APR Performance Rear Diffuser Install w/ JDM Rear Aprons - Subaru WRX Forum
 
LinkBack Thread Tools Display Modes
post #1 of 6 Old 02-15-2009, 11:35 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
APR Performance Rear Diffuser Install w/ JDM Rear Aprons

This diffuser can be found on APR Performance's website below, and will fit WRX/STI's from 02-07.
APR Performance - Subaru Impreza WRX Rear Diffuser

This diffuser will fit MOST rear aprons/spats, including the 04 and 05 JDM rear apron with little or no additional modification. I am installing the FPR version on my 04 WRX with the 04 JDM rear apron, which is already installed. Although APR does include instructions with the packaging, it never hurts to go into more detail. I also found the photocopied pictures included were very difficult to see.

If anything is confusing or unclear, feel free to PM me, and I will try to explain it better and clarify it in this article.

Tools/Supplies Needed:

Metric Sockets, wrenches, and allen wrenches (hex keys).
Power Drill w/ drill bits
Dremel - optional
Misc hardware explained in the how-to
Tape


The diffuser is in two pieces with three adjustable mounting arms loosely bolted into place. Also included was a set of instructions, some brochures, and a package of hardware.
Name:  CIMG4278.JPG
Views: 9532
Size:  152.6 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae

Last edited by Vew; 04-21-2009 at 03:14 PM.
Vew is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 02-15-2009, 11:56 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
The first thing is to remove the rear recovery/tow hook. You will not put this back onto the car. If you wish to keep the recovery hook, you will have to drill a slot for it in the diffuser. I will be removing mine.

Three bolts hold it on. Two that mount straight up to the frame, and one more on the side. Although both ends are in a bolt shape pattern, only ONE is actually removable! The other is welded on. Don't do what I did and accidentally snap it off (on a previous mod). If you do, don't worry, it's not going back on the car. And if you're putting it back on you just need to replace it with a nut.

You will need a 17mm socket to remove the bolts.
Name:  CIMG4279.JPG
Views: 9175
Size:  103.2 KB

Once loosened, the brackets should slide off. You will not be using these anymore.

In the bag of hardware they've included, the larger pair of bolts, washers and nuts are the replacement. I ran into a problem when installing mine. I had to go to Lowes to buy a larger washer since the ones they've included are barely larger then the diameter of the bracket. I contacted APR about it, but they failed to get back to me.

Shown is what they included for this part, and the larger washer I had to buy.
Name:  CIMG4290.JPG
Views: 9089
Size:  67.1 KB

This is what it looks like after installing it properly.
Name:  CIMG4291.JPG
Views: 9120
Size:  108.2 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae

Last edited by Vew; 04-12-2009 at 08:46 PM.
Vew is offline  
post #3 of 6 Old 04-12-2009, 08:56 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
You now need to remove the pair of nuts/bolts on each apron.

Name:  CIMG4293.JPG
Views: 9138
Size:  94.2 KB

Name:  CIMG4295.JPG
Views: 8988
Size:  56.7 KB

Removed
Name:  CIMG4298.JPG
Views: 9486
Size:  89.2 KB

Now you should be able to slide the diffuser under the aprons. This isn't the easiest task since it puts a lot of stress on the 3M tape holding on the aprons. Mine ended up coming off partially. There is a problem though. You may be able to tell from the photos below, but because the diffuser does not conform to the shape of the bumper like the apron does, there is a point on the apron that pushes against the diffuser that makes it stick out unevenly. You can shave this off, or just live with it. If you leave it, it will more then likely scratch up the area that it contacts.

*** Update ****
If you do not shave it down, it will pull the 3m tape away from the edge of the bumper. It does not risk having it fall off or anything like that, but it will create an annoying gap between the bumper and skirt.
**************
Name:  CIMG4299.JPG
Views: 8983
Size:  59.5 KB

Name:  CIMG4302.JPG
Views: 11725
Size:  70.5 KB


Now you can line up the holes from the apron and diffuser and bolt them down. I opted not to use the ones I pulled off and used longer ones since it makes the task MUCH easier. I recommend picking up a hardware kit like this one I got form Advance Auto.
Name:  CIMG4300.JPG
Views: 8910
Size:  84.9 KB

Here's a better photo of the piece you probably want to shave down.
Name:  CIMG4301.JPG
Views: 8858
Size:  62.6 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae

Last edited by Vew; 12-18-2010 at 10:07 PM.
Vew is offline  
post #4 of 6 Old 04-12-2009, 09:15 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
Repeat to the otherside.

