What makes the JDM header so special?
How do these headers compare to the leading GREDDY, COMPTECH, MUGEN AND EVEN DC SPORTS????
Please explain
also, to install these headers onto a 2001 GSR what would i need in addition to complete it.
Thanks

 

they are good becuz its "jdm"....DON'T YOU KNOW?! anything labeled "jdm" is good buddy!

 

2.5 Inch Collector, once you got cams, this can be a big bottleneck... If you get the header, you should get a 2.5 inch cat (need a new one anyway prob for the diff header configuration), and ideally get a full 2.5 inch catback as well...

I have a puny Neuspeed 4-2-1 header and it's prob choking me off quite a bit...

FB

 

Oh BTW,

There are the JDM headers with 2.5 inch collectors, but you can also get the US "custom" types: SMS, HyTech.

You will pay a premium for the units with 2.5 inch collector, but if you're going all out it's "worth" it...

FB

 

actually, the DC JDM 4-1 is the same price as the rest of their headers...the only place you have to spend more money is for the custom cat...which are about $150

 

SOmeone measure the DC JDM and said they are actually 2.35" (60mm) inner diameter not 2.5". I need to measure the JDM 4-1. DC is cheaper but them you are comparing DC build quality to OEM HONDA parts. (No comparision IMO)

2.5" collector and HONDA engineering are the big advantages plus it has been shown to do well on Integras over several aftermarket brands. The comparision I remember most was lip's dyno plot with the Toda cams and RSR vs JDM dyno plot. THe dissference was something like 178 for the RSR and 192 for the JDM 4-1

 

i care how stuff looks in my engine bay...and stock headers are nasty looking...and the jdm 4-1's are way too expensive...thats why I'm goin DC sports

 

I care too, but my approach may be different. I like the Jet Hot (Flat black) on the JDM 4-1 and Heat shield so it loooks completely stock.

 

i can't believe they would do this with various people making 2.5" adapters and related stuff. their site says " features the larger collector outlet used on the jdm integra." i will consider the dc when the time comes but oem jdm price continues to fall. options has the 98 spec jdm itr 4-1 for $399 for example. hmmm...maybe the text in their description will shed some light, fwiw. "60mm collector flange must use special 'donut' gasket and requires modification for most applications."

 

the dc jdm is an exact reproduction of the OEM JDM

 

I have the JDM ITR header and I have had a DC 4-2-1 header (different car) and I can say that the quality on the JDM header is FAR superior to DC headers. If you're so concerned about looks get it coated or hell, do it yourself with a can of automotive engine paint ($7 per can).

 

Here's a quote from a previous post: "My JDM DC 4-1 just came in. I discovered that the collector (near the O2 bung) is actually 60 mm OD. Only the last piece where the donut lies on is 2.5" OD (63.5 mm). I think the JDM 4-1 is effectively also 60 mm OD because it's double walled near the donut. Maybe, that's why all japanese aftermarket exhausts like the Mugen are 60 mm OD."

Also, the DC JDM is most similar to the Mugen JDM, not the OEM JDM.

 

It's actually modeled after the Mugen header or so I have been told by many people. (like ninjaman said).

I've also heard rumors that the primaries on the DC JDM are actually larger than the JDM. Member Dan said that. He uses the DC JDM and claims that it's a nice piece. I've never had a single problem with my DC 4-2-1, the quality was perfectly satisfactory. I'm changing to the DC JDM just to "open her up" for the CTR cams and pistons.

 

is anyone yet making a cat that i can pull out of the box and bolt on to a jdm header and my exhaust? (not a test pipe). no big deal to customize but this would also be cool. i would also like to see dyno of dc jdm vs. oem jdm. i would also like an '04 nsx. tia.

 

Go Mifune: which color would you like on that NSX? I get on that right away

 

Yes, contact Dave at SMS Products and ask him about the 2.5" Carsound cat flanged for a JDM header. smsproducts@carolina.rr.com

 

JDM baby ya!

 

i guess primer gray because it seems like the only way to not get harrassed and flamed these days is to look bone stock/ultra sleeper or worse.

 

cool! i'm gonna start header shopping right after i pass smog with my 7 1/2 year old stock cat.
(just to be safe).

 

The DC JDM 4-1 has a 2-1/2" OD collector (told to me by the DC folks). That makes sense since it's made here with US spec tubing. The ITR JDM has a collector OD of 65mm (2.56"). The DC JDM has 1.75" (US spec) primaries while the ITR JDM utilizes 1.69 (43.5mm). All tubing is sized by the OD not ID. ID is determined by knowing the wall thickness (18g, 16g, etc). Smaller the gage the thicker the wall. 18g = .049" and 16g is .065". Therefore the ID of the DC JDM should be around 2.37" since it's built from 16g material. Now the ITR JDM header has an anti reversion chamber, i.e. a tube within a tube, I measured the ID of it at 2.16". So the smaller tube size of the ITR JDM and collector should promote a better mid range than the DC JDM.