betamotorsports

iTrader: (1)

If you look at true splitters they are actually angled or radiused up a bit to pack more air under the car. That's counter-intuitive if you are thinking of a splitter as a spoiler. But, a true splitter works to channel and accelerate air under the car. The more air you can get under the car, in a controlled manner, and the faster you accelerate it, the more down force generated. That's assuming the splitter is as close to the ground as possible. A splitter that's over 3" above the ground isn't a splitter anymore, its a spoiler. In that case it should be kept level or pointing slightly down.

Still one of the best aero references on the net: http://www.mulsannescorner.com/

kart14

My 2 cents:

Just go with 1/2 ply painted black till you get the height etc right.

Weld 2 tabs on the subframe to mount the back of the splitter (buy a mig140 and learn how to weld, princess auto or canadian tire - it's pretty useful when messing with your z - welding is a skill so you need to know your limits - but after a few practice runs you should be able to weld some 1/8 plate to the front of the subframe )

Buy 1/4 treaded rod and run it down from the bumper behind the grill to the splitter. You can just see it if you look carefully in the attached photo. I used 4, 2 you can see.

I don't like the supports that run outside the grill.

My setup holds me standing on it. With the downforce spread over the entire surface it doesn't flex or droop at speeds over 200kph.

The aluminum on the front is a little ghetto and I've messed with it a few times to fill the gap. I can clean it up with a single strip but it works for now. A V2 bumper likely won't need this treatment unless you drop the splitter lower.

Total cost about $75. Weight about 15lbs.

Good luck.
Matt

Fixxxercask

iTrader: (21)

Hey OP, I have made two different home made splitters for my car. As someone else on here said, they had to lower it to clear the sway bar. Originally I wanted to mate it to the bottom of the bumper, but I found that to be too high because it hit the sway bar. I have the OEM bumper and it is not perfectly flat on the bottom so there were gaps on both sides , therefore defeating the purpose of the splitter. I had to lower mine which created a gap between the bumper and the splitter so I ended up making an air dam too.

I made some brackets out of that garage door tracting stuff you can get from the hardware store and mounted them to the backside of the crash bar. They went down from there to the splitter and attached using "L" brackets. I also used all thread screwed into the bottom of the core support and down to the splitter. Then in the front I have four more pieces of all thread that go into a ball joint rod end. Those attach to brackets mounted to the front of the splitter and the crash bar.

I got a lot of parts for this from this place:
http://www.mcmaster.com/#rod-ends/=k9vbq9

Here are some pics of mine when I was making it. It is off the car right now and I will be putting it back on soon. I will get some more pics of the way its mounted when I put it back on. Also, it is strong enough to stand on.

KingBaby

iTrader: (3)

Authentic Nismo V3
ZSpeed undershroud

$950 plus shipping and handling



Other platforms are not as aerodynamic as the Z hence all the work around to get 'aero'!

In for the finish of this project nonetheless...

2TH PWR

iTrader: (21)

Well this has nothing to do with saving money. It has to do with strength and potential for making downforce.

The set up you talk about looks the same, but there is no way it can take your full weight standing on it.

mw9

iTrader: (51)

could not agree more, there will be hundreds of pounds of down force on the front splitter, if you cant stand on this thing, I would pass

just my 2 cents

betamotorsports

iTrader: (1)

Well.... generally no if the splitter is working as a splitter. The down force load from a properly designed splitter is carried by the body of the car (same is true for a rear diffuser). If the splitter is really a spoiler then you can see that kind of load on the exposed front edge.

Remember, down force generated under the car creates a pressure load on the top of the car body, not on the panels underneath the car.

Voboy

iTrader: (58)

Nismo V3 front bumper only generates just 11 lbs of downforce @ 73mph....

2TH PWR

iTrader: (21)

I forgot to add some of those posts were super helpful.

I am still hoping someone can post pics of the posterior support. But the welding on of tabs sounds like a great idea I never thought of.

Can you post more pics of this?

And the sway bar. How much would you recommend I clear it by in it's static position to be safe?

Are ou guys able to load up onto a trailer with the splitter on? Or do you attach it at the track everytime? I'm betting on the second option.

KingBaby

iTrader: (3)

How much would a splitter provide at the same speed?

Not trying to be the devil's advocate towards DIY. I'm all about DIY, just want to know more about how a splitter will provide more downforce than a Nismo v3 bumper.

2TH PWR

iTrader: (21)

Hard to say because those of us who make them don't have wind tunnels and scales.

But I saw a picture of GT-Rob on a track and he had a splitter made of 1/2" thick oak plywood, wrapped in Carbon Fibre and he hadn't quite ironed out the side support yet.

The oak plywood was warping downward on the side.

That takes a lot of weight. A lot!

03threefiftyz

iTrader: (25)

What is your source for this? I had seen 32lb at 73mph.

2TH PWR

iTrader: (21)

GT-Rob Hmm what do you guys think, does the splitter need some side reinforcement?






On the plus side I know its working, as to make it flex that much takes about 100lbs on the side. And those pics were only top of 3rd gear!

Z_enthusiast

iTrader: (16)

Im am curious also as to y everyone is saying it will have a heavy load if the wind is suppose to go under the car as you said.... Are we making a cheap lip spoiler or a splitter???

KingBaby

iTrader: (3)

I'm no astronaut, but the only thing I see from those pics are a incomplete design. Nothing against it but more supporting rods to bear the load.

2TH PWR

iTrader: (21)

This. The car is rapidly compressing air infront of it. Compressed air tries to move. It moves from an area of high pressure to an area of low pressure. by impeding the air flow in a downward direction, and by chanelling air in a more straight direct path under the car, downforce is made. I don't know how to make it more clear.

Compressed air is basically ramming down onto a shelf from top to bottom.

It is more complex than this. But this will give you the idea people are going for.

2TH PWR

iTrader: (21)

Check post 31 -> 33 -> then here
It is simply an example of the types of force generated.
Try and bend plywood like that.

KingBaby

iTrader: (3)

This I know, my question above is how is the lip on the nismo v3 not doing the same?

2TH PWR

iTrader: (21)

Its not to say they aren't doing the same thing on a physical level and I'm sure a lot of the same physical principles are at play.

But it's

vs


or


vs


Same principles applied. Different construction. Different outcomes.

KingBaby

iTrader: (3)

lmao

I like the picture reference

and

Rather see you car look like the rx7



I always thought what Zspeed did was genius. If I had the resouces which I don't it takes months to rise a v3 wing here on island ...

I would lengthen the mustache piece/apr splitter, and mount it below the bumper. Adding 6 turnbuckles 3 on each side of fascia...

in for more