Cal Club Autocross Forums

I need a header collector flange to bolt to the factory style cat. Its a pretty oddball piece it seems.

Couple of questions for the Honduh crowd.

What size is the common DC Sports 4-2-1 header outlet? I'm assuming somewhere between 1.75" and 2" but anybody know for sure?

Does it use one of those donut gaskets?

Where the heck would you get a flange like that?

Anybody got a cheap old civie header I could cut up? Mild steel preferred to make welding easier. I have a DC Sports 4-2-1 header on the car, but its in great shape and I'd hate to cut it up in sacrifice. Especially when I have no idea if its wild replacement will even work, or be legal next year.

BTW-At the Evo school I figured out why I've been having trouble shifting. The linkage rods are hitting my exhaust clamp. Should by an easy fix. The tranny shifted so nice back when Eric first rebuilt it, hoping to return to those good ol' days.

Steve Ekstrand wrote:I need a header collector flange to bolt to the factory style cat. Its a pretty oddball piece it seems.

Couple of questions for the Honduh crowd.

What size is the common DC Sports 4-2-1 header outlet? I'm assuming somewhere between 1.75" and 2" but anybody know for sure?

Does it use one of those donut gaskets?

Where the heck would you get a flange like that?

Anybody got a cheap old civie header I could cut up? Mild steel preferred to make welding easier. I have a DC Sports 4-2-1 header on the car, but its in great shape and I'd hate to cut it up in sacrifice. Especially when I have no idea if its wild replacement will even work, or be legal next year.

BTW-At the Evo school I figured out why I've been having trouble shifting. The linkage rods are hitting my exhaust clamp. Should by an easy fix. The tranny shifted so nice back when Eric first rebuilt it, hoping to return to those good ol' days.

If the bisi header outlet is a 2.5... i would strongly suggest installing new flanges on the cat and the header to adapt the 2.5 into the cat. I run a 2.25" cat and redid my collector flange to 2.25 as well.

Good luck ekstrand with your Bisi header, you are going to need it.
I would not cut up your DC header.

The whole process is a pain...
The outlet on the new header is a 2"ID. I think he might have shrunk it down for our use. The whole idea of a super hi revving basically stock engine having to lug out of low speed corners pretty well freaked him out. So he said he wanted to make a few changes to the standard V2 design for an ST specific version. But I didn't trust that the outlet would correctly locate the cat so I took on that task... Arrgh... So I have to fit, determine exactly placement, locate a flange, weld up, test fit, ceramic coat, reinstall, retune the car. Each time in the interim stages reinstalling the DC header to load the car up.

Main advantage over the DC is probably weight. ;)

And the whiney types that think its illegal because of flowpath concerns would flunk my law class. Think it through, gesh.... We would have to go back to stock manifolds. Yuck. And the cost argument, huh? And emissions legal DOES NOT mean CARB E.O. That is a California thing. Our rule set is based on federal emissions. Federal emissions require stock emissions controls like EGR ports to be in place and the CAT to retain its stock physical location. The "Spec Civies" are OBD0 cars so you don't have to worry about throwing CELs and such. The arguments all based on fear are really silly if you think it through. Besides, the final version of this thing won't be hard and it will be $500-$600 that isn't a scary number considering the full retail price of a DC Sports 4-2-1 two piece. I love the people who set up the cost argument and base it on some killer used deal they got off craigslist. Once this header is available there will be used ones and Chinese knock-offs of it too. Its racing. Some people have blueprinted engines and transmissions, some don't. Some have all fresh parts and bushings, some don't. Some have the lightest widest wheel available, some don't. Some have expensive double and triple adjustable shocks where each corner is more expensive than any header, some don't. Some have worked hard to get their cars fully lightened, some don't. Some have the best and lightest exhaust available, some don't. Some have fresh tires, some don't. Some work on their cars and test test test, some don't. Some work on their driving, some don't. Some scrawny little guys weigh 134lbs, some don't. Some drivers have talent, some don't. Get over it. Go back to Farmville or MafiaWars and leave the racers alone.

Why do you need a stock flange? Won't a slip fit connector work?

Steve Ekstrand wrote:And the whiney types that think its illegal because of flowpath concerns would flunk my law class.

