Hello everyone,

I recently posted some photos of my APR Performance splitter and people kept bringing up the angle of it. Rather than continuing and flooding the posts at "Your Vehicles As They Sit Now" thread I thought it would be appropriate to post it here. I was simply wondering if I'll see any negative effects or potential danger with how my splitter is currently mounted. At this point in time the splitter is connected with 10 bolts into the bumper, 2 splitter rods that are connected to the aluminum bash bar, and 4 perforated steel plates that connect to an aluminum under tray with self tapping screws (will replace with nutserts and loctite if I notice them pulling out). Using an app I found I measured the angle of the splitter and the angle of my driveway, which resulted in the splitter angle measuring about 9 degrees up off parallel with the ground.

People were posting how with it being at that angle it would be creating more lift rather than downforce. However, while driving on the freeway, 75-80mph, it feels like it's creating downforce and has better grip. Though I don't have any actual data to support this claim or know enough about aerodynamics to back it up either. I also figured it wouldn't be the biggest of issues since other splitter, Rocket Bunny for example, has the front end curling up.

At this time I don't plan on tracking the car, so I'm not looking for it to be perfectly aerodynamic. I'm mainly concerned with it having negative effects or being a safety issue. So all feedback is greatly appreciated.

Thank you, and here's a few photos of what it looks like mounted to the car.

 

The first thing you need to do is read the article that Peter (pyshin) linked. It will explain the "above and below splitter flow dynamics" that you need to know to determine aerodynamic effectivenness.

From this, you'll see why a splitter at freeway speeds really doesn't do a dang thing and may even be detrimental to normal operation due to the increased drag and high pressure build up underneath the vehicle. PARTICULARLY in the configuration yours is set at.

Also what needs to be considered in ANY aerodynamic improvement device is the BALANCE between front and rear aero. Any "improvements" to the front (or rear) of the vehicle have to work with the opposite end for their to be any reason to run aero devices to begin with unless just for looks/aesthetics.

And that's an OK reason to run same but just be prepared for possible negative side effects coming from an imbalance between front and rear aero.

Bottom line: If you're going to make your car slippery in the wind, do it with front, rear, top, bottom, and sides in mind or don't bother.

 

Oh my goodness. Sorry to break your heart, because I know you put some work into that thing, but not only isn't it helping (it's hurting, in fact) your Z's performance, it just looks ridiculous. Let this be one of those "live and learn" experiences, and pull that thing off.

 

I know when I was first looking at splitter on my car I looked at APR. after researching a bit I realized that all they provide is the flat section and you have to do additional custom work for it to properly fit/work.

You need to do some work and get it level

 

^^^ This is who I was hoping would chime in when first responding to you, DA.

 

Okay I'll see what I can do to make it level. Thank you for your input.

 

glad to hear that others chimed in, good luck.

 

Mine has a filler panel made to bridge the gap

 

May I ask why you have put it on ?

 

Well I decided I'm going to go ahead and trim my bumper to make it sit parallel. I also hope to make a trip over to Home Depot later today to get some longer steel plates and some angle pieces to help support the splitter.

As for why I got it. I created my own aftermarket webstore and APR Performance is one of the companies we sell, so I get a good deal on their products. Plus since we're selling their products I wanted to make sure that they're quality, which from everything I've seen so far it seems like they are.

 

Why are your splitter rods mounted so far in? Look at all the other rods attached in the forums and you'll see them attached to bumpers and such. You change that one thing and you'll be able to get the right angle on it.

 

I don't want the rods attached to the bumper because I don't want to put that much stress purely on the bumper. So the rods are attached to the crash bar using the existing holes. I need to get longer rods though because they're about as extended as far as they'll go. Though I think I also need to changed where they attach to the splitter. From what I've been reading they should be closer to the leading edge of the splitter.

 

Ah I see.
But it wasn't for any particular reason for track work or something like that I take it.
As MicVelo said, it's more likely that it'll be causing detrimental affects on the car unfortunately.

This is interesting to watch, and a great channel anyway: