Track Build Feedback -- lets build a (semi)racecar!

fairladyATX

I've been tracking the Z on and off for the past 2 years and it's time for her to transition to a dedicated track car (while still staying street-legal and driveable for occasional trips).

The goal is to have a reliable, fun, and safe HPDE car.

It's already partially there, but after driving home from the track a few weeks ago the air compressor seized up and broke the serpentine belt. I took this as a sign she wants to be more track-oriented.

I want to prioritize buying/installing in this order:

Safety
Suspension
Diff
Transmission
Engine
Aero
(Braking is already done and I like the setup)

My goal is to "finish" the build for ~$10k, and it looks doable if source used parts where it makes sense (like suspension), and do DIY installs where I can vs. pay a local specialized mechanic (like Austin Z Clinic).

At this stage -- I'm mainly curious if I'm missing anything major or overlooking anything minor.

And since the car has just hit 80k miles (and WITHOUT any major issues--all engine and drivetrain parts are mostly original) I'm wondering if I should start replacing water pumps, oil pumps, PS pumps, etc. pre-emptively, or let those ride.

In the Notion doc, it breaks down what's already installed vs. what I think I need to buy to round it out.

Any feedback, tips, or concerns on what I have here so far would be greatly appreciated!

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"Casual" track car...NASA TX.

2011 Nismo#91

Wow! Someone made a good post, goals check, budget check, put effort in before asking for advice check. Thank you!

I'll do my best to give you all the info but it's going to take awhile. But just form your post I know your going to have a good track car.

OK so goes! This is based on the assumption that 98% track car 2% street car that will be driven to the track and not towed.

SAFETY Stick with reputable brands! Seats Preferable a halo seat and fixed back if you can manage it. Avoiding seat sliders can give you a little extra head clearance. Try looking for a place you can try them out. Harness 5 or 6 point and make sure to install it correctly. I have seen many people not allowed to track because they had the wrong angle or distance. Cage TBH you can just get a quality harness bar. MA-Motorsports for example. I used "RPM Roll bars" 4 point cage. But you'd have to check if they still make on otherwise you'll just have to get one made by a shop others have used at your track events. I would not recommend any other prefab cage. A simple extinguisher bottle mounted in front of the bottom of the seat or behind you, just keep it within reach with a harness on. It's very very unlikely but also pretty cheap if something catches fire and you can't get out first. ALWAYS AND ONLY GET OUT OF A CAR ON TRACK IF IT'S ON FIRE AND GET BEHIND THE WALL!* Also if you haven't already invest in fire rated gloves, shoes, and undergarments at a minimum.

Suspension, All good, I'll link my track/street settings.

Manifold, Not really necessary, but if you can sure, why not. Oil Cooler, Your probably going to need BIGGER. Minimum 34 row! If you can try adding some ducting to air is forced to flow through it rather then find a way around it. Engine Mounts, Good, not sure how much they are really needed. You really need a fuel starve fix system! CJM is the best but $ and isn't always available.

Exhaust, up to you but see if you want to get simple cutouts manual or electric, might save you some money and keep the exhaust stock.

Rotors, Personally I don't care for 2 piece, especially Z1's crap steel, "Warping included at no extra cost." Cryo treated blanks have worked just fine for me. Pads, Might be too aggressive XP12 but that's up to you. Most use 10's. Street Pads, I'd keep with the same brand/comp Carbotech Street pads. There are some recommendations to rebed your brakes every time you switch. Check the brake fluid every few sessions if it gets even a little bit low from pad wear you'll get an "Brake" light on the dash.

IMO go with the Whiteline bushing. OEM Clutch/Flywheel will last reasonably well. But since you should be upgrading the CSC you should do this too. Any flywheel will chatter so just go with a lightweight one. Stay away from a puck and dual clutch ones, more than you need, full face organic will do just fine. Zspeed CSC delete or HDCSC is needed. The heat will just destroy the stock one.

Wheels/tires
I'd be looking at DOT tires or slicks. These on your stock sport wheels and DOT/Slicks on the aftermarket. Wheels switch to 18" square if your investing in wheels. It will save money and offer a larger selection. I'd go with a tried and true Enkei Racing RPF if you must. IMO sticking with stock wheels a little longer will save you some initial budget.

Aero
Undershroud isn't really needed unless your OEM one is damaged. If you can get the get the Zspeed undershroud. Hood vents, Very helpful! Kinda scary making that first cut. Splitter, Only helpful at the advanced level, more trouble than it's worth. A proper sized one will need to be removed when not at the track or it's a trailer only car. Wing Only helpful at the advanced level. Plus if you want a functional one, your going to have to get one of the big obnoxious ones. If your going all out trailer track car make a proper diffuser.

Other
Tow hook, OEM works great and is functional. Many aftermarket ones are more show then functional. Paint the OEM one if you are really concerned about the look of it. Anyway it's a race track Function>Looks! Oil Pressure gauge, Important! Why are you replacing the stock sensors, the gauges should come with a sensor? Water temp gauge nice to have but not too necessary. I never overheated NA but the stock gauge is useless. The pod is very nice to have! I like mine.

The AC doesn't rob power like in the olden days. It has a clutch that only engages when you turn it on. When it's off its just the resistance of the bearings. Honestly is a few pounds of weight worth having to sweat in the texas heat? If your concerned about weight, relocate and switch your battery out to a lithium one. If you are determined to get rid of the AC a cool suit is a good investment.
Not sure what pulleys you'd remove, I don't see a worthwhile cost benefit there. It's not worth the headache.
Oil catch cans get them sooner than later, not having it may cause throttle body issues later. Baffled oil pan is a worthwhile investment the CJM one is a work of art. Unless you're razing the RPM limit, which you really shouldn't, you do need an oil pump upgrade. Pumps, Hoses and subframe collars are nice to do but not necessary or needed unless there is a problem.

Yaw Sensor kill switch. Ok but ask yourself before you turn it off, "Is it OK if I crash today for that extra 2 seconds because I need that trophy to get sponsorships?" If it's yes then sure go right ahead. You are much more likely to be towing your car home and cost a lot more than that switch. I almost never turned the TCS off, was I slower for it, sure. But I am also fairly certain I would have crashed at least twice. In non competitive driving there is really no incentive to get those extra few seconds except for a little online bragging.

Tools & Misc, Pyrometer for more data for logging. Brake fluid Tester so your not changing fluid needlessly. Portable air compressor powered from your car. Outlets and on site air sometimes are not available. Corner balance your car. I never did, but I always did my best time with a passenger as ballast :P
I'm sure you have the other basics down already.
If I didn't mention anything on your list specifically then it's good.

Notes on Safety
*Any reputable organization will have an emergency vehicle that is much better and properly equipped at putting out fires then you and that little bottle can do. It's only purpose is to give you a little more time for them to get to you and extract you from the burning car.
If you are getting a harness you NEED to get a HANS device and have the helmet that works with it.

Airbags, this is a tricky one for a track&street car. It's simple if its one or the other. On the one hand airbags don't really provide much benefit on the track if you have a helmet, hans, harness, halo seats, etc. On the street it's not practical to drive like that and probably more dangerous. Unless your lucky and can get a set of OEM seats (Juke NISMO) with harness holes and make your own for the 5th/6th harness point your going to lose your side airbags and weight sensor which kinda sucks for the street. AIRBag360 can help with the weight sensor loss. But your airbags (up to 3) will now deploy for the passenger regardless if a person is there or not, $$$. I would not recommend driving on the street without a steering wheel airbag. Your 3 point belt will not stop your face from inserting itself into the steering wheel without it.
IMO keep as much of your safety systems intact for the street and simply pull the airbag fuse when you get to the track. But the real answer is don't touch any of it or make it a dedicated tow to the track car. I could go on for hours but I think this is more than enough for now.

This is what I use, simple cheap and works. Your standard ABC is fine just messy, there are clean agent ones but ask a professional if you should use them in the cabin of a car with you in it.
UFEB1317/D Car Fire Extinguisher Bracket — The Bracketeer

http://www.the370z.com/members/2011-...03-14-2018.jpg

My track record times I think are pretty respectable, all with full TCS on and a passenger. "It's not a matter of if you crash, it's a matter of when" "The best trophy is taking your car home in one piece"

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GTR TT 493Whp/431lbft, Ecutek, Southbend 6puck,Quaife, RPM RollBar 4Point, R888R, JRZ RSPro F(10R/10C) R(10R/6C) 1000f500r inlbs+150inlbs Tender, SPL everywhere.Full Specs

filip00

I'll just chime in with a few, since I don't have much experience with the Z mods, but I'll add what I can:

EDIT - I only just saw your full list on the link. Nice work, you are a very good planner.

