To splitter or not to splitter, that is my question

CF736

Asking for advice on spitters from the track community. I have a 2017 370z base model coupe. I bought the base model specifically so i could later pick and choose the upgrades I want as I go in my effort to make the car track ready. I want to start by going to some advanced driving schools like they host at Buttonwillow and eventually work my way to doing some track day events.

So I really like the way front splitters with braces look on the Z but I do not know if it will be beneficial for track driving. I know a lot of people swap the front plastic over to a Nismo front end but I don't really want to go that route.

I like the look of the front splitter and would rather go that route IF it is beneficial or at least not causing negative aero issues.

With that in mind, could I please get some input from the track guys??

echoshotz

Yes, they're functional (theres a reason almost every TT/TA/real race car has them!) and theres definitely a benefit from from them. Being a new driver will you actually be noticing a difference over starting out without one? Probably not. Its more something you'd notice after you've found the limits of the car over several events. But with that being said, they are pretty cool looking and if you want one I say go for it

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BGTV8

^ what he says ..........

Even a basic lip will help

Check the splitter on my race car ........ and the lip on my Z34

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derraj06

A properly mounted splitter will definitely help. You may have to balance it with a rear wing depending on design. I see you're in Cali, hit up Corner3Motorsports. They run the Nissan Challenge track day stuff out there and build many a Z car for HPDE and competition and are always willing to share advice.

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MaysEffect

What tires are you using.

cv129

Believe his car is bone stock other than cosmetic things. He just got the car.

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Setrab | RE-71 | SPL | JRZ | Nismo | ARK | Whiteline | RacingBrake | CJM Oil Pan | Ti shield

MaysEffect

What tires do you plan on using...

CF736

Yes.. my car is stock right now. I'm just in the beginning phases of getting it ready for some advanced driving schools and such.

The tires are Yokohama Advan sports that came with the car. I'm still looking at wheels right now. I use the car at times for daily driver type stuff and would like to get a set of wheels that will fit some Michelin Pilot Sport run-flats for my daily use and then use the stock rims for some track tires. Michelin doesn't seem to make a run flat that will fit the stock base model 18" rims with the stock sidewall height.

MaysEffect

Alright then...With that bit of info out of the way. I recommend you holding off on duct tape splitters unless you absolutely need it for cosmetic purposes and get a good set of summer tires and brake pads.

YES, a well designed splitter (not a difficult task) will grant you a extra bit of handling feedback. But its a waste if you don't have a set of tires that will net you actual lateral grip.

The basic gains from any functional splitter design is to reduce turbulent drag on the front tires. IF you've ever driven a really high riding truck or a car missing the front bumper altogether, you'll realize just how bad this drag is on the tires. That small percentage of air that still makes its way under the front bumper and on to the tires is still a large amount but not enough to warrant wasting money on some stick on chin guard.

Next would be to make additional downforce and further decrease pressure under the car. This is where diffusers comes into play. These pieces of kit aren't cheap, and if they are, they probably aren't worth doodoo. Going back to point one. IF you don't have the proper tires to deal with this extra bit of force, then again it's a waste of money.

Ultimately -
You'll probably net the same amount of drag reduction by simply lowering your car a inch over some off the shelf splitter. So you can spend 200+ dollars on a splitter, or the same amount on a spring kit that may or may not be more functional overall (i say may because not all spring kits are made equal).

But before all else.

Tires is priority. Staying with the same diameter tires is also not a issue. You have a very broad clearance window of 25-27" overall rolling diameter depending on the width.

If you are using stock wheels. I'm assuming, front or rear, you are still smaller than a 18x10 wheel. So you can fit any tire up to a 285/35 comfortably (if you have at least a 9.5" wheel). IF your car has the smallest wheels, i'd move away from the large tires anyways and change to a 225/45 - 255/40 at the very least. This may look weird given the massive wheel arches, but the tire selections and handling characteristics would is much improved.

Lastly, Michelin PSS tires are a waste of money, they are old stock and still cost too much compared to the competition. You have several other options that will perform better. Why do you need run-flats? That's an additional cost that ultimately is not necessary unless you plan on going off roading. Tirerack offers road hazard protection for probably the same amount of money you'd spend on a set of run-flats compared to a non-RF tire.

CF736

Thank you for the time you took to reply. That was a lot of really good info for me. I do realize that I have a long way to go to get even a good entry level track setup, even for just an advanced driving school. The reason I was asking about the splitter is that I like the way they look and it would be a nice cosmetic change as well to get the Z to not look so "stock". I don't want to waste money on things that really won't be helpful though. If I can get a splitter or lip for $300-400 and it will eventually be beneficial to my setup then I may do it just for the looks at this point.

Regarding my desire for run flats.... I would like to get run flats just for my daily driving so I don't have to carry and/or have to use the donut tire that they call a spare. With a run flat, I feel I'd have a better chance of getting to a tire shop or at least to a safer stopping area or possibly even home without have to try to change a tire on the freeway or on some two lane rural road.


Thank you again for your feedback. I am really new to this stuff and so much appreciate the feedback I am receiving. I did try to research the splitter on my own but couldn't really find specific threads regarding them.

Rusty

If you are just getting into trackdays. Aero is one of the last things you do. Take that money and get some face time behind the windshield. If you are getting the splitter for looks. Knock your socks off. There are others things that you could do to improve the Z for the track. Once you start down the rabbit hole of trackdays. It gets deep really quick. So plan your mods to your skill level. It will save your wallet and your sanity.

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AlWakRa

This and good set of brake pads, brake duct, and tires (summer tires at least). Also, since you have base, should save for the Akebono upgrade.

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240se

What would be a good tire choice for a car that will be daily driven that won't heat cycle to death after a few months?

cv129

Not that PSS isn't a good tire, Mayseffect was pointing out that PSS has been replaced by PS4S, but PSS is still priced as if it is the latest model (same thing for those PS2, still carries outrageous price tags)

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MaysEffect

100%^

There are several good selections that i can't really list them all. The continental extreme sport is high on the list. The PS4S being arguably the best money can buy, although the highest price in its class. I personally don't buy in to this logic. I'm currently on PZ4's on my G and Dunlops sport maxx gt's (most underrated tire in history) on my FX.

Even if the Michelin's are statistically better than the competition, they are not worth the significant cost difference IMO. For the price i'd rather go with Extreme tires which i know work better on the street and track.

My Direzza ZII's worked better in all conditions over the PSS and lasted the same amount of time with the small caveat that it made slightly more noise and vibrated at high speeds toward the very end of its life.

The Nitto INVO IMO is still one of the best tires for its intended use, certainly for the cost. For the street, this tire handles perfectly with great comfort, even in low profile sizes. They don't have the most grip in dry/wet conditions but give a ton of feedback and are very smooth.