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ScottieGNZ, Don't be AFRAID (PICS)!


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Yes and no. The clutches that send power to the front diff are "actuated" by fluid pressure. There are several accelerometers throughout the GT-R. They feed into and take inputs from a few of the computers throughout the car. They then feed signals to the ATTESSA pump and valves which control how much torque is transmitted to the front driveshaft. In otherwords, you need to transplant all the accelerometers, computers and pumps to make it work. It adds more weight, and most certainly more complexity. -Bob

 

Ok, if I can't find a way to control a stupid pump and perhaps some valves I am an engineering retard. No offense to you Bob, but my philosophy is this. If someone says it cannot be done, they are most likely just too lazy to try! That is in no reference to you. I don't car about traction control, I only want to adjust the ratio of drive front/rear. I could be wrong, but I will dig deeper when the time comes.

 

There is no need to move the front diff, as it is already toward the front of the motor and in the correct place in relation to the Z engine bay. Before you even think of the AWD transfer, look very closely into how you will get the AWD to actually work. The fabrication/grafting isn't all that hard.-Bob

 

Someone posted a pic earlier and the output flanges are dead center on the engine, between the #3 and #4 cylinders. That would mean my engine would be sitting where the radiator normally goes in order for the cv's to line up with the wheels. It may be necessary depending on the location of the gear shifter on the tranny. Otherwise the pan must be sectioned and the diff moved forward.

 

You said: " with some electronics" Granted that was in relation to turning off the FWD portion' date=' but the ATTESSA system most certainly has "some electronics" and don't forget that all the manual's and diagrams are in Japanese. Yes, there is a firm in Australia that will sell you a factory manual that is translated to english. However, noone has been able to tell me if the electronic diagrams are translated as well.....

-Bob[/quote']

 

Ditch the stock wiring harness crap and rewire it yourself. I would only go with an aftermarket fuel management and tune the thing myself. As I said before, if I can't find a way to control a pump I am in sad shape.

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Guest MoNkEy

240z Turbo, what type/size piping did you make your intake side piping out of?

 

We will be doing a bunch of custom fab'ing for the datsun.. if my friend gets one, might as well practice now..

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Don't forget one very important difference between what you would hope to accomplish and what I am building my car for. Yours is nearly all drag racing, where mine is 100% road race. Therefore setting the AWD torque transfer to one setting accomplishes little for me other than making my car a 4WD car and I lose the benefits of the AWD. Therefore, I would have to find a way to make the ATTESSA work for it to be viable for me. But a simple manual pump system,(such as the HKS) would work very well for you in a drag race setting. I understand you weren't talking about me and am not one to say it can't be done. However, it was clear you hadn't looked at what was required so I shared. Anything can be done with enough stubborness and money/time. And here is some more food for thought, the yaw sensors and accelerometers are calibrated for their particular location in the GT-R, and if not placed in the same location in relation to the CG/center of moment,(or whatever the correct term is...) their input to the stock computer would be inaccurate.

I have intentionally kept some of the details of my suspension work secret waiting for the articles to come out. As such, my approach is very different from anything you will ultimately set out to do.

I have yet been able to find someone who can tell me to what extent the ATTESSA computer uses the other computers in the car to make it work. I don't even know if it uses the stock ECU. All of this was moot when I found it added even more weight to my transplant as the motor and tranny alone is 200 lbs more than the stock L6 and I am trying to minimize the extra weight.

But I did just wander out to my garage and take a close look at the motor and the old oil pan/diff. You are correct, the diff outputs are about the 3-4 cylinder range. You can put the motor in that location,(where the outputs would line up with the existing wheels) but it will shift the motor closer to the radiator support,(but not quite in the radiator space). The gearshift fits nearly perfect with the motor all the way back near the firewall. It would still fit with it forward 2 cylinders, but would put a fair amount of weight over the front wheels. And with the RB26 in my 260z, the shock towers are centered about the #2 cyl. If you start moving the front diff in the oil pan, now you are getting into some pretty major fabrication, as you can't use the GT-R front subframe, etc.. It can be done, but you might be approaching a $20k+ swap just for the driveline front and rear. You want 9's, and with good power,(easy in the RB26), swap a rear suspension that can handle it, you got it. I think it would be much easier to swap just the rear suspension from another car so it can handle the hard launches and power. It has been done with a Supra rear end, of course a corvette rear setup, and after looking, the 300zx setup would swap fairly easy. In the end, it would still be an engineering challenge, but you might actually drive the car before 2010.... I won't tell what I am swaping in yet, but it is none of those. :)

-Bobby

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For those who want to know more on ATTESA and how alot of the AWD system work go to the link below. It shouldn't be too difflicult to figure out how the pump operates. It is probably variable voltage, 4-20ma control circuit, or mabey even variable frequency. If James was paying attention during his controls class instead of making paper airplanes he should have no problems :D:D

 

http://www.geocities.com/gkurka2001/CarTech/tech_traction_4wd_2.htm

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ive posted this in several different areas but i have successfully swapped a z31 rear into the car without adapters using the z31 stubs. i machined the strut housing to accept bearing that fit the z31 stubs and had custom shorter cv axles made from the z31 examples, made up some brake adapters and now basically now have the entire z31 rear suspension minus the struts themselves ;>

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Stony, most of us nuts know about your swap. However you are about as mobile as I am right now, i.e. not. The proof will be when you start cranking it down the 1/4 mi soon.

James, I for one would love to see the full AWD setup with the ATTESSA working properly in a 240z. I would likely follow your lead and install it in my car after you figure it out..... :) But I think it would be lighter and better for you to put a manual setup in.

-Bob

 

edit-speeling..

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Thanks Bob and Stony. One thing to consider about using a stronger diff in the rear...the ratios need to match that of the front diff. I am sure it is in the 4.## range. You can always run varying diameter tires to compensate. As far as sectioning the diff. That should not be difficult at all from what I have seen. I looked over the RB very carefully while in New Zealand as a shop had on on an Engine stand. I fell in love! FYI, I started my car today. Ran for 30sec and then died. DOH, didn't have time to figure it out as I am fabbing a 304SS header for my buddies Honda N/A race car. Will post some pics tomorrow when finished!

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