Sunny N14 - Suspension development
Hi,
As you may have noticed... I trackday my Nissan Sunny N14. The Sunny is the same plattform as the NX2000 or Pulsar.
During this season we improved my suspension setup a fair bit. And I want to share a few 'unconventional' things we did!
First of all I tried to align the car with the basic stuff and a set of coilovers and top hats installed.
I got a really decent setup with arround 3 deg of camber in front and 1.5 in the rear. But I knew there was more, the car felt good, but there was more...
I asked Mike K. over facebook to give me a few ideas on the setup he used on his cars. And I realized really fast, that the car needed more caster!
You have way to little caster. I would run a minimum of 4 degrees. I would prefer around 5. I would run a higher rate rear spring, about 500-600 in/lb. I would run a bigger tire like a 225/45-15 and run more negative camber and, as much as 4 degrees and slightly lower air pressure.
My caster at this time was around 1.5 degress! I have eccentric bolts in the knuckle, So i can dial in or out some camber over the bolts there!
So we started with new sturt tops. They are 45 degress rotatet, with these I can dial in some more camber and castor together!
Further I wanted more camber to get it in a range above 3 degrees - which was not possible with my old setup, and would not be better with the new top hats.
I did research on the interweb and orderd a few different parts from Nissan - we realized that the Nissan N15 lower arms are the same as the N14 ones, but each is around 15mm longer!
Now things got really fancy! We got the N15 lower arms, replaced the bushings and fitted a Whiteline caster special one in it. The good thing about this modification is that I have now more camber, but what makes it even better is, that I can dial out some scrub on the front axle. The car should feel more stable and calm in the steering wheel!
As I knew the car was tooooooo low at the moment, and I calculated the front and rear roll center, I knew I had to fix this issue now! The front roll center was well under the ground, and the rear was ok. Surprisingly the rear roll center was in a really good position.
I had an idea, and i checked the internet and the local dealer again. The S14 ball joints had the same tapper! So I orderd a set of moonface S14 roll center adjusters - with this modification my rollcenter would rise a fair bit, as they offset the lowerarm by 15mm!
Here I installed them to the knuckle - to check if everything would work out! And it did... ... not. The housing has a diameter of 42mm whereas the lowerarms size is noticibly smaller! No problems for us, we just milled it down a little to make it fit and flush! Now it fits perfectly!
Here the comparison. old vs new
To finalize my setup I needed something to correct my bumpsteer issue. I orderd a set of Joe 2J-Racing bump steer correction parts...
--
For reasons unknown the 2J parts do not work with my front setup at the moment. I do not blame anyone, but I think this will need some time to work it out. The inner tie rods and the outer tie rods together are just to long....
I hope Joe and I will wind a solution for this issue!
Nevertheless - last sunnday I went testing the new setup with a new alignment on track. The car feels great, is very responsive, and very predictable. Right now I am really happy with it.
As we have engineering habits - it is a great progress with the new parts we made. But in my mind there is already more...
As you may have noticed... I trackday my Nissan Sunny N14. The Sunny is the same plattform as the NX2000 or Pulsar.
During this season we improved my suspension setup a fair bit. And I want to share a few 'unconventional' things we did!
First of all I tried to align the car with the basic stuff and a set of coilovers and top hats installed.
I got a really decent setup with arround 3 deg of camber in front and 1.5 in the rear. But I knew there was more, the car felt good, but there was more...
I asked Mike K. over facebook to give me a few ideas on the setup he used on his cars. And I realized really fast, that the car needed more caster!
You have way to little caster. I would run a minimum of 4 degrees. I would prefer around 5. I would run a higher rate rear spring, about 500-600 in/lb. I would run a bigger tire like a 225/45-15 and run more negative camber and, as much as 4 degrees and slightly lower air pressure.
My caster at this time was around 1.5 degress! I have eccentric bolts in the knuckle, So i can dial in or out some camber over the bolts there!
So we started with new sturt tops. They are 45 degress rotatet, with these I can dial in some more camber and castor together!
Further I wanted more camber to get it in a range above 3 degrees - which was not possible with my old setup, and would not be better with the new top hats.
I did research on the interweb and orderd a few different parts from Nissan - we realized that the Nissan N15 lower arms are the same as the N14 ones, but each is around 15mm longer!
Now things got really fancy! We got the N15 lower arms, replaced the bushings and fitted a Whiteline caster special one in it. The good thing about this modification is that I have now more camber, but what makes it even better is, that I can dial out some scrub on the front axle. The car should feel more stable and calm in the steering wheel!
As I knew the car was tooooooo low at the moment, and I calculated the front and rear roll center, I knew I had to fix this issue now! The front roll center was well under the ground, and the rear was ok. Surprisingly the rear roll center was in a really good position.
I had an idea, and i checked the internet and the local dealer again. The S14 ball joints had the same tapper! So I orderd a set of moonface S14 roll center adjusters - with this modification my rollcenter would rise a fair bit, as they offset the lowerarm by 15mm!
Here I installed them to the knuckle - to check if everything would work out! And it did... ... not. The housing has a diameter of 42mm whereas the lowerarms size is noticibly smaller! No problems for us, we just milled it down a little to make it fit and flush! Now it fits perfectly!
Here the comparison. old vs new
To finalize my setup I needed something to correct my bumpsteer issue. I orderd a set of Joe 2J-Racing bump steer correction parts...
--
For reasons unknown the 2J parts do not work with my front setup at the moment. I do not blame anyone, but I think this will need some time to work it out. The inner tie rods and the outer tie rods together are just to long....
I hope Joe and I will wind a solution for this issue!
Nevertheless - last sunnday I went testing the new setup with a new alignment on track. The car feels great, is very responsive, and very predictable. Right now I am really happy with it.
As we have engineering habits - it is a great progress with the new parts we made. But in my mind there is already more...