got the rb26 stagea on the road finally :) few dramas, this is RB26VL btw

[StageZilla]

hey guys well i been unable to log on to here for months for some stupid reason so i change my user name from RB26VL to this now

the stagea was completed about 6 weeks ago and all was well until we realised it was only in 2wd mode and we had removed the ecu from behind the rear quarter panel which is infact the attessa control unit, i was told it was the auto ecu, but we plugged it back in and then 4wd came on, and light is still on on the dash but its CONSTANTLY staying in 4wd and we cant work out why??? im talking 4wd from idle, and only way to get 4wd is remove the rear attessa hydraulic line and put a stop on it and then its in 2wd, but why would it be in 4wd ALL the time?? also heading down the freeway, dropped it to 2nd gear and planted it to revlimiter of 7500rpm and auto tranny fluid from the transfer case is spraying through the gearbox shifter and in the car, because i didnt have the console surround on, but it only happens at redline or close to it, and only done it twice plus it seem as if the fluid is almost boiling, cause its in 4wd maybe???

besides all the recent dramas the bloody thing moves really well, in 2wd mode it just steps out on every gear change, cant wait for the 2530 turbos to be done soon :aroused: people are just amazed how fast volvo lookin wagons can go :wassup:

no dyno run as yet as we couldnt get 2wd to work for the 2wd dyno the shop had so we gotta sort this out first but hoping around 360-370hp at wheels, which is same as the vl with a few less mods. u can definately feel the wieght of the stagea compared to vl but quality makes up for it hoping to get the a weigh bridge in the next week to weigh it with everything in, prolly around 2000kg with subs etc hehe, cant beleive a 2.6L can go so fast dragging along a big car :headspin:

sydneykid or anyone hopefully u's can help

thanks a heap guys

[CSV Imports]

Glad to see it on the road! Post some pics of the finished product for us!

[Sydneykid]

I would overlay the Stagea ECU pinouts with the GTR ECU pin outs, I think you will find one of the sensors that the ATTESSA uses has a different location on the Stagea loom.

These are the R32/33 GTR pin outs I would be checking;

Pin 7 - tacho

Pin 38 - throttle opening

Pin 48 - throttle sensor power supply

Pin 53 - vehicle speed sensor

Pin 56 - throttle sensor output

[StageZilla]

thanks for the quick reply sk

so this is the attessa ecu plug u r talkin about?

also remembering i have autronics smc ecu, rather than stock gtr ecu, is that any reason for probs or not?

so what wires from the original wiring loom have to be hooked up?

sorry im not real good with the attessa system, can u explain how the sensors affect the control of the attessa?

thanks again, u r a great help

Brad

[Sydneykid]

thanks for the quick reply sk

so this is the attessa ecu plug u r talkin about?  

also remembering i have autronics smc ecu, rather than stock gtr ecu, is that any reason for probs or not?

so what wires from the original wiring loom have to be hooked up?

sorry im not real good with the attessa system, can u explain how the sensors affect the control of the attessa?  

thanks again, u r a great help

Brad

Hi Brad, I am not really an ATTESSA electronics expert, I am barely OK at the mechanicals. But from what I understand the ATTESSA ECU (AECU) uses some signals from the engine ecu (EECU). The logical ones are road speed, engine rpm and throttle position, hence my previous post.

The AECU uses two G force sensors, one front to rear for accelleration and braking and one side to side for cornering. My limited understanding is that the AECU takes those G forces readings adds them to the EECU inputs and decides how much front drive is required according to its programmed map. It is not a simplistic wheelspin comparison (like most of the front drive 4wd's) using the ABS sensors. That is why the ATTESSA system was so successful for circuit racing, it was designed for that purpose.

I don't know how the Autronic was wired, there are a number of possiblilities;

1. Use an adaptor between the standard wiring harness an the Autonic

2. Use a dedicated Autronic wiring harness and ignore the standard wiring

3. Cut off the standard EECU plug and rewire the standard harness into the Autonic plug

4. A combination of the above

If the AECU is indeed missing some inputs it may simply go into "limp home mode" and apply 100% 4wd. Which sounds like what you are experiencing. Although it would appear from the excess pressure (you are seeing) that the hydraulic pump is running flat out, which seems a little extreme. I would be closely checking the AECU wiring first, particularly that to the pump.

Next you need to check that the wiring to the AECU still has output from the EECU. These are easy to check with a multimeter, obviously throttle opening is a simple voltage movement when you press the throttle. RPM and Speed sensors are both a pulsed signal. It would be easier if you had an AECU pin out schematic, sorry I don't have one here. Maybe someone else can post it up for you if you don't already have one.

Hope that was of some help:cheers:

[StageZilla]

thanks sk that gives me a better understanding, well the autronics has its own dedicated loom (supplied with ecu) and we wired it to suit, so no stock loom in place.

we will be checking the attessa ecu tonight hopefully, and some wiring diagrams would be of great help if anyone else can get hold of em?

thanks a heap again

Brad

[StageZilla]

well just pulled the attessa ecu out and the diagnostics light says 75 as a error code, so what is that, anyone know?

cheers

Brad

[Sydneykid]

Hi Brad maybe post it up in the Forced Induction Performance section. More people will have a GTR workshop manual than a Stagea one.