Author Topic: S12_rb20det_4wd (Read 6359 times)

dangina · « **Reply #40 on:** 01:23:23 AM / 09-Aug-10 »

sweet! keep us posted!

RB25sx - SLPR · « **Reply #41 on:** 03:22:35 AM / 06-Sep-10 »

Any news in here??

nismologist · « **Reply #42 on:** 04:08:03 AM / 06-Sep-10 »

goodness... this is pure goodness.

what are you planning on doing with the car? rally reborn??

Nitro · « **Reply #43 on:** 01:32:48 PM / 07-Sep-10 »

I'll ask Valodka about it - I'll let you know about any changes

Vovka · « **Reply #44 on:** 03:10:15 AM / 02-Nov-10 »

Vovka · « **Reply #45 on:** 12:18:23 PM / 04-Nov-10 »

DjayS12 · « **Reply #46 on:** 05:03:43 AM / 05-Nov-10 »

Wow that widen the car quite a bit!

Running yet? that thing is totally insane I like it.. first 4wd S12 ever I believe!

SC S12 · « **Reply #47 on:** 07:27:39 AM / 05-Nov-10 »

on a side note :I dig those tail lights

Also this thing is wicked, throw some overfenders (and some front fenders) on it and call it done!
I really want to see this thing hustling around a muddy corner now

Vovka · « **Reply #48 on:** 11:38:09 AM / 06-Nov-10 »

tommy · « **Reply #49 on:** 01:34:15 PM / 06-Nov-10 »

man that require extensive modification to make the front axle line up with the diff... i wonder if it would've been easier to move the front differential backward, in line with the stock front axle by changing the diff mount and shortening the front shaft and then redrilling the oil pan for the drive axle to pass through in line with the new diff placement... In my mind, it would be easier than extending the whole body work forward a couple of inch.... and the wheel wells will probably need some modding in order to clear the wheels at full lock

*edit*

And looking at your pictures, you seem to have used a standard rb20 oil pan, I can't see the front differential and the the driver half shaft hole in the picture where you drop the engine in... how are you gonna send power to the front wheels???

RB25sx - SLPR · « **Reply #50 on:** 04:55:15 PM / 06-Nov-10 »

First of all let me state - I am not a hater. I love that you are putting this much time into an S12.. I just fear you may have bitten off more than is manageable. I have two primary concerns, and they both involve the 4wd system.

Now this is off a gts-4, correct?

The gts-4 and gtr share a common front suspension setup which uses a dual balljoint lower control arm (no bushing on the inner), and an upper control arm connected to a link bracket in the wheel well (dual bushings) - this is to correct caster and camber primarily (works in cooperation with the tension rod). What I am worried about is that you have moved to an S12/S13 variety suspenion which has only one balljoint, and an inner bushing.

So you chopped off the entire upper arm, and are planning on welding the coilover sleeve body to the side of it.. That is going to take some very thorough thought to get it even close to good enough. And even when it is put together you are likely going to suffer from random caster and camber changes which will make the car almost undriveable - no matter how stiff the front suspension since the play is inherent in the LCA.

My other concern is the Atessa wheel sensor system. From what I recall it distributes torque based on wheel sensor input - though on the gts4 it may have been a driveshaft mounted sensor for the rear wheels and 2 front reluctance/abs sensors on the hubs. Are these sensors being included, and since they are part of the chassis harness how do you plan to integrate them into your s12 harness?

Best of luck.

-Dan

Nitro · « **Reply #51 on:** 03:47:02 AM / 07-Nov-10 »

Let me reply for him.

As for the front suspension - it's still a draft. Not a final decision.
The Attessa system wont be here - there will be manual 50/50 - 0/100 switch for the first time, and after that he plans to make his own control module, that will distribute torque smoothly when starting.
As for the oil pan - he plans to finish the suspension first. Then he will swap oil pan and attach the drive shafts.

tommy · « **Reply #52 on:** 11:01:43 AM / 07-Nov-10 »

I also do believe that the first ATTESSA generation were using a speed sensor in the diff for the rear wheel...

Why go custom on a awd control system when you already have access to something that works and works good???

stick with the 2 speed sensor in the front hub and get a rear diff on a 240sx with ABS (yes you'll have to mod the mount and the driveshaft since it's a short nose r200, but you've got your rear sensor) and steal an ATTESSA control unit from a r32 and wire those shit on a custom harness (I don't really see the need to incorporate it into the s12 chassis harness) all you have to do is run a high pressure pump (electric or mecanical (lets say hook up an other P/S pump on the engine where the A/C use to sit)) and make it push ATF or power steering fluid (out of a small external reservoir) much like the standard ATTESSA that uses a pump inside the rear diff to provide the tranny with oil pressure to work the clutch that transmit power to the front axle... after this, the ATTESSA control unit will just adjust the amount of pressure that get to the center clutch and control eveything much like it does on any ATTESSA car

Because now all you've done is create a real complicated and real expensive 4x4 car... without a center diff, forget bringing this on dry pavement (ever heard about transmission wind up?), it'll behave like a truck when you've got the center clutch engage and when it's not, you've just got a hell of an heavier and much complicated Collin's car (the way it used to be)... and going custom on the awd control system is still gonna require to get some kind of oil pressure in the tranny to control the torque biais to the rear wheel and then figure out some kind of management for it... which will not be any easier that using what is already used in the r32 IMO

I'm not hating here and I absolutly love the idea, but I just don't think it's been thought through because if you don't solve the awd management, you've got yourself a pretty hard to make rwd car or a 4x4 truck... oh and I don't think he uses a rb20det from a gts4 since the oilpan has no axle going through it on the picture, so it's standard rb20det on a awd tranny...

Anyways, good luck with it

Nitro · « **Reply #53 on:** 02:40:43 PM / 11-May-11 »

He hasn't had much time lately, but the work continues. The front diff is fitted, plans of how the front suspension will look like is approved, and he's ready to start actually putting things together!
We will keep you posted!