posted on February 06, 2012 00:00
Project Nissan 350Z- Making the Chassis fully Adjustable and Getting Rid of Flex with SPL and Whiteline
By Mike Kojima
We had last left our Project 350Z with much improved braking at the track with a big brake kit and other parts from Stoptech. After her last on track foray at Buttonwillow, Sera reported to us that her 350Z was having trouble laying down power out of the turns. On the gas her car wanted to drift immediately which was limiting how hard she could apply the throttle on corner exit. The corner exit drift was not smooth but twitchy as well. When drifting with stock tires, her car was not so bad but with the forces generated by big sticky NT01’s the suspension’s bushings were getting overworked causing toe changes, hurting the car's stability.
| The first thing to do was to remove the rear crossmember.
With the sticky tires the car was also exhibiting a tendency to hop on corner exit, particularly on slower turns. None of this was particularly consistent so it was an annoyance that was contributing to slower lap times and made the car harder to drive.
There was also some vagueness of steering feel and understeer during turn in, although the car would feel OK in mid turn. Our mods so far had improved her car quite a bit, but she told us her daily driver 370Z still handled a little better.
|Howard Watanabe of Technosquare breaks the subframe bushings loose in a press.
To complete our suspension build, we had to make her car’s suspension fully adjustable so we could do a precision performance alignment to the chassis. We also had to get rid of the flex so the wheels would remain pointed in the direction intended even with the larger than intended loads generated by the sticky Nitto NT01 rubber.
|An airchisel is used to remove the bushings the rest of the way.
The first thing we did to accomplish these goals was to install some polyurethane bushings from Whiteline. We had looked at the underside of Sera’s car and saw that her rear subframe bushings were pretty shot from years of street and track driving and heavy loading from drifting. The deteriorated condition of the subframe bushings was allowing the subframe to shift around quite a bit. By witness marks, this looked like over ¼” at the bushings which could translate to over ½” of alignment change at the wheels due to the subframe bushings by themselves!
Read more about Project 350Z here!
Monday, February 06, 2012 12:06 AM
I need to do this stuff with my G35. Thinking of picking up a set of V3 KWs for it later in the year as well.
Monday, February 06, 2012 8:52 AM
Nice to see the 350Z getting some love. They're pretty nice cars for the money. I do have 2 questions: 1) Why is the manual alignment better than the laser alignment? I thought it was the other way around. 2) I'm planning to get some subframe bushings for my 240SX. It's not a DD, but it is a street car that I Auto-X and I may try some drifting in it later on. Should I get polyurethane, aluminum, or delrin? What are the pros and cons of each? Thanks.
Monday, February 06, 2012 9:57 AM
For a street car get urethane, for a race car get aluminum or delrin.
Monday, February 06, 2012 11:51 AM
I foresee Cosworth goodies on the way!
Monday, February 06, 2012 12:30 PM
Thanks Mike. I'm still curious as to why the manual alignment rack is more precise than the laser rack. Do most new alignment shops use them because they are quicker or what?
Monday, February 06, 2012 1:31 PM
I am not sure exactly why, perhaps beam diffusion or something but after using both a lot, I was really shocked to find out how inaccurate an alignment machine is compared to direct measurement.
We had a top of the line Hunter machine at work and the readings were off considerably from direct measurement even when set up very carefully.
I also did a R&R study of alignment machines when investigating tire wear issues as an engineer and was really surprised how far off they could be.
Monday, February 06, 2012 2:26 PM
While I do appreciate all of the project updates on this site, I'd really love it if you didn't let project Z32 die. Thank you.
Monday, February 06, 2012 3:41 PM
You guys are confusing the heck out of me.... please fix... for the rear suspension you guys replaced the camber arms... NOT TOE ARMS. Toe is adjusted using the eccentric bolts at the "Spring bucket". You used lock out bolts @ position you installed the SPL Camber arms. You should not have used lock out bolts @ the Spring bucket location because then you would have no control on TOE...The crazy SPL Mid-link can adjust toe without eccentric bolts.
I was going crazy rereading stuff about using eccentric bolts along with the arm to reduce further negative camber?! No way lol
Monday, February 06, 2012 4:22 PM
Yes way, what we did works, really well too.
Monday, February 06, 2012 4:53 PM
im not arguing what you did worked well or not. Im just telling you what yall did and what you documented are two different things and I hope you will do some research to edit what youve published for accuracy.
Monday, February 06, 2012 5:29 PM
I re-read it, are you talking about page 5?
We adjusted the camber and toe via the lower link and upper lateral link. We locked out the stock upper lateral link adjuster and used the adjuster in the SPL link.
Monday, February 06, 2012 5:36 PM
Page 5 and 6, basically anywhere you reference a toe arm. (I think you've confused yourself with which is the toe or camber arm.)
You installed camber arms. Camber arms from SPL have an angle to them. Toe arms don't. Review for yourself.
Monday, February 06, 2012 6:03 PM
In the case of converting to coilovers where we get rid of the stock lower arm with the spring bucket and replacing it with SPL's link you are correct, however we kept the stock spring location and the stock arm. So we adjusted mostly camber from the stock lower arm with the spring bucket and toe mostly with what SPL calls a camber link.
Monday, February 06, 2012 6:41 PM
I find it interesting that's the way you used those parts. Toe bolt to control camber, Camber arm to control toe...Figured it'd be more effective the other way around as that's how they were designed.
Wednesday, February 08, 2012 1:06 AM
With alignment machines, I bet they are highly sensitive to laser receiver sensor placement. I bet they don't get calibrated often. Imagine if the sensor gets nudged by a half degree or the laser gets knocked out a fraction of a degree well, there goes your alignment. Nothing beats a direct measurement!
Wednesday, February 08, 2012 2:27 PM
What about the newer style alignment machines that use IR cameras and targets that attach to the wheels with clamps? Do those have the same issues as the laser machines?
I wish Energy or Whiteline made front and rear subframe bushings for the 87-92 Supra (and steering rack bushings too for that matter). Those are the only bushings I need to finish up my car.
Sunday, February 12, 2012 11:35 AM
This build rocks! Next article needs to feature a video with some stunt driving antics by Sera!
Wednesday, February 15, 2012 3:19 PM
Hi Mike - Great write up! Would you mind providing a list of the SPL & Whiteline parts, including part numbers, you used in this article? Thanks in advance!
Tuesday, June 26, 2012 9:05 AM
Nice write-up! Thanks! It's great to see. Btw, on page 3 (2nd picture)there is a picture of the WL diff bushings mounted. Is there a reason why you put the thicker bushing on the top? The instructions from Whiteline and their bulletin show the thinner bushing on top. I just want to make sure that I install it correctly.
MotoIQ Proudly Presents Our Partners: