made fuel lines 12mm diameter

- 4 x 1000cc bosch injectors

- custom made intercooler

- 7.5 inch front and rear lsd diff 75% with special setup to suit my driving style

- WRC front bumper and rear wing.it is designed by adrian newey in the 1990´s.

- WRC cage by Heigo

- the car is front-rear on10.5 rims with 265-35-18 yokohama A048

the car is running a 10.56 on the quatermile strip in Bitburg-Germany in 2006.

the run was on yokohama AVS sport road tires,without power-shift, and without water-methanol injection.

the water-methanol injection is only used for cooling. not to run a more powerfull ignitionmap or more boost. i only wanna keep the acts in range of 35-45 C degrees to get always full power out.

Edited August 6, 2010 by jogge

[jogge]

to fit the GTR box we have made a plate with the exact fitment-figures of the engine on one side, and the exact fitment-figures of the box on the other side. everything was scanned by laser, so it shout fit perfectly.

- the transmission tunel was reworked. and also the clutch system is hydraulic now.

- the front prop-shaft of a skyline was shortened 20mm and fitted new joints.

- the rear prop shaft is the Cosworth 2WD one which we also shortened and fitted new joints on.

- the gearbox bracket is custom made

i have no pics of the work in the moment, but i think i can do some shooting later to get pics in here.....

Edited August 6, 2010 by jogge

[jogge]

here my car on the rollers:

the man behind the car:

the car is actually about 860HP/920NM

0-100 in 1.8 sec. / Quatermile 9.21 sec.

here the car of a friend of me, Hans Peter Laber. he won 5 times the austrian hillclimb championship.

the car on the rollers preparing it for the next saison.....

another good friend with his hillclimb Cosworth:

all cars including mine are built by Andreas Gabat and his Team: http://www.gabat-tuning.at/

all the hillclimb cars are running the strongest available 4x4 Quaife box.it´s sequentiell 6 speed dog engagement.

in the moment he is building up an Mitsubishi EVO 8 for Circuit and hillclimb. the car should be at 900HP. we will se what the future will bring.....

he has also one customer with the first GTR R35 in Europe.the car do approx 700HP and only mapped and a little soft changes around are done.

Edited August 6, 2010 by jogge

[jogge]

The hydraulic system uses power steering fluid. The GTR hydraulic pump is not designed for continual operation, it burns out if left to run. There's also inputs that dictate what pressure it runs via the attessa computer. I'm not really sure what sort of end product you want re cost etc so maybe you could devise a way to keep the clutch pack preloaded either hydraulically or mechanically, you could also devise it in a way that it is adjustable in it's torque split, anything's possible with enough time and money.

The clutch packs should take the load, there's a chain drive i the transfer case but it's pretty strong, you'll more likely wear the clutches than break it for your application at a guess.

for the beginning and testing i think i will use a normal electrical oilpump which we also use for kitkar projects. so i think with an pressure switch or pressurte valve i will adjust the pressure for the splitting.

but in the moment we are not sure at which pressure we have which kind of splitting ?

in the prep. manual i read about the testing for the mechanics if the system is working. and there it should be about 3-5 bar pressure.

but does that mean that 3 bar is 100% RWD and 5 bar is 50:50 AWD, or what ?

later when everything is fine, i think i will install the complete torque splitting system, with the wheel speed sensors, the g-sensor, and the splitting control box. i also wanna fit that together with the hks torque splitting controller.

that one: http://www.rhdjapan.com/hks-kansai-active-...3-15041?nflag=1

Edited August 6, 2010 by jogge

[doo doo]

You might have to do a little guesstimating about what pressure constitutes 70/30 split. As you've read the test mode will produce between 40 and 70 psi, but the system is able to run at 228psi. You have 100% RWD when the system is not engaged at all. If your hydraulic actuation is adjustable then you might have a little experimentation to find your optimum constant torque split value (i would personally start with about 40psi as i don't think the test mode produces full pressure)

Would it be helpful to have some pics of a disassembled transfer case all laid out?

[jogge]

yes that would be really helpfull to understand all the mechanic in it ?

can you please post some pics in here ?

thanks

but how do all the gtr´s handle it, if there running the quatermile. they do the burnout with RWD and then they switch to 50:50 or ?

but in 50:50 does also the center clutch break early or is the clutch then fully presst ?

because if it´s right what i read about the wear of the clutch in 30:70 mode it means that it will not hold that power so long ???

but my problem is that i dont´t wanna drive in 50:50 because the front diff is the weakest point in my drivetrain. and also i like the car more oversteer, for doiong a good job at the circuit. hhhhmmmmm.....

and another question. how can i identify if a box is a R32 or R33 box. the R33 is the better one because of the failure at the syncro´s at R32´s ?

[doo doo]

I'll have to dissassemble the case for you first then take some pics, will be overseas for about a month so might not have time till i get back, but i'll try to get some pics in the next week. Not sure about the boxes, heard of a few R33 boxes stripping 3rd, and most boxes have worn 4th gear synchros.

Dragging with the attessa is varied, you can burnout in RWD then switch to a preset split with a controller if you've set it up for this, or let the system work itself when you launch. But the track is different- I've read the earlier aussie racing (Gibson motorsport) skylines actually had a half second delay in the transfer off the start line so that the engine would be in it's best power band before the front wheels were engaged- they would spin the rears then suddenly launch forward as AWD engaged. The system is designed for track not strip.

Just remember that the rear wheel drive component is completely independent of the front wheel drive component, imagine that the fwd is added to the rwd. I'll get some pics up as they will explain much better.

Edited August 9, 2010 by doo doo

[jogge]

you don´t have to dissassemble the case. i think on the fugures in the workshop manuals are drawings of all the parts in the box. and i think this will help. i will discuss that system at the weekend with my mechanic.

[jogge]

hi,

i´m in contact with ppg for a complete R33 box. semi-helical gears with dog engagement.

the gears are rated up to 1000hp.

i wanna combine it with this shifter: http://www.nengun.com/ikeya-formula/sequential-shifter

what do you think about ?

i don´t want to spend money to firm´s without perfect quality and good service.

i don´t know the brands in the skyline scene, so a little help would be fine.

[doo doo]

Heard mixed reports about the ikeya shifter, but PPG is the go for gears, why not straight cut? You'll need to get in contact with the dude at PPG and see what he says about using that shifter with his dog box, I'm not sure he'll recommend it. I'm sure I've read that in forums here recently, do a bit of a search.

Have got a transfer case teady to pull apart so will be able to get some pics up for you soon.

Would love to see some pics of your awd set up and how you're getting the GTR system fitted up, so post em if you've got em.

[jogge]

hi,

i have fitted a 6 speed straight cut gear dog box before. and there we always have the problem that is called "bitings".

it means that the super-heat-threaded area of the flanks of the gears are worn out.

that always happens with straight cut boxes. so normally a straight cut box does not longer than approx 10.000km.

and also the semi-hellical gears are more stronger than straight cut gears, because the area of contact is bigger.

the only beneffits of straight-cut gears ist that they don´t loose so much power than the helical sets.and they are lighter.

in my cossi with helical gear set i loose approx 90hp. with straight cut gears it´s "only" approx 80hp.

and for example the super big awd box from quaife which the Gabat-Cossi´s use in hillclimb and circuit race is about 70kg.

the semi-helical r33 gtr box by ppg is about 95kg.

also you have to drive with gearbox-oil-cooling-system if you use straight-cut gears. because it produces much more heat.

and i don´t like the big noise of an straight cut box any more.

from my house to the hockenheimring is only about 1.5 hours by car. so mostly i go there for testing and driving in my cossi. i don´t use a hanger. so i´m always pissed off on the way back home.

of course i will post in some pics when the box is installed........

and i have already asked ppg for sequentiell shifters but they only advise me to look on the aftermarket. they don´t tell me a special brand......

Edited August 12, 2010 by jogge

[jogge]

the installing of the gearbox is nearly done. sorry but the camera was out of battery at the moment. but i will post pics at the end of the week.

but now we thought about to install the front and rear diff from a gtr because it is possible to manage a active torque splitting including the diff´s and gearbox if i install all the sensors and electronic´s from a gtr.

this would be fantastic, because it means it will be a complete active torque controlling system for "low" money.

the active diffs and controlling what was used in the WRC Escort Cosworth is a really big bag of money to spend to go for it.

so i think the choice of the diffs,gearbox and controllers of a gtr would be a good choice for "normal" money.

it´s really amazing what kind of potential the technical site of the gtr offers.....

[doo doo]

Pics of disassembled transfer case.....

you can see the main shaft passes through the hub which the chain drives off. This shaft is one piece from gearbox so you have all-time RWD. you can see the clutch plates act like an wet plate auto box to grip up the hub with the chain drive on it and transfer drive to the front diff. The 3rd shot shows the hydraulic actuation mechanism that pushes the plates together, and I've taken a shot which shows the hub spinning on the shaft. Also chucked in the completely buggered plates that just came out of the case which was previously in the car, you can imagine that putting in new plates has made a fair bit of difference to the drive.

If you can swap all the GTR attessa stuff over then that'd give you the best use of the system, the 2 diffs need to be the same ratio (you see it's a 1:1 drive from mainshaft to front drive shaft, GTR diffs are 4.111). Not sure what the cossie setup was like but with my GTiR AWD converted bluebird the diffs were different- the torque split of 60/40 was in the centre diff gearing. Just another thing to check but i'm sure you'll be on to it.

You could potentially use a hydraulic handbrake setup to set pressure on the back of the case, you can use different pressures then too. While you sort out putting the rest of the attessa of course.

If you need more disassembly pics let me know

Edited August 18, 2010 by doo doo

[jogge]

thx doodoo for all the help.

the pics explain much more than the drawing in the manuals. thx.

i will look after that special point on weekend, because in the moment i´m full of work.....

and for the diffs 4.11 is not so bad. the cossi is in the moment on 3.62.

but i will think if i have fitted the gtr box 5th is 0.75 or something. and on the cossibox 5th is 0.82.

so i think 4.11 in the diffs will also be perfect for my use.

how strong are the diff´s of the skyline ? do i have to use uprated diffs ? what kind of torque controll do the diff´s have ? is it lsd style diff ?

the active diff´s of the skyline do work as the system for the center case torque splitting is working ?

so it means i have to have also a pump-system on front and rear diff, connected to a controller (attesa?) ?!

Edited August 18, 2010 by jogge