R32 Gtr Attesa-ets Testing?

[skylimit]

Hey all!

I know this topic has come up before, and I have read them all, but I just need to clarify how would you know

if the ATTESSA-ETS system is working at optimal performance when you buy an R32 GTR?

What would be the signs of a healthy ATTESA-ETS system?

What would be the bad signs of a ATTESA-ETS system that is not working properly?

Cheers guys!

[Duncan]

Well its easy to tell if the system is all OK, if not the ATTESA light will be on on the dash.

However its much harder to tell if it is really healthy, because even if the system is working fine the centre clutch packs do wear, the system will think it is giving front torque but the actual torque transmitted might be minimal.

[Gav]

If you get the car dynoed in 2WD, leave the dyno unlocked and re-install the fuse and try and drive off the dyno.

If the clutch packs are in good nick, the car will drive straight off. If they are worn or slipping, it will move off more slowly (or not at all).

A subjective test I know, but if the dyno operator sees a lot of GT-Rs, he'll have a pretty good idea.

[skylimit]

That's good advice: I'll give it a try!

What wbout the torque gauge? If the needle is slow to pick up when you give it a bit, couldn't that be a sign of an unhealthy attesa system?

I heard a healthy system, snaps the needle quite fast to full front torque load under max rear slippage.

What are your views on bleeding the attesa-ets system? I have heard that corrects many of the problems associated with no or low torque conversion to the front.

How do you know when your clutch packs are wrecked?

All opinions welcome!

Edited May 11, 2006 by skylimit

[Duncan]

Well if the torque gauge is moving slowly that suggests that it is not bleeding or the clutch packs....the gauge reflects what the system is trying to do.

Maybe your longitudinal accelerometer is failing? I've not come across that problem but it must be possible/

[Swiper the Fox]

Well if the torque gauge is moving slowly that suggests that it is not bleeding or the clutch packs....the gauge reflects what the system is trying to do.

Maybe your longitudinal accelerometer is failing? I've not come across that problem but it must be possible/

The torque gauge actually has nothing to do with the mechanical side of the system. A completely stuffed transfer case will not be indicated by a lazy gauge, as the gauge signal is derived from an electrical output of the ATTESSA ECU it will still work, and should not be relied on.

We use a 80psi pressure gauge on the hydraulic line feeding the transfer case to make sure at least 50psi to 70psi (will vary depending on load) is present when front drive is operated. If this is ok then the transfer case is the problem (clutches worn or hydraulic actuator failure).

Hope this helps.

[CruiseLiner]

The torque gauge actually has nothing to do with the mechanical side of the system. A completely stuffed transfer case will not be indicated by a lazy gauge, as the gauge signal is derived from an electrical output of the ATTESSA ECU it will still work, and should not be relied on.

We use a 80psi pressure gauge on the hydraulic line feeding the transfer case to make sure at least 50psi to 70psi (will vary depending on load) is present when front drive is operated. If this is ok then the transfer case is the problem (clutches worn or hydraulic actuator failure).

Hope this helps.

hey paul do u happen to have a pic of how u plumb in a pressure line off the main hydraulic line??? sounds like a damn good idea and worthwhile as i dont even have a torque split gauge in mine (stagea).

[Swiper the Fox]

hey paul do u happen to have a pic of how u plumb in a pressure line off the main hydraulic line??? sounds like a damn good idea and worthwhile as i dont even have a torque split gauge in mine (stagea).

its a simple matter of installing a "T" fitting at the rear of the box where line attaches or getting Pirtek or any other reputable hose doctor to install one in the line and cap it off when not in use.

[giant]

its a simple matter of installing a "T" fitting at the rear of the box where line attaches or getting Pirtek or any other reputable hose doctor to install one in the line and cap it off when not in use.

paul is 100 % correct and its the only real way to test it properly.

[CruiseLiner]

hey paul cheers for that, so a regular oil pressure guage will be fine with a 0-100psi readout or does the pressure go higher than 100psi?

also on the r32 system vs the later model ones that hold the pressure..

does that mean the r32 gtr would read 0 psi when not operating 4wd and r33 and 34's would still have how much pressure when in 2wd?

Edited May 15, 2006 by CruiseLiner

[Swiper the Fox]

hey paul cheers for that, so a regular oil pressure guage will be fine with a 0-100psi readout or does the pressure go higher than 100psi?

also on the r32 system vs the later model ones that hold the pressure..

does that mean the r32 gtr would read 0 psi when not operating 4wd and r33 and 34's would still have how much pressure when in 2wd?

Yes a 0-100psi gauge will do the trick. As for holding pressure on the later models....its the preload on the clutch plates in the transfer case not the pressure applied to the ATTESSA hydraulic actuator (rear of transfer case) that is the problem on newer models (this is why you cannot dyno R33 + R34 models in 2 whell mode without removing driveshaft). You should have 0psi pressure when in 2wd mode.