Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - This is the roll center, suspension pickup, and steering angle modification thread.

- Tech Talk (#/f/forumdisplay.php?f=8)

Quote:

Originally Posted by Tulok (Post 6408445)

You were right on both points. I actually had 1.5* of caster On one side I couldn?t believe my eyes. I did not notice that the tension rod had unscrewed itself most of the way within minutes of doing some practice drifts due to the wheel rubbing on it. The other side was not great either.

I dialed it back as far as I could to 6*, and added a larger spacer so I?m at -32 effective. And adjusted the coilover lower mount to reduce camber. And installed s13 lower control arms which are about 7mm shorter. So I?m sitting at about -4 front camber.

I have the Gktech v2 lower adapter on the low Ackerman setting.

It feels very good now, it?s easy to control the line and the front end has a lot of bite when I?m aggressive and it?s easy to widen the line and float out.

It feels a lot more like when it was stock just with a ton of angle, and more bite Which is great.

Good to hear!

Okay so these RLCA brackets were interesting. I think it's partly because I have wisefab, and partly just the way this goes, but be prepared to do a lot of fitting and triple checking. Also don't be like me and weld the inside seems without checking clearance first, I had to do quite a bit of grinding to get the heim joint spacers to fit back in :facepalm:.

https://i.imgur.com/KUMVKM7h.jpg

In order to get the rod end to not be maxed out, I twisted the bracket quite a bit. This helped a ton, and allowed me to not have to hammer the LCA or bolts into place, hah. I did also have to grind down the "seam" on the subframe pretty heavily to allow me to slide the bolt in easily.

https://i.imgur.com/l18CCJmh.jpg

https://i.imgur.com/N81DzSrh.jpg

Click for articulation video:
https://imgur.com/ICrxKoe

Wisefab with dropped front pickup:

https://i.imgur.com/b9DAAfyh.jpg

Fitment should be pretty nice, even with these second hand G35 wheels and maybe a few mm spacer.

Aren't the wisefab knuckles designed with different geometry? Isn't lowering that pickup point going to ruin the built in geometry of the knuckle?

Quote:

Originally Posted by TheRealSy90 (Post 6408940)

Aren't the wisefab knuckles designed with different geometry? Isn't lowering that pickup point going to ruin the built in geometry of the knuckle?

Wisefab was built around the S14/15 subframe and adapted to the S13. The S13 has too much anti-squat with wisefab. Watch Matt Coffman?s car move backwards on the e-brake and you can tell.

Got the subframe and Wisefab in the car. Really looking forward to testing this out. I modified this subframe by welding in my own steel 'bushings' aka two giant washers and a short length of pipe. It doesn't give the most absolute amount of roll center correction possible but I wasn't too concerned with that. Wisefab is still a PITA to install compared to individual arms, but a little less so now that I made sure everything fit before welding up the reinforcement brackets, haha. Eccentrics have also been deleted.

https://i.imgur.com/6ecUa1Ih.jpg

https://i.imgur.com/xhxp9nah.jpg

This is factory S13 control arms with the factory lock stop and Geomaster V3s on a 17x7 G35 wheel with a 15mm spacer. Unfortunately the trailing wheel still hits the front of the LCA, but I think with tires the tire will hit the tension rod before this happens. An aftermarket tubular control arm would fix this. I'll have to make a small lock stop to try and limit the arm for now, as I imagine the 17x8s I'll be running will make this worse.

https://i.imgur.com/zaZN65Wh.jpg

Just installed a full Gktech knuckle and suspension arm package, with the anti squat kit, on my s13. I also got new fortune 510s customized for longer stroke.

The first test drive was pretty darn good. The car feels different from every other S/A31- chassis I've driven so far.

Hoping to get more test drives in by next week, and I'll also try checking the bump & toe curves front and rear.

https://i.imgur.com/1VK4loXl.jpg
https://i.imgur.com/2l0MMYul.jpg

Seems like my 510s are most live-able at 1 click on the dampers.

As for the toe/ camber curves, it seems like the fronts gain negative camber and toe in as the suspension compresses. The rear seems to have toe in and a positive camber gain (??) under compression. I was just using a level app on my phone to measure the rear camber; unsure if it was just inaccurate if my car actually gains positive camber when it squats

I was able to do a track day with the initial setup. Based on the tire wear (in the rear), I have a bit of negative camber gain. Im wondering if i should play around with the traction rod to keep the rear more consistent at ~0 camber through the compression stroke.

With a completely stock SR20DET, blow-by, and 0.7-0.9 Bar, the car was one of the faster cars I've ever driven sideways. I could only compare it to my 230whp 1uz corolla running the same gktech antisquat kit (albeit with driftworks knuckles vs the S13's Gktech)