Front Splitter and sport V2 bumper carbon homemade build
 

I've seen that APR sells a basic splitter for the Z, but it only fits the Nismo front end. I have the second gen sport front end and a very large chassis mounted rear wing. I'm looking to balance the front end with a splitter and trying to determine best options for fitment.

Has anyone successfully used the second gen bumper with the APR splitter or some other splitter and track tested it? If the better option is to get the Nismo front end, is there an aero preference between the two gens. From what I have found by searching it appears a couple folks have used the first gen Nismo bumper and either filled the space in the middle or bent it to form so there's an air dam effect.


Update - 11/24/20: after looking at various pricey options and talking to Professional Awesome, my race mechanic, and a few others who know what they're doing with composites I decided to try my hand at making a splitter. I'm not new to working with carbon, but I've never built anything from the ground up like this with it.

Initially I intended to buy a splitter, but custom made stuff gets expensive fast and even basic plywood runs over 400$. I decided to first try finding my own marine plywood and cutting that to shape.

I found a local source of marine ply, but it's not high quality and bent on me while sitting on its side for one evening. I bought a bunch of nice hardware from professional awesome and planned to mount the plywood splitter with it. I still plan to use the plywood for a replica and core model, but I plan to use it to eyeball the hardware into spec.

I'll trace the bumper onto the plywood and measure out 4" from every vertical dam section, which means I will likely have to do the dam first.

The plywood will then mount to the car to test fit and get cut down to rough splitter shape.

Then the bumper goes on, then dam, and final jigsaw cut to ensure a clean and smooth finish to the facing edge. I'll also make note of any hardware holes, recess any necessary and retest fit. I'll also make note of the bumper lower side which will likely need a fence and dam extension, and plan accordingly.

Now comes the fun part... I can get polyisocyanurate foam from home depot for 12$ in a 1/2x4x8 sheet. Carbon composites sells fabrics, epoxies, and bagging kits which I'll buy to do 1.5gal epoxy, 5 yards of bagging kit material, and enough carbon fabric for 2 layers, plus an additional carbon Kevlar layer (in red/black because why not throw some color in in life). I'll also get a resin tank and venturi vacuum generator from Amazon.

The foam will be cut to the splitter shape, the edges routed, the backing removed, any holes or cutouts recessed and cut, and then the whole thing will get a thin layer of resin to smooth and seal pockets in the foam.

I'll do the multiple layers of fabric with epoxy between each, bag the sandwich, and then let it cure for 24 hrs. Once cured, I'll sand it, clean it up, and give it a solid coat of a water based outdoor poly with my spray gun.

I'm at the measuring out the bumper step now :).

Update 12/7/20: there's an issue with the vacuum setup and carbon arrived!! post 32

I have the APR splitter on my V1 Nismo. I have a write up in my build thread. You have to use the ZSpeed undertray with it. I still have that gap in the center.

Check this one out.

https://www.battleaero.com/collectio...13934491140139

Yeah I read most of your write up, and that's where I saw the gap existed. It doesn't seem too terrible to cut up some abs plastic to shape and fit for an air dam.

Thanks for the battle aero link. I do have their swan neck rear wing, so the matching splitter might be nice. They're using a front lip as well though, and the sport bumper i think I'd have to just trim the bottom chin lip thing to act as an air dam?

Contact professional awesome racing.

I would recommend checking to see if you have a local plastic company. I found a company local to me that stocked up on their version of Alumalite (plastic composite mixed with aluminum). Charged me $80 for a giant sheet, good for 1 splitter.

Nine Lives Racing make one for the Z as well.

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Contacted them, and they said they would make a splitter (waiting on costs), but didn't say much about hardware, and that's the more challenging part anyway.

This is probably the best answer in combination with the battle aero hardware, so I don't have to develop my own, and forming my own air dam. I think the V1 Nismo bumper would probably serve the best aero purpose down the road, in combination with a small dam at the front of the lip lift.

Do you know what thickness the panel you got was and how much it weighed when you cut it to shape?

From looking at the V2 Nismo I can't tell if it has a flat bottom, nor how the air would actually travel on it, so it might be worse off than just the plain sport or V1 Nismo..?

Seems they want 485 for just the splitter, and it does look like a quality piece. They don't provide any hardware for that price though :(.

9LR makes quality stuff and is track proven! Personally I would use their products over BA because of that experience. Pretty much all the companies I am familiar with don't provide any mounting hardware because everyone has different needs. My first couple of splitters made by Next Level Performance and I had to cut it, drill holes and mounted it similar to what Rusty did. I believe Next LeveL still make their Nismo version one splitter. Also Carbon Signal makes a version one Nismo splitter.

Good luck in making your decision as there are numerous options including just getting one custome made.

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I don't mind doing some of the cutting, but if I can avoid having to make/weld my own hardware I'd like to try. 250$ for hardware to BA is steep, though. I was really trying to avoid having to shave the bottom of the sport gen 2 bumper and having to make an air dam, but it seems unavoidable unless moving to the nismo v1 bumper with a small dam at the front lip (or somehow bending it out).

If you not tracking the car the air dam ain't a big deal hell I hadn't worried about it because my talent wasn't up to all the mods I had anyway. I have been through three Nismo bumpers and on my fourth splitter. Them damn splitters tear chit up. Curbs are the devil and must be avoided at all cost!

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My car isn't street legal. No airbags, no interior, cage, track alignment, slicks, giant wing. It's a track only car and I can definitely tell when the front end is getting light while the rear is planted. My local track has a straight that has a small hill crest and kink about 80% of the way down. At 125mph and the rear wing dragging the car back (my gti could hit 131 mph at the same point), the front end gets pretty light and twitchy. The GTI was the opposite, the rear would get light and twitchy :rofl2: and that's a lot more sketchy since turn 1 is typically 75 mph +.

Right on! I am there with my Z as well. Aero balancing can be tricky. There is thread I started that speaks to some things to consider. I was mostly focused on spring rates for coil overs with a big wang and a 5" front front splitter. I haven't driven the Z in almost two years so it is going to be fun! Hopefully she will be track ready in the next couple of months.

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Just for reference I used this company that makes their splitters on order...(takes about 2-3 weeks) I have the stillen front fascia and my splitter fits perfect. They have splitters for several different aftermarket bumpers. Take a peek.


https://ventusautoworks.com/

This car is new to me, so a couple weekends ago was my first time in it, and my first time in an aero car on slicks on a road course. It was also my first time back in a Z and back in a 3 pedal car since early 2016. I have some relearning to do, and I have to move the fixed seat back (my elbow kept hitting the kidney seat ridge when trying to shift) before I get faster. It's setup as a TT3 car and I compared my times to the TT3 and TT2 drivers that were out that weekend. I was about 1.5 seconds ahead of the TT3 cars out and about 0.55 seconds behind the one TT2 car that was out. There are easily 2 seconds I'm leaving out on the track though, I know it!

It's so nice to be back in a Z! It really only took one session before the car started feeling very natural! :D

It doesn't appear they have a chassis mount option, and it looks like the "fang style" mounting option they have has an inappropriate angle to the ground. Maybe this design is more intended for a low speed/autocross situation with a higher rake setup?

How do you like the stillen fascia? Seems like it might be comparable to v1 nismo in terms of aero/ducting capability?

I like the Stillen... some people had issues with dimples showing in the front but I don't have those issues. I have some pix on in my albums. It's one of the best front bumpers for getting air into the engine compartment.

and you're right about the angle... Once I put the splitter on it points upwards appx 5-6 degrees so I need to level that off some. Also have the fangs with the front brake cooling kit too.

Yep, the splitter should be level or no more than 5* on a down angle. You be making lift which is no good! LOL

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:iagree: Yeah when I was over at Rusty's he broke out the digital level as he noticed it was off some. I'm planning over the winter time to get the full SPL kit and KW coilovers so once that's done and the car is lowered some I'll adjust accordingly. :tiphat:

So what are the two side vents for the stillen bumper feeding? I thought they were for brake ducts, but looking at the fang kit, it looks like the brake inlets fit into the main grill assembly?

It does look pretty mean though, and especially with the wrap color! I might try my hand at doing a wrap over the off season. Never done anything even close, but I'm not bad at painting, so hopefully some nuance and patience translates.

I think the Stillen bumper looks good. It reminds me of the Fugimura front bumper but not quite as sexy or as pricey. The reviews of the bumper is that fitment isn't always the best and can be a challenge and some have experienced a droop over time. The plus side is that it is one of the best bumpers for air flow and Stillen brake cooling kit works with it without any problems.

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Correct... the fang kit in the main grill has the 2" hose kit that runs to the back of the rotor. The 2 big openings on the side just feed more air behind the bumper that flows thru the engine compartment.

When I bought my car new back in March 2014 within the first 3 months I was driving on PA turnpike of all places and hit a deer which damaged my Nismo bumper. At that point I said to myself let the modding begin. :ughdance:

Had it now 6 years and not a single issue. I do see all the negative posts on the looks and fitment issues but have yet to experience any of that. :ugh2:

Is the bottom of that stillen bumper flat across and back? Meaning does a splitter fit flush against it if it was just a flat board?

I've seriously been considering buying honeycomb and 1/8" birch to make my own structure, but if alumilite is as cheap as some have come by that might be a better option. I am curious how much the racebred splitters weigh since they're a birch honeycomb.

Thanks for all the great options and suggestions everyone! This will be a fun off season project. Can't wait to get this car back out there next year!! :D.

Ps, if anyone lives near tulsa, ok, there's a mustang club event at hallett this weekend. I wanted to make it, but my wife has to work and that means I'm watching our baby :).

The splitter itself is semi rigid yet somewhat flexible. It's CNC machined aluminum composite. Here's a photo of the underside. The stillen bumper itself curves upward that small 5 degrees and this comforms to it nicely.

These guys over at Ventus Auto Works can do custom splitters or any variation you need as well. Not affiliated with them... just a one time customer helping out a forum member if you're interested.

This guy is an aero geek and freaking fast on the track. Here is his take on splitter materials.

https://youtu.be/LGCKGv2K4_M

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Hmm, I wonder how he feels about the wood honeycomb sandwich materials. Carbon is definitely the best if you go with a nomex sandwich. I've worked that stuff before and it's really easy. Problem is at splitter size the pricing is crazy. You can make your own 4x8 sheet of the stuff for around 600$, though, but you need a perfectly level surface.

I have not weighed the splitter I made. It actually wasn't even a splitter, it was just a chassis mounted undertray. Mainly made it for 2 reasons:

A: Test the chassis mounting
B: protect my oil pan and bumper from getting destroyed because I used to do street driving.

That being said, I street drive it maybe 2% of the time, very seldom. The race group/class I compete in restricts aftermarket aero, so I will be removing my chassis mount and maybe saving it for the future if I bump up a class. You may want to look into a racing league (ie. Gridlife, NASA, Global Time Attack) and build your car to a specific class spec (if you haven't already).

Regarding the chassis mounting hardware, I purchased the battle aero mounting brackets. They are OK but under heavy load, I do think the two mounting points are not enough and cause flex in the splitter. I would make 4 additional mounting points on a splitter with the Battle Aero chassis mounting hardware (2 in the middle, and 1 on each far side).

See image of their product: https://cdn.shopify.com/s/files/1/09...g?v=1571439730

So I'm talking to Professional Awesome about getting a custom cut piece from the racebred honeycomb birch and getting their mounting hardware since it's quick release (trailered everywhere). I'll have to do some fab work myself, but it shouldn't be too bad. Air dam will be fun...

I did the math on 10mm alumalite (which I read was recommended for splitter use over the 6mm due to flex) in the same square footage size as the birch splitter and there's a pretty massive weight advantage. 10 lbs vs 20 lbs. Carbon when done well is typically around 6lbs...so that's pretty solid.

So after more research on the racebred splitter, like most others it's a marine grade plywood that can be purchased in 4x8 sheets for 60-80$. This really doesn't seem worth it to me to spend 400$ plus 75 shipping on something I can make myself for <100$ and a couple hours of time. Granted, it's proving more difficult than I thought to find a source of marine grade birch ply.

I've been pricing out supplies to just make my own dry carbon splitter, and it's really not so bad. For that same 400$ I can get the majority of stuff I need and the work itself is pretty easy if you've ever worked with carbon or fiberglass before.

Anyone know of decent places to source marine grade ply, marine grade wood composites, or has anyone made their own carbon pieces?

Updated the OP... Looks like I'm going down the make your own dry carbon rabbit hole... I should be able to pop out splitters at 230-320$ consumables cost depending on carbon or Kevlar design, quality, and color.

In the past few weeks I made some time to order some carbon, do a good amount of reading on aero theories (I have a very good conceptual and practical understanding of physics in my educational background), and start putting a few things together.

Fun stuff first, I ordered all of the carbon and carbon Kevlar I plan to use for the splitter and it arrived very quickly! I also ordered some high temp and high impact epoxy resin with a 1 hour pot life. This is the same stuff that Boeing uses, and the same stuff some of the indy car builders use. It's only a 1 hr life so I will have to move very quickly, and it also requires a higher temp cure time. This resin is the only part I'm nervous about and resin is really the key to the whole thing! I bought a black commercial grade twil carbon since it was only 12$ per yard and weighs 203 grams per square meter. It will form the two base layers of structural carbon to my splitter. I also got the digital red camo carbon Kevlar, which is an absolutely beautiful product in person and really cannot be described or photographed well. It will form my top layer and should be the most durable. As I wear through it and black carbon is exposed I should be able to make repairs with my left over material!
https://live.staticflickr.com/65535/...7a180c37_k.jpg
https://live.staticflickr.com/65535/...7b52fe80_k.jpg

I got the bumper off and made a cardboard air dam to start. I'm still not 100% certain how to best cut an air dam to shape that will fit the curves of the front bumper, but I traced what I had to make a basic start and it's starting to resemble a splitter!
https://live.staticflickr.com/65535/...c5ffd7dc_k.jpg
https://live.staticflickr.com/65535/...95a913f7_k.jpg
https://live.staticflickr.com/65535/...a2b64069_k.jpg

Moving on, I got some hardware to mount up my professional awesome quick releases. It will be two u bolts per quick release with two angle brackets so that the u bolts clamp to the crash beam, the L brackets are bolted to the u bolts, and the quick releases then adjust up and down the L bracket as well as allowing the adjustment up and down the u bolt.
https://live.staticflickr.com/65535/...7b4612ad_k.jpg

If anyone else plans to jump down a similar rabbit hole, I highly recommend looking at professional awesome's diy front aero page, https://professionalawesome.com/diy-downforce/ . I did a tremendous amount of reading about a lot of other aero concepts after using their page as a starting point. There's really a lot to go down, but one of the key aspects which I didn't realize until I read about it, is that the Battle Aero wing that came with my car had endplates facing the wrong way :(. The meat of the plate should always be at the front of the wing. Also, the wing shape isn't ideal, but it's not bad. It's prone to a bit more drag than a typical wing used in motorsport with data behind it, and there's a lot of improvement to be had from going to a dual element air foil, so at some point I guess I might even try my hand at a carbon wing... Pictured below is the CORRECT orientation of the endplates. This should help reduce a tremendous amount of drag and improve downforce at the outsides of the wing. This is especially needed given the width of the Z's front and rear fenders which greatly disturb the air flow underneath the ends of the air foil.
https://live.staticflickr.com/65535/...5ae6ff0c_k.jpg

I measured out the radiator and the front grill intake as well. As it turns out the front grill intake (the functional parts not the plastic) are sized exactly 1/3rd of the surface area of the cooling stack! That's exactly how it should be! Who would have guessed nissan engineers knew what they were doing!? Now I just need to cut out the obstructive plastic and create a curved intake panel that will reach to the edges of the radiator to seal all that air in and force it through the cooling stack. With some louvres this should help keep all temps greatly in check and reduce underhood pressure at speed, which will lead to more downforce! I also plan to use the oem vertical DRL as an intake for the brake ducts. I checked and a shopvac general purpose suction end fits the size, so I may try to glue one on and see how it goes! Likely the intake will have to be downsized eventually, but that's not so hard to do...


So here's the major problem at the moment!! I bought a venturi vac to generate my vacuum suction for the resin catch which then sucks from the bag. I hooked everything up and I was missing several fittings. After a trip to home depot racing, I got all the fittings I needed and test the vac. It immediately pulled 27"hg but the cost was high... It needed a minimum 55 psi @ 3.5 cfm to maintain that vac and while my compressor can run 5cfm at 90psi, it only runs 3.5 cfm @ 165 psi and coincidentally that's where it got stuck on recharge and would run perpetually! It obviously would never get back to its 200psi full charge. There are other venturi that perform better and generate 1atm or 29"hg at only 0.5 cfm, but those cost as much as a knockoff vac pump on Amazon, so I went ahead and bought the vac pump. It should arrive this week for more testing!

Steep learning curve.

Keep in mind the suspension travel. You don't want the splitter to low to where it scraps all the time. I've hit a G out at speed and scrapped the whole bottom of the splitter.

Agreed, I did not have splitter supports and just lifting at 140 mph brought the splitter in contact with the road. Not good!

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Also, if you email those guys at Profesional Awesome Racing they may provide you with free advice. They have help me out a ton with my stuff.

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Yep, I've been working with them actually! They've given me some good advice so far and I have their front support hardware that has titanium pucks on the bottom to protect the splitter in certain impacts. I'll likely add a couple more titanium skids on the sides. They're not cheap at 30$ a pop, but not the worst either.

My measurements so far indicate I will be a bit over 3 inches from splitter to ground. The front springs are 14k and dampening is currently a bit on the soft end. I believe I'll have to up compression and rebound both a bit to account for the splitter but we'll see.

Did my images post for anyone else? I'm looking at my post now and don't see them at all...

Cool, the pictures did not post.

:iagree:

You have access to an autoclav big enough for a splitter?

You don't need an autoclave unless you're using an epoxy resin that requires high temp cure or you're trying to drastically accelerate your cure process. Prepreg also often requires a high temp or autoclave cure due to the nature of producing a carbon which contains a gelled resin.

The resin I chose is high impact and high temp (325*) with a 1 hour pot life and should take approximately 24 hrs to cure at room temp. The same epoxy can be cured for 18 hrs at room temp and 6 hrs at 185* to have a 450* temp resistance, but that also requires a different catalyst.

Edit: If you're referring to the use of "dry carbon" vs "wet carbon" in context, technically laying down your own resin layers is considered "wet" by the newer definitions but adding in the vacuum process and layering the resin/epoxy with a final higher cure temp also produces a "dry carbon". The goal is to get to 40% resin by weight to carbon and most well done vacuumed setups can get you pretty close. When I first worked with carbon in 2007 anything with resin content below 60% was considered "dry carbon".