Now the task is to drill through the diffuser and bumper to make the diffuser sit flush to the edge of the bumper. Again, I didn't like the way APR wanted me to do this, so I came up with my own solution. The reason I didn't like they way APR's method is because although I can get about half the hardware in no problem, there are sections where I can not physically attach a bolt to the inside of the bumper since the diffuser is blocking the only access.


****
Just a quick update. I'm having problems keeping the screws in the bumper. I can only assume that the bracket is rusting and not holding the screws in place anymore. In any case, one winter will turn even coated screws brown. I would suggest stainless steel or use APRs hardware unless you do not mind changing them yearly.
****

Use a piece of tape to help hold up the diffuser.
Name:  CIMG4303.JPG
Views: 8880
Size:  76.6 KB

Here is the type of hardware I use. Self-tapping screws and clamps. You'll see why in the next few photos.
Name:  CIMG4304.JPG
Views: 8911
Size:  87.4 KB

Pre-drill the holes through the diffuser and bumper. Be sure you measure and check 3x before you start drilling!!
Name:  CIMG4305.JPG
Views: 9323
Size:  55.1 KB

After pre-drilling
Name:  CIMG4306.JPG
Views: 8819
Size:  58.9 KB

I used a Dremel with a bit attachment for the next part. You can use the drill to do it too.
Name:  CIMG4307.JPG
Views: 8872
Size:  93.4 KB

Name:  CIMG4308.JPG
Views: 8772
Size:  58.8 KB

Attach the clamp. No access to the back? No problem. Thanks goes to Chris, my co-worker for this solution. After you line the diffuser back up, the screws will go right in. Don't worry about how it looks. It will be covered up by the diffuser.
Name:  CIMG4309.JPG
Views: 8768
Size:  63.2 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae

Last edited by Vew; 12-18-2010 at 10:06 PM.
Vew is offline  
post #5 of 6 Old 04-12-2009, 09:27 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
Now to secure the back portion of the diffuser with the self adjusting arms that were attached to the diffuser. You need to drill through the fender well. I used a 13/64th bit. I also got some lock washers to ensure they won't vibrate off.

First, line it up and mark where you will drill. You can adjust the arms by twisting the center cylinder.
Name:  CIMG4312.JPG
Views: 8770
Size:  73.8 KB

After drilling
Name:  CIMG4313.JPG
Views: 8738
Size:  65.0 KB

Lock washers I used
Name:  CIMG4315.JPG
Views: 8727
Size:  88.7 KB

In and bolted down.
Name:  CIMG4316.JPG
Views: 8691
Size:  87.3 KB

You need to tighten down the part that allows you to adjust the length.
Name:  CIMG4317.JPG
Views: 8795
Size:  79.7 KB

Name:  CIMG4318.JPG
Views: 8696
Size:  79.5 KB

Same thing only though the spare tire well.
Name:  CIMG4319.JPG
Views: 8692
Size:  101.1 KB

Name:  CIMG4321.JPG
Views: 8599
Size:  58.1 KB

Final
Name:  CIMG4323.JPG
Views: 8608
Size:  92.2 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae
Vew is offline  
post #6 of 6 Old 04-21-2009, 03:14 PM Thread Starter
Vew
Moderator
 
Vew's Avatar
 
Join Date: Feb 2004
Location: West Virginia
Posts: 3,452
Images: 10
Vew is more helpful than not
Send a message via AIM to Vew
Final Install Photos.

Name:  CIMG4750.JPG
Views: 12344
Size:  106.5 KB

Name:  CIMG4751.JPG
Views: 11972
Size:  104.8 KB

Jon
"We live for a good time, not a long time."
RIP Colin McRae
Vew is offline  
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are Off
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On