Thread: SER RallyX Suspension Advise?

Also, was there any shifting of the top and bottom pieces of the arm at all? I can't recall if they're welded all the way along the seam or just spot welded between the plates. If they're not welded at the seam, stitch welding that might add some rigidity, but might actually make the stress riser at the end of the top plate worse. Hmm.

The arm that was bent did not have any stitch welds but the arm we replaced it with came stitch welded and felt a little heavier/beefier.

I'm sorry, I was going off of 100% memory of where the control arm bent. My memory isn't that great. I looked at it again yesterday and where I meant ball joint, I meant towards the thinnest part of the arm where the rearward mounting bushing is located. You can see it funnels down to a diameter maybe 1/2 that of the main part of the arm. I do believe the arm was stitch welded though, I'll have to get a picture of it for you guys.

Hey Lee,
Can you post the video of the hit as well?

http://www.partspile.com/rally/dcrallyxnov2010/ozrun1.wmv

yeah... light hit. Happens near or after :55 in the video.

Yeah, that hit should not have caused damage. What shape were the bushings in on the arm? Stock or poly?

I'm wondering if worn bushings allowed excessive movement and maybe increased the shock load or increased the leverage on the arm.

For that bend, I'm thinking a ~1" tube welded to cut the chord of the arm and triangulate the whole thing. Use the largest diameter that'll fit between the topa nd bottom plates, but stick with something like a 0.095 wall. Maybe a light sheet metal plate ont he bottom to keep stuff form getting lodged between the arm and the brace. I'd have to look to see if any of that would cause any interference issues in the range of travel of the arm. Sway bar perhaps, but that's not an issue if it's been removed.

I think triangulating the arm would actually help protect the front (weaker) mounting point too, by directing force to the larger rear mount and preventing twisting damage.

It was an aftermarket arm with relatively new rubber.

That was exactly what I was thinking in terms of a tube reinforcement. I also agree with you that the weaker mounting point is in the front. I feel that the way the control arm attaches to that point allows for the most leverage on that part of the subframe when horizontal force is applied. And that's no good for alignment or keeping your subframe/frame straight :P

Some fun reading:

Nissan Pulsar GTI-R Group-N Rally Manual at canadagtir.com

Of particular interest to this discussion is the following page:


The RNN14, is, at least in the front, largely similar to the B13. All NME (Nissan Motorsports Eurpoe, now defunct) indicates to do is to seam weld the arm and replace the bushings with stiffer ones (of note, they specifically say to NOT lubricate the rear, larger bushing).

The whole document is pretty cool though. Stuff like recommending replacing the engine mounts with poly, then drilling and tapping the mounts and inserting a bolt into the mount to assist in keeping the busing in place.

Also of note, NME spec'd 300lb springs in the front for gravel and 350lb for tarmac (however, progressive springs). Haven't found the rear rates yet.

Ooooh, score! Whole thing as a PDF. Guy says he can't host it for long though.

http://spd.blinkerfluid.org/nme/GTI-R%20NME%20Group-N%20Manual.pdf