Sup everybody Sooo , I have the sport bumper found on the 11+ S coupes. The only splitter for this bumper is one by stillen, but apparently it doesn't even fit the 13, 1) , 2) I don't even think the curvature follows the contour of the bumper that well and 3) It's over $300. So that one is out. I was thinking about getting a universal one off ebay but problems 1) and 2) are still there.

So after much deliberation, due to me not having much fabrication experience whatsoever, I've decided I'm going to try and make my own. The only reason I'm trying to do this is because I realized, how hard could it be? It's literally just a sheet of plastic/fiberglass cut to the proper shape and size of the bumper.

So for those of you have done this kind of stuff before, I have a few questions.

1) Which material should I actually use? I see that Stillen says theirs are made out of Polyurethane whereas outcast garage makes theirs out of fiberglass. Was also thinking out plain old ABS.

2) Which tool do you think would be best to give me the cleanest straightest cut? A jigsaw, compact circular saw, or a small dremel cutting saw?

3) I think it would be cool to flare the two ends up. How do I do this? Is there a material that is best suited for bending?

And with that said, I open the floor to any comments or pieces of advice

 

If its just for looks ABS will work fine. Its easy to source, easy to cut, and not very expensive if you dont like it. A dremel can cut fine if you have steady hands. If your cuts arent perfect just leave some extra material and finish the edge with sandpaper on a block of wood. If you want to flare the ends you'll need heat.

 

can't find any ABS sheet online... most plasce they charge an arm and leg for shipping..

 

So would there be benefits of using a different material?

 

I didn't plan on getting it online. I was just gonna go to home depot or lowes haha.

 

Well, the point of a real splitter is to be part of a cars air flow management system. To do this it needs to both be rigid, and capable of acting directly on the chassis. Typically composites are used and the whole setup mounts to the front frame/unibody structure. Plenty of budget racers have been known to use plywood as well, sometimes with a composite skin. Custom making something like this isnt terribly difficult if you are properly inclined.

For the record though, if you put it on your G, it needs to look nice. If its going on your track **** miata, then whatever. I guess I'm saying if you are new to custom fabrication, I would be very careful about homemade aero. Definitely easier to buy something professionally made.

 

For sure. But despite my lack of experience, I really think I can do this. Doesn't seem hard at all. What's proving to be more difficult than I thought is finding where to buy large sheets of ABS or Polyurethane. I'm not quite sure home depot or lowes has it.

 

Get HDPE if you can, at least 1/8" thick, if not thicker.

 

Yeah, you'll almost certainly have to order it online unless theres a distributor close by. Sheets that big are not common consumer items.

 

Nice to receive helpful input from you this time

But how come? Because PE is more flexible than ABS? As I'm lowering my car, will PE hold up better to scraping and accidental parking curb collisions?

And do you think 1/8" will cut it? The universal ones on ebay are all 0.5" thick.

 

To be functional, it should extend back to the front axle line and bolt to the chassis.

I have to question why one would want it functional; the RWD models are tail-happy and need more help in the rear.

 

Well that's good, because I have no intentions of doing that haha

 

I'm using aluminum composite for my rear diffuser which is reasonably rigid while still being fairly lightweight. A lot of people use alumalite, but I couldn't find any in my price range online. You might want to check a local sign shop because that's what it's commonly used for. Plywood is lightweight and also dirt cheap, so easily replaceable. A lot of track guys use this. ABS plastic is cheap and easy to work with, but lacking in rigidity. Not great for functional aero in my opinion.

As someone already mentioned, the splitter should be mounted to the chasis. A functional splitter can undergo over 100lbs of force so mounting it securely and to the chassis will prevent flex and increase the load on the wheels. I think a splitter will work well on our cars when used in conjuction with a rear diffuser and/or fuctional spoiler.

 

I don't really think I care for it to be functional. I don't track my car and I take corners like crazy on the street. Even if I did, I haven't even done things like coils/ strut bar, and sway bars yet, which would make way more of a difference in handling than this. Lastly, I definitely wouldn't see myself looking forward to having to detach the splitter from the chassis every time I need to take the bumper off.

 

EDIT: deleted original

This is what you want:

alumalite and alumacor @ 10mm (3/8)

Need something about 6ft long

Site (Stupid expensive):
https://harborsales.net/Home/Product...arch=alumalite

Next day shipping.

Or you can ask around for it at home depot in those specs or sign shops at a much cheaper price.



pic for reference.

Now go do it and DIY post so I can determine if I like it