To me that is not the reason why it is illegal. I would suggest test fitting it first before you go through all the trouble of making a flange that will work with it. You will find a couple of problems that are beyond the flange. When you try to contact the Bisi god himself, he will toss you to the side and claim he knows all for our class and that it fits regardless of what anyone says.

Steve Ekstrand wrote: Some work on their cars and test test test, some don't. Some work on their driving, some don't. Some scrawny little guys weigh 134lbs, some don't. Some drivers have talent, some don't. Get over it. Go back to Farmville or MafiaWars and leave the racers alone.

Test-Negatory
Work on Driving-Negatory
Talent-Negatory

Farmvill and MafiaWars! Sweet!
The only reason I can do OK every now and then is my header...Thanks for the blood sweat and tears Curt/Paul/Will.


Anyway...Can't you just attach the header only and then have an exhaust shop take care of the rest? It'll be loud during load and unload with no muffler, but at least you don't have to put the DC on and off over and over.

Sebastian Rios wrote: Test-Negatory
Work on Driving-Negatory
Talent-Negatory

Farmvill and MafiaWars! Sweet!
The only reason I can do OK every now and then is my header...Thanks for the blood sweat and tears Curt/Paul/Will.


Anyway...Can't you just attach the header only and then have an exhaust shop take care of the rest? It'll be loud during load and unload with no muffler, but at least you don't have to put the DC on and off over and over.

Seb, that header is beyond what an exhaust shop can do... Also your header is sooo 2005, the header is so much different now.

Sebastian Rios wrote:The only reason I can do OK every now and then is my header...Thanks for the blood sweat and tears Curt/Paul/Will.

Screw you and your rules

deleted

Jon, thanks for burning our bridge. I will NEVER tell you anything again.

Jeff Wong wrote:Jon, thanks for burning our bridge. I will NEVER tell you anything again.

deleted.

i thought it was about "bisi (himself)" we didnt want to talk about. ;)

After so many years, ST exhausts still produce more drama than a daytime soap.

Got a pic of the header installed Steve? I've always thought Bisi's "bundle of snakes" header for the D-series motors was one of the neatest around.

As for flanges, I don't see why you can't do slip-fit as John suggests, or hack the flanges off both sides and do a V-band.

Jason Rhoades wrote:After so many years, ST exhausts still produce more drama than a daytime soap.

Jason Rhoades wrote:After so many years, ST exhausts still produce more drama than a daytime soap.

Got a pic of the header installed Steve? I've always thought Bisi's "bundle of snakes" header for the D-series motors was one of the neatest around.

As for flanges, I don't see why you can't do slip-fit as John suggests, or hack the flanges off both sides and do a V-band.

Jason- If I understand the rule right, and I don't claim to... I think you can toss the flanges and weld in whatever you want. BUT! You can't use a direct fit cat because the number that makes it legal is for how it comes out of the box. You'd have to use a universal application one sized right and approved for the civic assuming such a thing exists and then that could be put in how you wish as long as the brick stays in the stock physical location. Silly, but... That's how I read it. Any differing opinions????

Steve Ekstrand wrote:

Jason Rhoades wrote:After so many years, ST exhausts still produce more drama than a daytime soap.

Got a pic of the header installed Steve? I've always thought Bisi's "bundle of snakes" header for the D-series motors was one of the neatest around.

As for flanges, I don't see why you can't do slip-fit as John suggests, or hack the flanges off both sides and do a V-band.

Jason- If I understand the rule right, and I don't claim to... I think you can toss the flanges and weld in whatever you want. BUT! You can't use a direct fit cat because the number that makes it legal is for how it comes out of the box. You'd have to use a universal application one sized right and approved for the civic assuming such a thing exists and then that could be put in how you wish as long as the brick stays in the stock physical location. Silly, but... That's how I read it. Any differing opinions????

dibs on DC header?

I'll probably be running the DC header for a long long time.

Steve Ekstrand wrote:

Jason Rhoades wrote:After so many years, ST exhausts still produce more drama than a daytime soap.

Got a pic of the header installed Steve? I've always thought Bisi's "bundle of snakes" header for the D-series motors was one of the neatest around.

As for flanges, I don't see why you can't do slip-fit as John suggests, or hack the flanges off both sides and do a V-band.

Jason- If I understand the rule right, and I don't claim to... I think you can toss the flanges and weld in whatever you want. BUT! You can't use a direct fit cat because the number that makes it legal is for how it comes out of the box. You'd have to use a universal application one sized right and approved for the civic assuming such a thing exists and then that could be put in how you wish as long as the brick stays in the stock physical location. Silly, but... That's how I read it. Any differing opinions????

Seems like a safe (wise!) interpretation. Walker 15051. Would be willing to bet it's the same brick used in their direct-fit app. I'd suggest centering the brick in the flow path the same place the stock brick is centered.

Catch-22

If you select flow path instead of physical location, you are illegal under the opposing interpretation of the rule. There is no way to be more conservative. Depending on the interpretation there is only one proper placement. I argue that the flow path interpretation makes EVERY car with a header illegal in ST. It has to be physical location, and physical location is what matters under federal emissions rules regarding replacement cats.

Page 24, June '09 Fastrack.

Steve Ekstrand wrote:Catch-22

If you select flow path instead of physical location, you are illegal under the opposing interpretation of the rule. There is no way to be more conservative. Depending on the interpretation there is only one proper placement. I argue that the flow path interpretation makes EVERY car with a header illegal in ST. It has to be physical location, and physical location is what matters under federal emissions rules regarding replacement cats.

What I meant by that was physical location laterally and longitudinally along the car's underside. Mark a location in the exhaust tunnel where the stock cat was centered and make sure your aftermarket cat is centered there also.

Your header tubes can go to the moon and back (flow path length is free) so long as the cat is in the stock location.

Jason Rhoades wrote:

Steve Ekstrand wrote:Catch-22

If you select flow path instead of physical location, you are illegal under the opposing interpretation of the rule. There is no way to be more conservative. Depending on the interpretation there is only one proper placement. I argue that the flow path interpretation makes EVERY car with a header illegal in ST. It has to be physical location, and physical location is what matters under federal emissions rules regarding replacement cats.

What I meant by that was physical location laterally and longitudinally along the car's underside. Mark a location in the exhaust tunnel where the stock cat was centered and make sure your aftermarket cat is centered there also.

Your header tubes can go to the moon and back (flow path length is free) so long as the cat is in the stock location.

thats how i saw the rule as well. I installed my new aftermarket cat by centering the brick where the old brick was centered at.

Jonathan Lugod wrote:

Jason Rhoades wrote:

Steve Ekstrand wrote:Catch-22

If you select flow path instead of physical location, you are illegal under the opposing interpretation of the rule. There is no way to be more conservative. Depending on the interpretation there is only one proper placement. I argue that the flow path interpretation makes EVERY car with a header illegal in ST. It has to be physical location, and physical location is what matters under federal emissions rules regarding replacement cats.

What I meant by that was physical location laterally and longitudinally along the car's underside. Mark a location in the exhaust tunnel where the stock cat was centered and make sure your aftermarket cat is centered there also.

Your header tubes can go to the moon and back (flow path length is free) so long as the cat is in the stock location.

thats how i saw the rule as well. I installed my new aftermarket cat by centering the brick where the old brick was centered at.

Brick location? I would be more worried about flange location. Ask Mr. Kalman...

...and if I were king, ST cars would have stock manifolds and cats...

Curt Luther wrote:

Jonathan Lugod wrote:

Jason Rhoades wrote: thats how i saw the rule as well. I installed my new aftermarket cat by centering the brick where the old brick was centered at.

Brick location? I would be more worried about flange location. Ask Mr. Kalman...

...and if I were king, ST cars would have stock manifolds and cats...

I agree Curt - at the very least, if a beginning competitor and any PC in the country can't agree on a common interpretation of the rule, it either needs to be made clearer, or removed. Sometimes the latter is a lot easier.

In regards to flanges, I suppose to be really careful one might want to preserve the stock forward flange location in addition to centering the cat brick. Moving the forward flange rearward, even with the same brick-center coordinates, would feasibly allow one to use "longer" primaries (I know, the whole flow path contradiction thing) that otherwise possible.

You also don't want to modify the replacement cat so thats its inlet or outlet diameters are any greater than how it comes out of the box (2")- if you were to cut it up a bunch, you could expand in the inlet or outlet ID's by using the tubing section that's expanding/contracting to/from the larger middle brick section.