Over the course of my ownership period of my 350Z Roadster I spent a good few pounds and hours on modifying it to erase some of the niggles it had as stock, and also to improve it as a drivers' tool. In the following thread I'll talk about what I chose, why I chose it and the actual difference it made to the car. I'll try and be as honest with my opinion as I can, but will try and keep the technical speak to a minimum so that everyone can understand it. I'm only going to focus on the performance side of the mods I did, as the aesthetic stuff is even more down to personal opinion. Again, long thread is long so grab that coffee or Red Bull now
Probably a good idea to start with exactly what I didn't like about the car really, which actually wasn't a whole lot. I did my research well when buying it and I knew what I wanted from the car and what I expected from it, which made the modification choice perhaps a bit easier than it might otherwise have been. Whilst the Zed ragtop is no doubt a fun car, it's also stupidly heavy (1780KG with a full tank and driver) and suffers a fair bit from losing the solid roof. The brakes are average at best and very poor when used on track, and the RE040 tyres it comes on just aren't good enough for a keen driver. That said, the balance of the car is wonderful and with the 296bhp engine there's plenty of revs to play with as well as low-down grunt, and that's a great start to work on.
BRAKES
As said, the stock brakes are a bit poor. They're probably fine for the people that treat their Zed as something to look good in, or as an A to B car for work use, but as mine was purely a weekend car I rely heavily on having a decent setup that I can work with. My budget for brakes certainly didn't cover the thousands needed for a BBK, and tbh unless the car is spending a lot of time on track or is running serious power then a six-pot or bigger brake setup is a little over kill. My use demanded brakes that could cope with 3-4 trackdays a year, and probably 10K miles of fast road driving without squeal or fade. The first thing to do was to add some braided hoses to improve the feel from the pedal as the stock rubber one expands under heat and heavy use, and having used Goodridge lines before that's where my money went. The feel wasn't as noticeable as I'd hoped if I'm honest, however I did this fairly early on in the car's life and so I think that after a few trackdays this would've really shown to be a worthwhile mod.
Another key point of heavy brake use is controlling the brake fluid temps, as when it gets too hot you can boil the fluid and be left with absolutely zero stopping power which clearly isn't an option, especially on track. At the same time as changing the brake lines, I changed the fluid to Motul RBF600 which has a far higher boiling point than Nissan OEM stuff. This gave a noticeable difference when under heavy and repeated braking, and yet I still wasn't entirely happy with it. The RBF600 seems to work better on lighter cars (I'd previously used it on my MR2 and VXR220) but the weight of the Zed was working against it, so I searched out the best stuff you can get and ended up with the Endless RF-650. This is about as good as you can get full stop, and is used in both current F1 cars and the 911 Cup race cars, so if it was good enough for them then it was good enough for me! Once I tried this I decided that I'll never use anything else again, it's completely brilliant and practically boil-proof. Then again, at about £150 for the brake system on the 350Z it wanted to be.
Once the basics were done, it was time to look at pad and disc upgrades. I started off by using the stock discs but with the Performance Friction Carbon Metallic pads all round, which were recommended to me by Big Phil at ESR as the best pads you could get with no exceptions. Again, not a cheap upgrade but even at £400 for the set it proved to be a great addition as both stopping power and fade were greatly reduced, and far more than I'd hoped for truth be told. There was no squealing that you can get with high-spec pads, and initial bite from cold was still very good: One application and you were there. That said, I still wasn't satisfied and went looking for something a bit extra as the pads were starting to eat the discs noticeable, and seeing as how I'd already got the PF pads I went for their front discs as well. Not only were they great to look at, but there was a massive reduction in stopping distance over prolonged track use and it really gives you the confidence to brake as late as possible. Maybe it's a tad overbraked for normal road use, but for any kind of track work these were an absolute godsend. £550 from Zmanalex, and probably as good a brake setup as you'll get without spending the daft money I spoke about at the top. Even friends who were driving 800kg cars with 260bhp were astounded by just how sharply my car would pull up when you jumped on the brakes.
CHASSIS/SUSPENSION
As much as Nissan tried to engineer it out, if you cut the roof off a car it is going to flex more on the chassis regardless of how much bracing you put on it. You can, however, get a fair bit more out than Nissan did...
I'd seen a bracing kit for the Zed when at JAE back in 2008 and was quite taken with it, but no-one could tell me if it fitted the Roadster. Luckily a set came up for a price I couldn't resist and so I took a chance and bought a complete 4-piece Summit Underbody Bracing Kit. You had one bar that connected the two front suspension points, two for the rear to sit fore and aft of the driveshafts, and one massive cross brace for the centre of the car to reduce flex there. I fitted the kit in stages to test what each different bit would do to the car which proved to be a great choice. First to be fitted was the front brace, which essentially mimics what the strut brace in the engine bay does by almost completely removing any movement from the front end at all under cornering. As such, what it gave the car was a massive increase in pointability, and instead of the steering feeling a bit numb I was getting a massive amount of feedback which in turn gives you the confidence to push on a bit more. Understeer was increased but that's to be expected really.
The two rear braces went on next, and that soon killed any understeer I had induced from the front brace addition. The best way I can describe the difference the rear braces made is to liken the car to a 911 in that you could get on the power ridiculously early, and it felt like you had a huge lump of weight pressing down on the rear giving you the extra traction. Suddenly I had a car that was both pointy but also neutral with plenty of power oversteer if I wanted it, and far more progressive than stock. Trouble was, the car still flexed in the middle until I fitted that massive cross brace I spoke about earlier...
