GMADD

Hi !

I just received my dc headers and going to install them next week.
Does anyone else have them on their coupe?

Does anyone know the power increase ?

I'll try and post pics next week.

Gsedan35

iTrader: (10)

They made 14hp on a sedan dyno'd by super street magizine. BUT, that was with a prototype Dc Sport true dual exhast as well, so you have to deduct a decent amount on account of the exhaust. And oem exhausts tend to gain more when replaced by aftermarket systems on the sedan since the oem sedan system is more restrictive then on the coupe. I would pin the header gains alone at 7hp to 4hp.

G352NV

iTrader: (13)

Did you order from summit? Ive been waiting months now.

GMADD

I already have a borla exhaust,r/t cats and injen CAI, hopefully I can get 10-15 hp more.

GMADD

No, I ordered from performance nissan, they arrived in about one week.I got the stainless steel headers.

Bahraini350Z

ordered it from summit and still waiting!!
expecting first of Aug.

GMADD

I was thinking of adding a crawford plenum , I know it will help but if I go with FI will there be any problem ?

myGspot

iTrader: (1)

DC is crap. It might look good... but they are not designed at all. I rather go for any type of JDM header vs DC. all they do it just imitate the design of the stock header and call it a day. No RD in it what so ever.

Had it on my other car and after doing more detailed inspection... found out the header was actually smaller in diameter on the inside then the stock header was.

i would suggest taking TRUE inside measuremnets of the diameter on both stock and DC and posting info(and i mean for each pipe and each opening). That is the only way to compare and to mod the car. This way you and others can see what they will gain by switching to new header. Just cause its aftermarket dont mean you gonna goin power from it.

djricepik

I don't even know where to begin responding to this post... How about the beginning...

JDM=good? I have seen lots of Japanese product that is CRAP. That is not to say that it is all bad, because there is much high quality product that comes from Japan.

Imitate the stock design & call it a day? Have you ever even been under the hood of a car? Most stock manifolds are cast pieces of junk. Also you have to take into consideration the space constraints under the hood and how that effects design. I know for sure that you have never been under a G35 or a Z because if you had you would know that it is ULTRA tight under there. There is only so much you can fabricate in such a tight space on these cars. Borla opted for a design that does not require the unbolting of part of the steering assembly during install, resulting in various lengths of primaries. DC opted for a little harder install (extra 5 min) but maintained as equal length of primaries as possible. If in your eyes that is imitating stock design, then ignorance is bliss...

Smaller than stock diameter? What vehicle was this on? I assume it was a Honda since that is was DC was previously known for. It had a tubular manifold? I find it very hard to believe that any stock application was running larger primaries then 1 5/8"...

TRUE inside measurements? What exactly do you mean by this? Are you talking diameter? Radius? Are you assuming that bigger primaries equal more power? You are wrong my friend. There is a fine line that you run are far as balancing pipe diameter, primary length and collector size to create power.

I suggest you do a little bit more research, or at least open your hood before you start putting perfectly good product on blast...

myGspot

iTrader: (1)

Actually i did open up my hood... as well as hood of many other cars. ANd i do know what i'm talking about. Cause for one i built up my last car all by myself.

The headers that i had on my Prelude... the OEM header was bigger then DC was. INSIDE DIAMETER = whic is what i call a true diameter of measuring the inner portion of pipes on my DC was smaller then stock. The collector the primaries... the mid section... all smaller. Design wasnt all that great either. I've seen other headers and i can tell DC was no where near quality unit. I dunno how much knowledge you need to come up with conclusion that smaller is not always better especially when comparing it to stock. I like to see something with smoother transitions in order to get better flow.

Mugen header was a much better header by far then DC. As far as some of the crapy JDM products out there. Yes i should have been specific to things. And i meant more along the lines of the higher up stuff. Like Fujitsubo etc.

I understand the tight engine bay area... prelude is a tight area to work in as well. So i know a thing or 2 about working on cars like that. But despite anything.. you can still come away with a good design.

neffster

iTrader: (2)

Actually,

Jason at Performance Nissan told me that the only reason they had the headers was due to someone advertising the headers at an incorrect price. They were advertising them at BELOW WHOLESALE. Jason took a look at the headers when they came in and IM'd me on Fresh Alloy and said that he thought the headers were a POS and "might" last a year or two. That was ok for him because he paid under $250 a set (going off of memory here) for either 3 or 4 sets. He said he would install them on his ride because he was going to a TT setup himself real soon and would just sell them as used when that time comes.

For what it's worth, Jason has seen Borla, Nismo, Stillen, DC and maybe a few others. He told me that DC was the cheapest of the bunch. If you don't believe me, his number is all over the internet.

djricepik

WOW! All by yourself! You get a cookie!

If there was some logic in your response I might listen to what you have to say. Are you trying to tell me that running 2" primaries on an H22 will give you the most power? You are crazy. I am not saying that smaller is better, but you have to match the design to the output of the motor.

Prelude as tight as a VQ35? Give me a break... I guess ignorance is bliss...

Bahraini350Z

From what I see, it is the cheapest(in terms of price)

djricepik

This does look like junk... you are right...

neffster

iTrader: (2)

Well I see 18 + pipes that have not been mandrel bent, rather they have been welded together cheaply, then polished only in some area. I wonder what the insides look like after all that welding? Can you say heat affected zone?

Why don't you "pro DC Header guys" ask Jason for yourself and (I'm trying to be nice) quit acting like little kids. Just because you spent money on a mod doesn't make it a good mod or a good purchase. Especially for the guy who hasn't even installed it yet, how can you be so much of an advocate of this header?

Factual Data Point #1 that should be mentioned. Super Street Magazine modified a G35 stock sedan. They saw a gain of 14rwhp on the dyno from the DC Sport headers and a prototype true dual exhaust. Keep in mind this was not a coupe. True Dual Exhausts on the sedan usually make over 10 rwhp by themselves so where are the gains from the DC Headers? I'll tell you where they are, in your head!

After installing the DC headers the sound of your car is MUCH louder than your car was with the stock headers, and if you never do a pre and post dyno run you'll "think" you're going faster when in all actuality you're just wasting your money.

Factual Data Point #2. Eagle1, one of the most well respected posters on this and other forums, races a blown G35 with about every mod known to man. He has done pre and post dynos with the Borla headers and got either 1 or 2 net rear wheel horse power due to his header mod. The stock headers are made very well. This is a fact that you should be proud of, not be upset with. Nissan did a FANTASTIC job designing the headers for the G35. They sucked a$$ with the Plenum and Y-Pipe (and the US Gov't made them suck a$$ with the restrictive catalytic converters), but the rest of the exhaust components were designed to be pretty good.

As far as my statements about my conversations with Jason, I am telling you the truth (as it was told to me on 5-28-2004 in an IM on Fresh Alloy by Jason himself). I was inquiring about a Fujitsubo Exhaust Group buy and Jason and I started IM'ing each other back and forth. Jason's words (paraphrased) were that the DC Headers were the poorest quality headers that he's ever seen, BUT for $249 he'll make a bunch of money, so why not buy them.

If you want to take a special photo posted on the Internet of some shiny steel headers and "assume" that they'll give your car a hp gain, fine. If you want to know about quality headers that produce hp, ask Jason what's the best. He'll tell you Crawford, Nismo, and maybe Stillen, but will tell you that DC is only for those who cannot afford better. He specifically told me that he would not even put them on his vehicle if not for the super cheap price and the fact that labor cost him very little.

Choose to believe what you want. The easiest thing to do is p/u the phone and call Performance Nissan and talk to Jason personally. 626-305-3000

I’ve spent enough time and effort on this post. If you choose to disregard the info I’ve posted, that’s fine. Please don’t go encouraging others to buy this mod, UNLESS you do an unbiased pre and post dyno and tell them the gains it produced. Thanks for reading.

myGspot

iTrader: (1)

Actually.... I DO.
I never said runining a 2 " primary is beneficial. DOnt put words in my mouth. WHAT i stated was... actual fact. MY STOCK h22 header had smaller opening then DC did. SInce you like to defend quality of DC defend that. Funny how you wanna battle me on this... yet you overlooked what i posted. Another thing is that Mugen header had a collector that was 2.25 as oppose to DC that was barely making 2" Stock was 2" on a dot. SO YEA.... DC is great.. I'm not even gonna go into the quality of welds and the brackets they put on it. Cause that Crap fell off ON EVERY PRELUDE that ever put on DC HEADER.
Thats not even the fact that it started to rust in certain spots. And it was Ceramic coated as well.
SO talk all you want. You dont like my explanation for inside diameter. Guess what... i could care less. I know what i want out of a header... and DC aint it. If you think they are all that... Go buy em. More quality stuff for those who want it.

