My history with this 2004 Nissan 350Z

I picked this car up on October 22 2013 with about 65,000 miles on it. It needed new brakes, new hatch struts, a new clutch and new tires. I ended up replacing that stuff and rebuilding the suspension of the car over several years while I figured out what I was really trying to do with cars, given the situation I was in at the time.

Starting in 2014, I began to do some track days and autocrosses with the car and found the car very predictable. However, it was clear some things were not quite right in the front suspension. The driver side lower transverse link had become detached from the inner pivot bushing, allowing the link to get pulled forward on its mount and introducing wear into the arm. My solution was to replace all of the serviceable front suspension pieces: balljoints, bushings, front upper control arms and lower transverse links. I chose Whiteline polyurethane bushings for the front as a compromise with spherical bearings and there are downsides, but they are not enough to change my mind on the choice.

In December 2019, I replaced the factory exhaust with an Invidia Gemini stainless steel cat-back unit. It’s slightly louder than stock and a true dual, so upgrading to full headers or forced induction in the future would be handled well. I also replaced the diff cover with a larger capacity unit, added a Bell Raceworks diff brace, some Z1 rear subframe bushing collars and most importantly, replaced the very broken diff bushing which is a trait of the platform. The differential and subframe pieces transformed the car; there is a slight increase in NVH, but the car is incredibly solid. This equates to significantly improved confidence on track and during autocrosses when you are transitioning rapidly. This has also contributed to significantly increased lateral traction at speed. Replacing the shocks with Koni Sports seemed to resolve the unstable feeling in the rear of the car on the straights at PIR.

At the end of May 2023, the Z is going in for another set of modifications:

These upgrades should keep the car cool during autocross and track use. The next things on the list are new tires and I am trying to figure out the best course of action. I really want to put 18x10.5 wheels on the car with either 285 or 295 width tires. I would prefer that those tires be R compound, but I’m wondering if I should start with something like an RT660 or RE-71RS before moving to the slick. This will be a large traction increase in the front of the car, as it is equipped with 255/40R18s now.

Update June 2023

So I wasn’t able to get the springs, coolers, rack, or headers installed in time, but a bunch of other stuff did get touched and resolved, as well as discovering that the LF brake line was being pinched and damaged by the swaybar walking towards the drivers side. I installed a pair of aluminum collars on the swaybar to help keep it from moving. I also fixed a several coolant leaks that I had not seen before but had definitely smelled, swapped a bunch of the factory hoses for silicone equivalents which included a metal bleed valve on the heater line. The oil pan spacer is in, the intake spacer is in, the injectors were swapped and the catch can is installed. There is currently some idle behavior which either means the computer needs to run through the relearn process for idle air or there is a vacuum leak somewhere. I’m going to investigate those shortly. Also, I realized that the front-end plastics attachment points were pretty beat up on the car. I’ve ordered new fasteners to rectify as much of that as possible.

Update September 2023

Q40 Motorsports held a dyno day on 09/02. Since I had swapped injectors on the Z, installed the Z1 Motorsports intake plenum spacer and the Invidia Gemini dual exhaust, I wanted to run the car on a dyno again and see how the AFR graph looked and see if I picked up any power. THe car did indeed pick up power, was not running lean and had a steady AFR graph compared to what it ran at PRE in 2019. I attribute that to the missing #1 cylinder, with the root cause being the #1 injector failing. With 108k miles on the car, it’s to be expected there’s going to be some fuel system issues.

The end result was an increase from 217HP maximum to 247HP maximum, and up from a maximum of 201lb-ft to 230lb-ft. Now, if you aren’t aware, no two dynos will be exactly the same, so I was more focused on the AFR graphs proving out that the fuel system is doing what it should be doing. The car is definitely more powerful according to the butt dyno, and as you can see from the Q40 dyno sheet, it’s a very flat torque curve with over 90% of the available torque from 1500RPM to 6000RPM.

I refuse to run the car on the track until the springs, rack and wheels are installed. That means the car will probably hibernate for the rest of the year in terms of events. I need a few days off and some rack time to do the spring swap, and since I’ll be in there, it makes sense to replace the leaking rack. To fit the 18x10.5 RPF1s and 285/30R18 RE71RS’s, the fenders will also need to be rolled. I’ll be installing camber lock outs out back as well, since it’s pretty obvious the OEM rear camber adjusters have slipped.

The car will be ready for next year, but I’ll probably be focusing on the Corvette from here on out, with the exception of the engine & power steering cooler installs on the Z. The Z is in a good place to be competitive with a competitive driver, whether that’s me, a friend, or a new owner.

Update October 2023

I took a few days off after my birthday to take the car into my friend Jeremy’s shop so I could get some additional work done on the car. My goal was to get the springs and oil coolers installed, but I only managed to get the springs and Z1 eccentric camber lockouts installed. I took the time to do a bit of an inspection on the car as well, checking over the work I had performed in May. Everything looked good - the oil pan is not leaking, the differential is still dry and no coolant or fuel leaks - all of which build up my confidence that the car is getting much closer to track ready in 2024.

I dropped the car off at AR Motorsports in Tigard for an alignment - trying for as much negative camber in the front as possible and one degree less in the rear than the front (-3F/-2R). During that process, one of the rear Z1 camber arms snapped. Word to the wise - if you drive your car on the street, putting a layer of anti-seize on exposed threads will help make adjustments in the future much easier.

The next step is installing the 18x10.5” RPF1s on the car and taking care of any interference issues. The car is definitely a bit lower with the Spec-R springs but there is quite a bit more negative camber in the front than before. This should help the cars mannerisms during autocross and track use. I’m still planning on using the Corvette as my autocross car, but it probably makes sense to have someone run the car on an AX course or three to help shake out any issues with it before taking it on a track.

I’m keeping an eye on sales for Race Louvers and 9 Lives Racing products, as I think downforce and cooling mods will be the next long term pieces to add to the Z, assuming it’s going to be focused on TT and HPDE only. I’ll probably be switching to either true-style coilovers or a custom rear spring bucket to eliminate the toe eccentrics in the rear, as well. The existing Z1 suspension parts will eventually be changed out to SPL.

Complete modification list for the 350Z:

Parts ready to install on the car:

  • ISR Performance ceramic coated long tube headers w/O2 extension pigtails
  • Lower plenum ready for porting
  • Remainder of Z1 Motorsports silicone hose kit
    • OEM Oil Cooler/Heater hoses
    • R&P hoses
  • Dark door handles in packaging

350Z on track with HOD

350Z on track with HOD

350Z on track with HOD

350Z on track with HOD

350Z on track with HOD

350Z in surgery

350Z in surgery

350Z underside shot

350Z in stationary action

350Z dyno sheet from PRE in December 2019

350Z dyno sheet from Q40 Motorsports dyno day in September 2023