A pain to fit? Yeah, it was, but that's because the forward holes don't have a thread in them in the chassis so you have to use these arms with a nut attached to them (very hard to describe!), however a bit of fiddling and they were in. It was as if someone had given me a brand new car again, but one with a fully welded chassis such was the difference. No more scuttle shake, no more wobbling, and the gains I'd gotten from the front and rear braces were magnified again as they were no longer taking up any of the slack left in the chassis. Even the guys at Abbey commented on how solid the car felt with them on, and they've driven enough Zeds to know what they're talking about. I still can't believe that the Summit kit is such a rare modification for people to do, as really it should be the very first thing to go on the car IMHO.
Around mid-way through my ownership I grounded the car quite badly on some country lanes and knocked the alignment out quite badly, way beyond what the OEM suspension adjustment could sort out so I purchased a pair of Cusco front A-arms and a pair of Eibach adjustable camber arms. With stock settings there is no difference between these and the OEM ones, and if anything these add a little weight! However, they do allow you to run some incredibly aggressive settings with regards to toe and camber, and I was able to get a very good setting between fast road and pure track that allowed me to maximise my grip out of corners, albeit at the expense of tyre wear. DMS are the guys to see for a quality alignment in this department, Dixon tailored the car to exactly what I wanted.
WHEELS/TYRES
I've never seen the point of buying a performance car and then putting rubbish tyres on it, usually accompanied by some power upgrades, as all you do is blunt the performance of the car at the one point where you will get the most from it, which is where rubber meets tarmac. If all you ever do to a car is fit some decent tyres, you'll be massively quicker round a track than someone who's got an extra 10% power increase on his car. It really is that important.
When I killed off the RE040s that came with the car, I decided early on to settle for nothing less than the best, regardless of cost. I didn't want to go for trackday specials (like the R888s) quite yet as I felt there was a better compromise to be had, and after speaking to a couple of people on here who had similar budgets for tyres as myself I went for the Michelin Pilot Sport 2s. At over £1000 fitted they were not cheap, and yet within a few hundred miles it was easy to see that they were worth that cost. Dry grip was insane, getting as close to trackday special rubber as you could reasonably expect, but the real difference was in the wet. They simply refused to aquaplane full stop, and even at track speeds in over an inch of standing water they were still giving me grip above and beyond what would be considered sensible! As if that wasn't enough, and sometimes outright grip isn't always enough, they gave me feedback that was as if they were sat next to me in the car telling me what the road conditions were like. "Careful Dan, this corner's got a hidden dip in it" or "The inside line is a bit slippy, go wider by six inches" I could almost hear them whisper to me. Slightly weird hallucinations aside, there simply is no better tyre for the Zed as far as I'm concerned. The RE050As do come very close, and might have a bit more grip, but they don't have the feedback the Michelins do.
With track use comes track tyres, and also track wheels. I kept my eyes out for a set of 18" OEM wheels which I intended to drop some R888s on and use purely for track. They looked as ugly as sin on the car, but that was irrelevant really as it was only for the track. The one downside is the extra weight the OEMs carry over the Rays wheels, and as much as I thought it wouldn't make that much difference it really did. Acceleration was terribly blunted by the heavy wheels, and the turn in was also numbed and so I sold them on, and purchased a second set of Rays at a higher cost. I quickly sought a set of R888s to go on them (in 225/40 and 245/40 sizes) and set about making mincemeat of other cars. The guy I run a race MR2 with currently owns my old VXR220 and so I know just how good a driver he is, and even in his car with all the ability both he and the Elise chassis have I was leaving him for dead on roundabouts. He was on A039s which aren't crappy tyres either, but they still couldn't match what the Zed was doing. When on these tyres the car became even more of a laugh, as a car weighing that much has no right to corner as fast as it could. It was absolutely hysterically good fun! Interestingly, I had absolutely no issues running on those size tyres at all even with the TCS on: No sudden power kills, or the rear stepping out unexpectedly. Sure, the speedo was out by about 5mph but that's hardly a show stopper.
And at that point, I made the decision to sell the car. I did put some Eibach ARBs front and back along with adjustable droplinks which I was hoping would give me much less roll in the corners but without having to change the suspension completely for something more extreme as I liked the way the stock springs and shocks rode. I believe that that's what I got, however they were only on for a few hundred miles and as such I didn't really get a chance to experience them properly so it would be a bit unfair to give them a full comparison. As you can see, I didn't bother ever chasing any power increases at all as chasing NA power gains gets very expensive very quickly with little returns, albeit I probably would've gone to see Abbey at some point for a reflash to smooth the power curve out. I feel that the car has enough power for what it is, and by getting the basics right you can end up with a car that is far quicker than one running big power. The only time I've longed for more power was on the Nurburgring, as that's where you really need it. On UK tracks and roads, 300bhp is ample and your gains come from elsewhere.
As always, I'm sure that others will disagree with how I went about things and would argue that power is everything, and yet by following the oft-quoted but rarely-used saying "First make it stop, then make it corner, then make it go!" I ended up with a car that would embarrass cars both bigger and smaller in the corners where it counts. Any fool can build a car for power if you've got enough cash, but I found that putting together the appropriate and complementing parts to make it as nimble as possible was a far more rewarding experience for me.
