borla header measurments

[chunky]

header primaries: 1.5" OD
Header collector: 2.5" ID


The 2nd piece of the header necks down to 1.8" where it meets the cat.

pics will come soon. The header is going to get ceramic coated over the weekend and installed sometime mid week next week. :D

[Peking]

Sweet... what that run you?

[chunky]

2 piece semi-long tube header.

http://www.darksci.net/~chunky/header/1.JPG

Here's a look at the adapter flange to fit the stock cat.

http://www.darksci.net/~chunky/header/2.JPG

the other end of th adapter flange.

http://www.darksci.net/~chunky/header/3.JPG

the collector.

http://www.darksci.net/~chunky/header/4.JPG

the collector again, with flash.

http://www.darksci.net/~chunky/header/5.JPG

the flange that mates to the head.

http://www.darksci.net/~chunky/header/6.JPG

the flange up close.

http://www.darksci.net/~chunky/header/7.JPG

the backside of the flange. note how thick the header flange is.

http://www.darksci.net/~chunky/header/8.JPG

I got a free hat! w00w00.

http://www.darksci.net/~chunky/header/9.JPG

[chunky]

Originally posted by Peking
Sweet... what that run you?

header = 333 shipped. ceramic coating runs around 100 bucks locally. it's going to be finished with a silver ceramic coat. BLING.

[myeverlovinsir]

Very nice pics, I think Borla was smart to keep the baffle in the collector, this helps with the low end tq and It looks like they have welded it up along the sides, just like I did with my DC header. Congrats.:D

http://www.darksci.net/~chunky/header/3.JPG

I can see where you could do some work in the above pic. If you can I would try to make the transition smother than the straight edge you have. A little grade would help reduce the turbulance and improve flow. Just my .02 cents.;)

[chunky]

Originally posted by myeverlovinsir
Very nice pics, I think Borla was smart to keep the baffle in the collector, this helps with the low end tq and It looks like they have welded it up along the sides, just like I did with my DC header. Congrats.:D

[url]http://www.darksci.net/~chunky/header/3.JPG[/rul]

I can see where you could do some work in the above pic. If you can I would try to make the transition smother than the straight edge you have. A little grade would help reduce the turbulance and improve flow. Just my .02 cents.;)

hehe. don't worry, I already have plans to improve on borla's already solid design. :D

the ceramic coating is just the start. I can't wait to dyno test this header as I haven't seen any posted as of yet.

[Peking]

Originally posted by chunky
hehe. don't worry, I already have plans to improve on borla's already solid design. :D

the ceramic coating is just the start. I can't wait to dyno test this header as I haven't seen any posted as of yet.

Who did you get to do the coating for you? Also what else do you have planned?

[chunky]

Originally posted by Peking
Who did you get to do the coating for you? Also what else do you have planned?

the same guys that cryo treated my rotors. they're up in cumming, www.procryo.com

and I can't give away all my secrets can i? ;)

[anjapower]

welds don't look too bad, looks like a good product for the price. Compared to my comptech race header, the pipe seem a lot skinnier. I wish I had a digi-cam, but all four tubes start out thin, then get a little thicker, then a little thicker again, and then the pipes for cylinder 1&2, 3&4 mate together and become a little thicker, finally merging into the collector.

My adapter looks to be quite like the borla's, but without the hanger, and flanges on both ends. The only thing I'm wondering is why the adapter starts out at 2.5" but then has a lip on the other end, reducing diameter to just over 2". My comptech exhaust had a similar lip at the start, and right after, opened up to 2.5"

I'm wondering if I should bother getting the lips machined out, or just leave them be for now...

[chunky]

Originally posted by anjapower
welds don't look too bad, looks like a good product for the price. Compared to my comptech race header, the pipe seem a lot skinnier. I wish I had a digi-cam, but all four tubes start out thin, then get a little thicker, then a little thicker again, and then the pipes for cylinder 1&2, 3&4 mate together and become a little thicker, finally merging into the collector.

My adapter looks to be quite like the borla's, but without the hanger, and flanges on both ends. The only thing I'm wondering is why the adapter starts out at 2.5" but then has a lip on the other end, reducing diameter to just over 2". My comptech exhaust had a similar lip at the start, and right after, opened up to 2.5"

I'm wondering if I should bother getting the lips machined out, or just leave them be for now...

looks can be decieving. have you measured the diameters of the comptech tubing? I wouldn't doubt that the comptech has larger diameter primaries b/c it is a race header designed for engines that make power well beyond the stock redline.

The cylinder pairing for the comptech is the opposite of the borla, again, interesting. Toda pairs 1 & 4 and 2 & 3, just like the borla does (well, technically the borla uses a 4-1 merge collector, but the 1 & 4 meet above the baffle plate and the 2 & 3 meet below the baffle plate creating a certain degree of cylinder pairing.

The lip on the borla exists b/c it goes into the stock cat. so they needed to create that space to allow the pipe to slip over the stock piping but still have a smooth transition on the inside. The pictures don't show it well, but the inside is rolled very nicely and the transition is pretty smooth already.

The comptech probably has the lip for anti-reversion qualities.

[chunky]

well, the header got ceramic coated and installed.

http://www.darksci.net/~chunky/header/14.JPG

the ceramic coating job was nice.

As for the install. . . well, I had some issues, nothing major though. here are the basic steps you need to take to install/remove the header.

1) remove the cat from the header.
2) remove the front sway bar
3) remove the cat from the midpipe & header
4) remove the stock heatshield.
5) remove the bolts that secure the header bracket to the block. You won't need this bracket for the borla header.
6) remove the header bolts & nuts
7) remove the stock header.

installation is the reverse of removal.

Since the borla is a semi-longtube design, you can't install it from above like you can with the shorty headers. You HAVE to take off the front sway bar. Clearance is VERY tight between the header flange & the sway bar.

Seat of the pants tells me that it's made a very positive difference at all engine RPM. Definitely worth the extra money I paid. dyno sheet coming soon.

[DC5RK20A]

Originally posted by chunky
the flange that mates to the head.

http://www.darksci.net/~chunky/header/6.JPG

the flange up close.

http://www.darksci.net/~chunky/header/7.JPG

the backside of the flange. note how thick the header flange is.

http://www.darksci.net/~chunky/header/8.JPG


Wow those are not very clean welds on the piping to the flange. Did you dremel them some to make it more smooth. And they didn't weld the piping on the other side to the flange. I hope it gives you some decent gains.

Chris

[chunky]

Originally posted by DC5RK20A
Wow those are not very clean welds on the piping to the flange. Did you dremel them some to make it more smooth. And they didn't weld the piping on the other side to the flange. I hope it gives you some decent gains.

Chris

the welds aren't any worse than the welds you'd find on a dc sports header. granted, it's not as pretty looking b/c the header is not polished, but they are good clean welds.

I thought about having the backside of the flange welded around the primaries, but i was thinking about it and I'm guessing the backside wasn't welded to allow the pipe to expand as it heats, and I felt it best to leave things as is.

The gains are nice, very nice in fact. :) I have a friend who just put a h22a into his '92 accord sedan. 200hp + 2500lb car, and I pulled on him on a 20mph to 80mph run.

dyno will be coming shortly. :D