Stew24

Has anyone tried the EOS Diffuser Fins sold on Ebay and other sites? They appear to be knockoffs of the ACS Diffuser fins, with a slightly less sophisticated mounting setup. They are about 1/2 the cost of the ACS brand. The ACS versions are numbered, and you know which fin goes where, but the EOS that I bought simply have two that are #1 and two that are #2 stamped. The fins are not all the same length and have what appears a very slight bevel. Hand trial fitting makes it difficult to figure out which goes where?? There is an included drilling template, that shows where they should be, .. but not WHICH ones go where ? ...

2000 Vette Guy

Please post what you find out. I am interested in installing them on my coupe.

EMINENT 1

Lol @ using my car photo.

Hope it gets figured out. Maybe do some double sided tape and see how it looks first. Also, probably the ones labeled 1 are for the outer sides and 2 for the inner?

Avanti

Sometimes you get what you are willing to pay for...

Stew24

Hey dude, .. acscomposite.com ripped you off first! I lifted that pic from the ACS website. I also noticed the knockoff brands are using this same photo on Ebay. Trust me though, .. your badass Z is selling EVERY ONE of these that sell!!! ... Awesome View

KAIJU

Subbed. Interested in getting these fins but fitment is important .

JGarland

I have the ACS ones and i can tell you the inners are the same and the outers are the same.

I will check in the morning which ones are inner versus outer (longer or shorter).

The fitment is good enough but not perfect. There are some tiny gaps.

KAIJU

The fitment for the ACS one has gaps? I'd expect that one to have no gaps at all

JGarland

Very tiny gaps.

Imperceptible to most everyone except Corvette owners.

JGarland

The longer blades are inners.

Stew24

I didn't think I would be able to use mine on initial inspection. They have bevels to the mounting surfaces, which will cant the fins either one direction or the other. In other words, they will either lean to the left, or lean to the right? Also, I don't remember either of them being longer or shorter? I wrote EOS asking for some clarification on this, and they simply wrote back that they are all the same! Well, that's some BS, ... they are NOT all the same. After more inspection, it appears they are to be grouped together with both 1's on one side and both 2's on the other side. Which goes to driver's side or passenger's side to be determined.

JGarland

The ACS ones have a bevel/slant also.

Looking at your pics there....

I would say image #2 is for the LEFT SIDE

And image #3 is for the RIGHT SIDE

Those mounting surfaces are EXACTLY like the ACS ones.

8SPD Z51

Just installed a set of these...the ones marked No. 1 fit the passenger side, and No. 2 on driver's side.

KAIJU

Are these painter gloss black or carbon flash metallic?

8SPD Z51

The EOS diffusers come in gloss black. I used some GM black metallic spray paint on them, matches pretty good.

Stew24

I picked up an 8 oz. can of OEM Delco Carbon Flash Metallic paint in a rattle can for $18 on Ebay. Should be enough to easily spray the four fins.

Stew24

I would greatly appreciate seeing a pic of how yours came out? What are your overall thoughts?

8SPD Z51

I'll try and get some decent pics tomorrow. Unfortunately I just had by driveway resurfaced so I won't be able to get the car out of the garage for a couple of days.


I think the diffusers look great on the car. Installing by removing the lower fasteners and reaching up to attach the upper diffuser fasteners on the driver's side is a bit of a chore due to all the parts up in there. I ended up using hex headed fasteners rather the the supplied phillips head screws on the upper holes (so you can use a wrench).


Also, because you have to flex the panel to reach up, the holes need to be drilled a bit larger or slotted in order to get things lined up.
The fit is not 100% flush in a couple of spots but you'd have to get to within inches of the diffuser to notice.

If I were to do it again I would remove the lower bumper fascia and install the diffusers.

8SPD Z51

I forgot to mention....since I drilled the holes oversize I used washers on the back end with the fasterners.
Here's a few pics....not great but you'll get the idea.


Before anyone comments on the dirty pipes....haven't cleaned them since a got the car March, 2016. That's over 2 years and 20,000 miles of exhaust. Opted for that rather than painting them black.

KAIJU

Any chance they would stay on with 3M automotive tape or is that a no go?