1. Safety being seats, seatbelts and fire extinguishers? Guessing here. If so, I'd go for bucket seats which suit you, 4 point harnesses, and a fire extinguisher you can fit in front of the driver's seat.

2. Suspension - there are endless options, probably coilovers are best choice. Not sure which tho.

3. Diff - OS Giken for the win. Costs but I can't think of a better option.

fairladyATX

Dude this is awesome, thanks for your input! I added some notes/context on a few things to see if that changes your advice for me.

Interesting -- I ruled out just going with a harness bar since they *can* be more dangerous in event of a rollover. My (limited) research had me land on a 4-point weld in cage.

I saw RPM is popular but at $2,000+ price point, while some of the others are $500. Not sure if "you get what you pay for" applies a lot here since the design looked very similar but I didn't inspect weld quality or type of steel, thickness, etc.

Awesome -- this would be super helpful as a starting point. I'm installing the KW coilovers and SPL parts this weekend.

I haven't experienced any fuel starvation issues yet at 4 different tracks I've been on -- but imagine it's bound to happen at some point. Didn't consider it originally since it's a non-issue. I don't let the tank go below 1/2 full, so maybe that's why?

I have an Invidia Gemini installed right now with Berk HFCs, stock headers. I don't *need* any more power mods, but the more torque = the more smiles. Same reason why I was looking at ported intake manis.

I've been using XP10s front / XP8's rear and they've been great. Was going to bump to 12's front, but going to hold off on trying that until I get a sticker compound tire (in the future).

So far the Z1's 2-piece has been good, although I see the XP10's aren't wearing evenly after the last track weekend so I'm trying to figure out what is going on there. The pad thickness is different at the ends.

Regardless -- agreed that blanks generally are the best route (sans going to a big break kit). Might go back to blanks after this Z1 set is worn out.

Plan is to change out everything at once, and probably before there is a failure. 80,000 miles and ~1,000 track miles on the stock trans so I imagine I'm inching closer every weekend to a CSC or clutch failure.


I killed the OEM undershroud going off track last year. And with the oil cooler, lines are running below so I like the added peace of mind that they have some more protection. I've been able to stay below 240-250 deg wit the 25 row, but I think you're right and I'll upgrade to the 34. Hood vents are already in and I think do make a difference.

Wings, splitters, and canards....just because they're cool and I've wanted a winged car since I was a kid. Extra down force is just a bonus. Racecars are toys, so might as well have fun with it!

My AC died after the last track weekend. Drove home, white smoke started coming out of the hood vents and the AC died. Drove 4 hours, stopped in my driveway, and the belt snapped. AC compressor seized up. The local auto shop said there was metal that went through the entire system and damaged everything and wanted $4k to replace everything. I said no thanks, I'll just bypass the AC, and that's what started this journey to make it more track-oriented.

I imagine the compressor wasn't designed to operate at high heat/high RPMs consistently (even if the AC is off).

Yesterday I removed 2 pulleys and got a new belt to bypass the compressor. Car is back running like a champ. I'll take out the compressor another day and if I ever need to replace the radiator I can get one without a condenser.

I bought the Z because it's modern-ish but basic. 6MT, all motor, minimal nannies. It's a "drivers car" compared to many other modern sport cars that can do most of the driving for you. I'm faster with TCS off, and like the challenge of being able to drive it without the assist. I haven't turned VSC off yet but if I can get back on track with no/low other traffic, I'll see how it feels without. Last weekend I was 2 seconds faster without TCS and less frustrated by the killing of power in corners where I wanted it.


Well said. Always am proud when me AND the car come home in 1 piece.

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"Casual" track car...NASA TX.

fairladyATX

I was split between OSG and Wavetrac and ultimately decided to go for Wavetrac since the common consensus is it does NOT need a diff cooler.

I just want something better than the stock vlsd and that seemed like the most cost effective route to go.

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"Casual" track car...NASA TX.