I purchased a set of comptech headers and j pipe recently. After looking at them with a couple friends of mine we decided to upgrade the collector flanges on the headers and completely make a new j pipe with a better design. We ordered two 2 1/4 v band assemblies for the collector flanges on the headers, only a 1/4 larger than the comptech size. Were going to make the j pipe design a lot better instead of doing that half turn on the rear pipe. It will all merge together and have a 3 inch v band assembly. The mid pipe will also be 3 inch all the way back. Were completely removing the test pipe and mid muffler. It will then split into each comptech muffler. I will also use two more v band assemblies for each muffler connecting to the mid pipe. I might stay with the 2 inch or go a little larger I'm not sure yet. It might seem like over kill but you have to remember I will also be spraying the car with at least a 100-125 single nozzle wet shot very soon.

I'm open for any opinions or pictures of other peoples setups.

 

I'm not sure if I visualize what you're doing. Keep in mind the J pipe design is built/tuned to provide equal length runs from the front and rear banks at the merge point to synchronize the pulses from the cylinders. This helps with the scavenging affect. If you shorten one of the runs which is what I think you're talking about, you potentially may lose flow from the original design. If you have two cylinders pushing exhaust into the collector at the same pulse or out of sync, you could cause more turbulance and restriction. I would be surprised if you got much gain out of re-designing the J pipe. I've seen gains post J pipe when others have used an exhaust cutout removing all restriction post j-pipe so that area is worth focusing on.

 

^good point

 

I'd leave CT designs alone. They already are engineered. Why reinvent the wheel?
But if you got the time $ go for it.

 

yea i completely agree with ALLOUT

the rear collector bends in that 270 degree circle so each cylinder has the same RUN (distance) before hitting the cat.

that's part of the engineering, and is what u said u wanna remove?

i don't think that's as benneficial as u may think. but i am still curious.

i had a v6 ford probe before and it has the EXACT same looking J pipe. same design concept. its pretty standard.

u think it's easier for them to make that insane bend than just going straight like u want to. think about it

 

i disagree with the above sentiment. If you are going to change the design you can always run an equal length pipe from both cylinder banks backwards towards the cat and merge the behind the cat. Adding a loop to the rear sections of the jpipe will allow the pipes to be the same length.

 

Thats ONLY if he adds the loop. It sounded like he was going to get rid of it

 

i suggested something similar a while back u might do a quick search ... my idea was to use RV6 equal length j pipe and turn the primarys into mid length using a 3to1 burns collector at the j conection

 

it's funny how are headers add more to our cars J32a2 than any other car with the same size motor and yet u wanna get even more power from it? lol

if u really wanna do something custom talk to P2r they made a few sets of custom headers and they got more power from them than the CT headers, but i forgot how long they said it took to make those bad boys

 

The ct headers arent perfect, you can extract a lil more power with custom headers. I dunno about hacking up comptech headers tho. I would have started with a cheaper set or do full custom if I went that route.

I have tried to get p2r to make me a set of headers. I had the money ready to send payment anytime(which would have been around $1200). He just was not interested in doing it. I think he has moved on by now.

 

I would like all 6 to merge together equal length behind the trans. I remember years ago there was a set made (cant remember the name) and they looked wild. Thats what i would like.

 

Thanks for all the replies and opinions everyone. I'm still going to cut the 2 inch 3 bolt flanges off the headers and use 2 1/4 v band assemblies. With the j pipe will show you how comptech should of engineered theirs lol. It will be a lot better design trust me. Were still keeping it equal length, it will just merge together further back. You have to remember I'm not using a cat and making a custom mid pipe so we have plenty of room to play with. I will post pics during the process. Here's a pic of the rear header and the new v bands. Don't mind the ugly header, they will be ceramic coated once we weld the v bands on.

 

You do realize that the pipes won't be equal length no matter how far back you
Merge them right? The loop MUST be there. Engineers designed these, not just some dudes with a welder.

 

You would get more out of your money by simply gasket matching the heads to the headers but,comptech's weld job will not allow this.
Their welds are to close to the flange,I have a pair.
The obx one's are welded deeper in the flange so you could match them up without grinding into the weld. I have those too.
I would not change the design of the J pipe unless chopping it apart to run dual pipes. A pipe off each header.

Are you planning on running a large single exhaust or still going to have it split in the back ?
Can't wait to see the progess with this

 

I know your talking about these Barboys. http://i1119.photobucket.com/albums/...h/7d82462e.jpg
But you can do like I said a wile back 3to1 into 2.5" all the way. But u will benefit more with a cutout right the cat/ O2 this would alow proper air/fuel mixture. If you just connect the rare jaded strait dnw into a bigger pipe you would still gain some power but loose lowend TQ

 

IIRC, you are referring to the 'Prototype' equal length headers. They along with others, are discussed on the thread below:

https://acurazine.com/forums/showthr...g+tube+headers

Unfortunately, there is no pictures in that thread that depict their look.

Allegedly, NVA-V6 is grinding out a set of custom long tubes for civicdrivr. Perhaps when he gets back from his forum vacation, he can chime in on their status.

 

aww that pic made it all clear now i see.

just merging the pipes after a longer run and with more symetry. i like it.

that must yield some extra ponies

 

 

our ideas are similar ... start with RV6s j pipe which is alread perfect and extend the comptechs priamrys down to it using equal length tubes ...

 

Maybe I'm not explaining it right in words. The setup RooEng posted looks overkill for me and RV6'S j pipe looks like a nice design. Were not 100% sure how were going to do it yet the first step is to get the v band flanges welded on the headers, get those ceramic coated, and installed. Then we will start building the j pipe off that and last will be the mid pipe which should be a fairly simple design.

I'm not trying to squeeze every little hp/tq out with the new setup. The main thing is it will have a little larger pipe diameters, better merge, and all v band assemblies. Hopefully it will make more power than a out the box comptech setup. We can always dyno the car as is right now with oem headers and j pipe. Then after with headers, j pipe, and new mid pipe setup to compare the differences if we want to compare just for curiosity.

 

yes, please.

 

I most likely will just to see.

 

yea man i'd like to see another b4 and after dyno as well.

not many dynos have been going down (being posted) and the last yr or 2.

 

mad props for doing it i want to see it finished soon

 

I have a nice 1080 hd camcorder that I can use. I'll probably be able to dyno the car within the next week.

Thanks I'll keep all you guys updated in my build thread!

 

I would like to take a set of those, then where the merge is have the other side Y back off to dual pipe and use that connection (if done properly) as the "X" pipe

 

I stopped by my friends shop tonight. I was able to cut off the collector flanges from the headers. I still have to have one of them tig the new v bands on so I can drop them off to get ceramic coated tomorrow. I'll post post a couple pics once they're welded on.

 

We got the new flanges welded on and I dropped them off to get ceramic coated today.

 

Are u gonna use those clamps for after or just for now ?

 

:pop:

 

What do you mean exactly? Please explain.

 

Clamps? Those are v-bands, and permanent. Things will go together, come apart a LOT easier, plus straight baller

 

Lmao that's what I was thinking. Those v band assemblies are expensive!! I still have to buy one 3 inch and two more 2 1/4 for the split in the rear. Exactly like you said it will make things a lot easier.

 

im working in beverage plants we are using this clamps to connect pipes together...

BTW i can get them for free

 

 

 

Are you meaning v band assemblies exactly like pictured? If so get me some!!! I'll throw you some $$$$

 

Lmao hahahaha

 

One more question. When welding did you guys filled pipes inside with argon too ? Pm me what and what sizes you need

 

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