I have a JDM rear and was going to build a diffuser to close up the parachute of an air scoop that I have going on in the back.
Would it be better to just cut the cover? That's kinda the impression I'm getting after reading up on the topic.
Seems that even if I close it off, I'm still getting a lot of messy air in the wheel wells, anyway, so may as well....?

Please don't do honda kid things to your evo. There will always be dirt air in the wheel wells. Build a diffuser or leave it alone.

Oh stop. Its a supped up cheap econo car. And there are plenty of fast "hondas" with honda boy things done to them. I bought a JDM 7 rear bumper which I will chop. There is a nice line on Evo 7 bumpers which makes it easy to chop. Credit goes to Ayoustin who gave me the idea and was planning something similar but I think he just chopped his USDM Evo 8 bumper.

Don't cut the bumper, that's never going to look normal. Styling doesn't matter if it was a honda or a subaru or some drift car but don't do it to your evo. The jdm rear hardly has a parachute, its more the usdm rear has that problem. If its a genuine jdm rear then you have the license plate cut out which allows most of the air to flow out of that area anyways. Otherwise make a bracket like this to close that gap or something similar:

The evo you posted is just...ew gross. Goes to show you can make anything look ugly. Also speak for your own car..I dont think the evo was ever supposed to be an econo car. Its anything but economical. As for cheap, try saying that to my wallet

Cut bumpers look terrible to me. And they don't do much for aero. You still need a diffuser.

There's no point in cutting the JDM bumper my friend. Unless you're going to cut the trunk pan too cause it's quite close to it and very close to the same height. If you want to leave the trunk pan in place then you will never really need to cut the bumper because you won't achieve an aggressive enough ramp angle on the diffuser without causing flow seperation. If you're causing flow seperation you might as well have done nothing to start with back there.

Here is an Apr diffuser on a usdm bumper to show you how limited an angle you can run anyways. No point shaving the 1" off the bottom of a JDM bumper for that last 0.3 degree.

Time attack cars are also hideous but designed for 100% function. Thats what we're talking about here. This is the motorsport forum after all.

Its based on a lancer for god sake. You must think the lancer or mirage is/was a beautiful car along that line of reasoning lol

The evo is no holds barred performance oriented. Looks were always an afterthought even in its production from day 1.

Its a niche look to owners who love them. But they are not beautiful cars by any stretch of the imagination. Its a 4 door car with a big trunk. The interior is hideous and cheap.

We're not talking about an Italian car here guys... Its mostly plastic. And OE USDM bumpers are a dime a dozen so why not chop them. The JDM 9 bumper has some money attached to it so I prob would not chop that.

Also seeing as Im permanently on 18" wheels and no longer can use or carry a spare tire, I'll be ditching the spare tire well anyway.

Bottom line is: I don't care what the car looks like, if I can do something to fix a problem (you should see my fender rolling job ).
however, if it's not going to help or at least not be worth the trouble, then that's fine too. It saves me from covering myself in plastic shavings.
P.s. My bumper cover has scuffs from a safety barrier and is trimmed, behind the tow hook cover, for my trailer hitch receiver. I don't think it's worth much any more.

Thats fair. But that other guy must think hes in the show and shine section of evom.

It was 35 grand NEW. Thats a cheap performance car. About as cheap as they come.

He thinks Evos will be worth $200k in the near future. I'm not paraphrasing.
At first I was like "WTF" but now I'm convinced it's a past member trolling again. Remember the "fuel pressure" guy?

To be fair, $35k in 2006 is approx $45k today. Not too cheap, but definitely not bad, for its performance

Its ironic because the only thing that gives these cars value in peoples eyes are the very things that destroy their value. Modding them and using them at the track or in the dirt.

Also, I see this thread going off the rails already, so I'll just say: I'm leaving the bumper alone.


​​​​​​ okay. As you were.