4wd

[OoskylineoO]

Hey guys, Ive been reading few threads about the 4wd system in a r33 gts-4. theres been few different comments and im confused lol..im trying to figure out how the gts-4 4wd system works..is it RWD until u make a turn then 4WD kicks in for control or is it 4WD all the way and neva turns off? lol is there some sort of torque split?

[Godzilla32]

The Attessa E-TS system calculates its operation from a number of sensors such as the ABS wheel sensors, on-board G-sensor, etc. It uses these inputs to calculate upto 100 times a second if it will be beneficial to provide front torque. So basically if you enter a corner and the Attessa E-TS computer thinks you need assstance it can send upto 50% of torque to the front wheels to correct and stabilise the car.

So yes it is rear wheel drive biased, which means until you really need it the car runs in rear wheel drive then has the option to start providing front torque depending on the situation. It does this by using hydraulic pressure in the transfer case to apply clamping pressure to wet clutch packs. The more pressure it applies, the more torque is transferred to the front wheels. It uses a fluid similar to automatic transmission fluid (ATF) to achieve this.

Even for present day its a very advanced system and most people dont really understand how it works completely. I have a GTR and thats what my info is based on but im pretty sure the GTS-4 is the same system, however the Attessa E-TS is tuned differently for different models.

Regards,

Deren

Edited July 24, 2007 by Godzilla32

[Rob_C110GTR]

Nissans 4WD system which transfers power and braking force where it is needed for best performance. Torque is split between front and rear wheels while braking force is split independently to all four wheels utilising ABS. In ordinary driving conditions torque is delivered purely to the rear wheels, however when the car is pushed the computer engages the front wheels and calculates the amount of power split between front and rear.

Edited July 24, 2007 by Rob_C110GTR

[Slim Mat]

If it's anything like the GT-R's it is computer controlled

Try http://www.jbskyline.net/R32/GTR/index2.php#attesa

There is a bit of a write up there

[GTR32GUS]

the r33 have at least 5% going to the front wheels all the time

The basic way attessa works is to put minimum power to the front wheels through the corner so u have the handling of a rwd car and power to all wheels as u leave the corner so u have the grip of a 4wd car

Edited July 24, 2007 by GTR32GUS

[Godzilla32]

If there is some power going to the front wheels all the time, there is a problem. If you research it you will find it is not mean't to have torque all the time. One common way of tricking the Atessa E-TS system is to fit staggered tyres front to rear, instead of the same width all round as it should be. I have heard this can bring on more front torque earlier. I think doing this is also known to run front torque constantly too. So this maybe why you have the minimum of 5% front torque. Could also be something to do with air in the system. If you read the DIY section there is the procedure for air bleeding of the 4wd system. However as i previosly mentioned the different model skylines with the Atessa E-TS system have it tuned differently, but only to bring in more front torque earlier, not all the time.

Regards,

Deren

Edited July 25, 2007 by Godzilla32

[OoskylineoO]

O ok, well thanks for that guys..I have a 97 S2 r33 GTS-4, so basically my r33 has the ATTESA-ETS system running similar to that of the GTRs except tuned differently for when front torque is transfered hey? and btw, what fluid do I top up the system with? that bottle in the boot on the drivers side..I heard I could use Nissan ATF fluid?

[Godzilla32]

Nissan recommend to use Nissan D-matic fluid. Im not 100% sure if its safe to use normal ATF (Dextron) or if they just want the money coming back to them. Unless its hell expensive, id say use the nissan stuff just to play it safe. If your feeling adventurous you could even bleed up the system to make sure its working as well as it can be. See the DIY section.

Deren

[Duncan]

Deren 33 and 34 system always has some front torque, only 32 had 0 front torque most of the time

I use normal ATF for the transfer case, castrol syntrax in the race car.

[OoskylineoO]

Hey guys, i THINK there something wrong with my 4WD system, my 33S2 GTS-4 makes a high pitch humming/whining noise? sounds like its coming from the back driver side. Could this be a pump for the ATTESSA-ETS or something? is it normal?..and also my 4WD dosen't feel as good. I took it out 4 a test around a corner and my 33 skidded abit and felt as if no torque was delivered to the front D=..I checked the fluid level in the boot and its bout 5mm under MIN level. Is that the reason why my 4WD is making noise and not working properly? or shuld I try bleed the system aswell?

thanks for ne help!

[Godzilla32]

Oops ok sorry my mistake. I'll just stick to the 32's huh lol...

I would top up your fluid and give it a bleed as its detailed in the DIY section or manual if you have it.

The noise you are hearing is probably coming from the transfer case as its positioned to the right side.

[OoskylineoO]

o ok, thanks for that. might give it a try. if the noise is from the transfer case if there anyway to quiten it down? or is it normal lol..1 more thing..is the 4wd in the r33 meant to engage almost instantly?. I skid 4 about 0.5-1sec and dont feel any front torque :S

Edited July 29, 2007 by OoskylineoO

[Duncan]

well, thats hard to answer. 4wd can't fix an understeer problem so ATTESSA might be doing its thing, but it can't create more grip overall than the 4 tyres can give. You need to think about what is sliding (front, rear) and why (power, lateral or sideways motion?)

Bring it by the next sau track day and we can see if it is working ok

[Godzilla32]

Hey might mean when he launches it. In that case it possibly needs a bleed. Still, you need to you work out if infact its just the rear wheels spining or all four. Another thing to consider is the health of your clutch, being 4wd it places alot more load on your clutch during hard launches. I know myself that hard shifts wont always make a clutch slip but hard launches will with the grip four wheels provide.

A whine from the transfer seems to be fairly normal.

[OoskylineoO]

well o ok. hmm. It feels like a holden or ford when I take it quick around the corner lol..the rear spins and slip light comes on. Or maybe I didnt go around that corner fast enough? lol

[Public Enemy]

i find the best way to check the 4wd is working is to look at the gauge. Also there is an orange 4WD warning light that comes on if there is a problem.

Next wet day accelerate hard away from the lights, if your wheels start spinning the torque split gauge should go up as the computer transfers torque to the front wheels. It should work in a straight line not just around corners.

[OoskylineoO]

Don't think I have a gauge, mines a r33 S2 gts4, hmm mayb i will try that hey lol. how long does it take the ATTESSA to enage? almost instantly? or .5-1s?

[Godzilla32]

Should be pretty quick but as Duncan said there should always be 5% front torque in the r33 so your car should wheelspin even less than an r32 with the different programmed Attessa seeing as its always engaged to some extent...