YOu know... you actually sound like broken record...with your bliss comments. I think you live in a fantasy world. might wanna snap back to reality.

myGspot

iTrader: (1)

wow its amazing how a picture of a SHINEY object can make a sale. Man you should be a poster child for marketing campaigns.
with a caption... if we can make this fool buy ... others will follow

Just cause it looks good in picture dont mean squat.

Silly rabbit... TRIX are for kids.

350xfire

iTrader: (2)

Finally decided I was going to install mine, along with Crawford high flows.
The driver side went OK. Only one nut was almost impossible to tighten with my tools. I went and got an offset 14mm wrench and got it. BTW, when taking the steering shaft off, use a tie rod end removal "fork" and hammer gently until off. I tried removing by hand, but it was impossible. Driver side is finished. Except for a cat bolt that I will need someone's help with. Yes, I am tackling this all by myself. I don't have the buddies that come over and help me. I'm usually the sucker helping them.

The passenger side, OUCH. It was a pain to get the stupid coolant line off. I am 2 bolts away from getting the manifold off now. The last two seem impossible, but I'm sure I'll get them off.

Must have tools, 10, 12, 14mm sockets (deep and shallow), offset wrench 14mm, ratchetting box end wrench (not the thick cheap ones, the better thinner ones, got mine at O'Reiley's for $40 a set), extensions (get a full 24" one since it won't come appart on you while trying to work, need this for the cats), breaker bar and wobble fitting. Air tools not required, not much space to use anyway. I think that's it. Don't forget, lots of PATIENCE. I have been working on mine for about 6 hours so far. I estimate about 40% done.

Loren04G35

Why I don't any experience with DC Sports's VQ35 headers, their parts are far from junk. For Civic Si's, RSX's, Integra Type R's and Celica GT-S' they make the best headers in the industry. Their 4-1 single piece headers make the most power and torque over any other they have been tested against. Check out any of teh header tests in Sports Compact Car or Super Street. This is their first application at RWD though.

As a counter comment, I have a hard time on the other hand backing Stillen; who is supposed to make one of the best(and most expensive) headers. I've had 2 of their Y-pipes. The first has cracked on me 3 times. The second which was redesigned taking away the equal length tubes. If flowed so bad that when I dyned it made the same power as the stock pipe. I sold it immediately to another sucker and had the old one welded up one last time. I also have one of their exhausts. After 3 years, the muffler packing has deteriorated and if you shake it, it sould like it has sand in it. Stillen has no chance of ever getting my business again.

If anyone thinks the size of the tube is all that matters in flow, get off your lazy *** and enroll in a fluid dynamics course. Equal length tubes separate exhaust pulses. Because there aren't 2 pulses coming into the same volume at the same time, there isn't a need for as much volume. What happens when you go from a small volume to a much larger one? You lose velocity. You ideally want the maximum velocity of the exhaust without restriction. The target is then to have the tubing size the same as the exhaust port on the head. This will give you far more torque down low and the highest peak power.

Back in 93 Muscle Mustangs and Fast Fords did a shorty tube header comparison. The first on a 260hp car, equal length headers always made 5 hp more than unequal length headers consistantly manufacturer to manufacturer. The final result was in a set of MAC 1 1/2" equal shorty headers made 5-10 lb-ft more torque at all rpms and 5 more hp than all the sets of 1 5/8" unequal length shorties(16hp total). They even made 3 hp more than the 1 5/8" equla length shorties. The larger tube headers lost a little velocity. When they did a follow up test 2 years later, the larger equal length headers made more power when they went to a set of aftermarket heads with bigger ports.

If you still don't believe this, there is a very easy test that can be done. First measure the size of an exhaust port on a head. Get some clay and make a short cone that size. Find someone with a flow bench (we have Kim Barr Racing here in Dallas) and barrow a few sets of different headers. Put them on the flow bench and you will have the answer.

Road Warrior

iTrader: (16)

can you find a better set of headers for 360 shipped

they are certainly better than stock....guaranteed

by the way, the crawfords are welded too...i suppose they are crap also

crawfords