Sway-bars, under-steer and over-steer

CMR 30mm rear Swaybar GTR
Well, I got some new parts over the last few weeks, so I've now updated my build story. I also did a small write up on Sway-bars for the GTR, and added it to the "how-to" guides on the right. I also managed to pick up a great new steering wheel!
Momo Champion Wheel


I feel as though I should mention that in the downloads section, we've got the 340 mb Holy Bible of how to assemble the Nissan Skyline, it's the one made by Nissan themselves, and used by the service technicians.

Leave some comments and let the authors know what you think of their stories!

Click "Read more" to see the updated portion of the build story:

New Year? New Parts!... January 10, 2011
After being prompted by several forum members to look into how sway-bars work a little more, I found out that its not advisable to change one sway-bar and not the other, unless you want to modify the over/under-steer characteristics.

So, Naturally most cars come from the factory setup to have a little bit of under-steer, thats because in a high speed turn, even an inexperienced driver can handle under-steer, but not everyone would be able to handle an over-steer situation, cause over-steer would send the tail out and spin the car.

Well, so too is the Nissan Skyline GTR setup to come with a little under-steer from the factory, and I haven't made this problem any better by fitting the 9" wide rims in front and the 9.5" in rear, more traction from the rear + it's a rear-wheel biased AWD system, its a recipe for a huge amount of under-steer! Which I noticed pretty quickly at the track, it made the car pretty safe to handle since I'm still a novice track-day goer.

so, by using bigger/smaller sway-bars in the front and rear, one can modify the over/under-steer. For example; If your car is under-steering, and you wanted to help balance it out you would fit a stiffer rear sway-bar, the stiffer rear end will cause the tail to slide out more, effectively correcting under-steer. 

So, when my car gets fitted with a stiffer front sway-bar, it would make it under-steer even worse! Not, what I needed at all, so I sent an email over to Adam in Japan and told him to find me a big after-market rear sway-bar, and a set of bushing kits for the end-links (mine are rather worn). He didn't fail me! CMR 30mm Rear Sway-bar with bushings and brackets, and a kit of pineapple bushes for the links.
CMR 30mm Rear Sway-bar GTR and pineapple link bushings
So to put the whole thing in perspective, I measured the OEM sway-bars, and compared them to my after-market ones, heres what I found:

  • OEM Front: 21 mm (Apparently hollow?)
  • OEM Rear: 26 mm (Solid as far as I can tell)
  • Cusco Front: 24 mm (Solid)
  • CMR Rear: 30 mm (Solid)
So my front would see an increase of 3 mm, while the rear would see 4 mm, I think this is enough of a difference now between front and rear stiffness that my under-steer problem will be much better.

Got a Handle on things... January 24, 2011
I've been putting of the interior of my car for a little, while working on performance stuff, so when I saw this pop up on the forum for sale section, I jumped on it.
Momo Champion Steering Wheel 352mm
Momo Champion Steering wheel, 352 mm, with suede on the top third, really happy with how it feels. I've already ordered up a steering boss adapter from Adam, should be here by the end of the week I'm told.