[Armand]

i just recieved my kansai carbon rear diffuser lastnight and had a quick flick through the instruction. now i get the general idea of installing it but do i HAVE to cut my rear bumper to install it?

coz its all in japanese and unfortunately i dont speak it
so its just abit of guess work by looking at the pictures.

i remember there was someone who posted a few pics of him installing it but i cant remember where the post is? tried searching but couldnt find it.

thanks

Armand

[turboranger]

i know kir diesel did a rear diffusser on his car but his was a Mature. you can check his journal if you wanna im sure youll see pics there of him slappin it on.

[toogood]

its bolt on...no cutting

[wdb]

Originally Posted by toogood

its bolt on...no cutting

I think you have that wrong. The HKS requires cutting:



The APR does not require cutting:

[fourseasonsandles]

Pretty sure you have to cut it. From DubyaSTI's Journal.... I want one!!

Cutting
DubyaSTi...6/11/08...Shifty knob and yellow lights

Finished product
DubyaSTi...6/11/08...Shifty knob and yellow lights

[toogood]

[quote=wdb;1631849]I think you have that wrong. The HKS requires cutting:


i apologize

[DubyaSTi]

I'm fresh off my Kansai install so I'll help out the best I can.

First off, the most important thing is to take your time. Test fit, test fit, test fit!! Also, I would put painters tape all over the bumper to prevent scratching when your test fitting.
Now, yes you have to cut the bumper, otherwise the diffuser will never fit.

I picked up a Dremel Two Speed rotary tool to do the job...it made cutting the bumper very clean and easy.
These aren't the best pics but it's all I have for now. It's hard to say exactly how much you have to take off...as a gauge I would say it's going to be from about the drivers side rubber exhaust hanger to the tow hook on the passenger side. Start off conservative and trim as necessary.



Now once you've cut away the bumper, you'll need a helping hand to find out where to drill for the mounting brackets. Take out your spare tire so you don't pierce it with your drill.
Mount the bracket to the diffuser. Now go under the car while you have someone hold the diffuser up to the bumper in the position that you want it to permanently sit. While you're under the car, push the bracket all the way up until it hits the spare tire well. Hold it in place and mark the spots for the 4 holes. Take the diffuser assembly out and drill you're 4 holes.

Next, go back under the car with the diffuser and bolt it into place. At this point, check your fitment with the diffuser on the bumper side. Once you make sure everything is flush, get a marker and mark the 6 holes that you will be drilling for the rivets.

Once you're pleased with the placement of the holes, let the diffuser down and drill holes for the rivets. The two holes closest to the license plate will require that you drill into the bumper beam behind the bumper, otherwise the rivet won't go in properly. BTW the rivet size you'll want is 3/16 dome with a 1/4 to 3/8 grip range.

Now take your rivets and test fit them in the diffuser and the bumper (basically so that the diffuser is now being temporarily held in place by both the rivets and the bracket). Once everything looks good, break out the rivet gun. My suggestion is to have a buddy hold the head of the rivet gun so that when the rivet finally snaps, you don't go and put a nice scratch in the diffuser or bumper (I came close).

Here is the end result...


Now every install will probably be different depending what muffler you have, but with my RS*R catback, I had to trim about 1/8th of an inch off of either side of the pre-existing muffler cutout.

This certainly isn't the hardest install in the world, you just need the right tools. Obviously, a rivet gun and some kind of rotary tool are vital to a proper installation. Like I said just take your time and check your fitment before you go drilling anything. Once you rivet this bad boy in, it would be a PITA to take off.

[Armand]

thanks pal!

tried to install it lastnight but didnt have a proper drill bit to drill the holes under the car. just about to start it now.
if i get it finished today i'll post some pics of it up later tonight.

thanks everyone for your help/advice!

Armand

[DubyaSTi]

No problem and good luck!

One more thing I forgot to mention...I would suggest using some kind of silicone on the bolts that go into the spare tire well, as to prevent any rusting.

[105sti]

I will be undertaking this tomorrow, just with the carbon fiber one ohhh joy...Mine came with bolts no rivets at least i didnt see any with my quick glance in the package. How wide of a cut is needed on the bumper, it looks to be almost 1 and half wide tape..How long did it take you from start to finish about 2-3 hours? Thanks for the help...

Chris

[amg destroyer]

Very good write-up. This has probably been covered before, but will this diffuser work with an angled exhaust?

[DubyaSTi]

Originally Posted by 105sti

I will be undertaking this tomorrow, just with the carbon fiber one ohhh joy...Mine came with bolts no rivets at least i didnt see any with my quick glance in the package. How wide of a cut is needed on the bumper, it looks to be almost 1 and half wide tape..How long did it take you from start to finish about 2-3 hours? Thanks for the help...

Chris

Mine didn't come with any bolts or rivets either, just the ones for the fins. I picked up some stainless steel bolts for all of the bracketry. As for rivets, I picked them up off ebay.
As for how wide it has to be, do you mean left or right or up and down? Left to right I can only say you should test fit the diffuser underneath the car. Hold it underneath the car, and mark where the left and right diffuser fins are going to sit. Basically, that's where you'll need to cut.
As for up and down, it was like 2-2.5 inches. Once you take the license plate off, I think I cut about 1/2" down from the indent of the area behind the license plate (you'll see what I mean when you take the plate off).

If I had to guess, with all of the running in and out of my house test fitting and trimming the diffuser, it took about 3 hours.

[DubyaSTi]

Originally Posted by amg destroyer

Very good write-up. This has probably been covered before, but will this diffuser work with an angled exhaust?

It will work, but you'll have to basically cut the diffuser into two pieces and make up a custom bracket for the drivers side of the diffuser.

[105sti]

^thanks for the help...will be starting it up here in a few minutes...

[propeller]

I have question, did you paint your diffuser and order the fins in CF? what is the original FRP color?