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"Due to the combination Catalytic Converter/Exhaust Manifold, or Mani-Cat, you are unable (technicalities aside) to pass emissions with an aftermarket header installed"

I will add a bit more detail here if permissible as this thread is about header/cat and the attendant legality's.
The issue with replacing the stock mani-cat as far as the EPA is concerned is this. Start-up emissions. Any car emits more hazardous emissions during (cold) start-up than during several hours of running when the cat is up to operating temp. Hence, Ford engineered the primary cat (the mani-cat) to be as close to the exhaust ports as possible to enhance the heat-up of the cat.
I talked with my local EPA guy about running a wrapped header to a HF cat and this initial 'heat-up' was the primary concern. But! they waffled a bit, and as there were no supporting facts they went back to the letter of the law (EPA doc 20460).
This means that if you(we?) can prove that a wrapped header with a EPA certified HF cat meets or exceeds the OEM spec for emissions during a cold start then there is a very good chance that you(we) could get an exemption. Note: After a cat is warmed up, there is no issue as they all 'do the job' pretty much the same.
An example of such a cat would be a cat that has a pre-heater (Tom mentioned them in a prior thread). I have not been able to find any such cat in numerous searches as they seem to have been replaced by non-powered 'racing cats'.
So if you have a good head for this stuff (or maybe just the tools) it is quite possible that a header/cat combo could be EPA legal.
Note: An exemption is not a CARB certification. But you would not need that unless you intended to sell a header/cat combo.
 

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BodyKits=PantiesDrop
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Discussion Starter #22
Sounds like an awful lot of money and redtape will be involved but I give anyone willing to try it my best wishes!
 

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Sounds like an awful lot of money and redtape will be involved but I give anyone willing to try it my best wishes!
It really depends on a persons resources. Access to a calibrated sniffer? Do a before and after test? Maybe a heat gun? An exemption is not that hard to get if you have some accurate documentation. CARB is another world though.
 

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Im in a related field. If u can pass inspection and OBD 2 tests, startup will be your only issue. The cat needs to be as close to the collector as possible, and the header needs to be wrapped and or coated. BUT... If you cat is already hot, that will help alot, so wrapping the cat will aid. Only problem is as stated a few posts up, you modified the system which EPA/CARB frown upon. Tuning for a lean startup to heat the cat faster will not work (dont know if its even possible), because your CO2 an NOx will be higher then the normal tune and the cat wont be warm enough yet to convert it.
 

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Also...my company is testing a heater grid system for another company. Basically theres a honeycomb-ish looking grid right on the inlet face of a DOC (diesel oxidation catalyst) and with massive amounts of electricity can heat to +750*c really quick. But good luck with that, all the circuitry and power needed, and the grids fail (burn to an open circuit). But it does work.
 

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Im in a related field.
Good! You are now our resident expert! [headbang]
So what do you think? Would a wrapped header/flex pipe retain enough heat to warm a retail aftermarket HF cat (OR a racing cat) as quickly as the OEM setup? Would a cold header/flex pipe act as a heat sink initially to rob the cat of startup heat?
Is +750*c (1382 degrees Fahrenheit) typical for a gas engine? Or could you obtain the EGT of a Duratec engine? Is that the light-off temp for a cat?
Notes:
I specified header wrap as from my reading it retains more heat (I.E. works better) than a jet coat or similar.
I did not specify wrapping the cat as I don't know if doing so is recommended. Would the cat burn out prematurely?
 

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So what do you think? Would a wrapped header/flex pipe retain enough heat to warm a retail aftermarket HF cat (OR a racing cat) as quickly as the OEM setup?
^--No. Its too far down stream as compared to oem. It would be delayed, but i dont know by how long.

Would a cold header/flex pipe act as a heat sink initially to rob the cat of startup heat?
^-- Most definetly

Is +750*c (1382 degrees Fahrenheit) typical for a gas engine? Or could you obtain the EGT of a Duratec engine? Is that the light-off temp for a cat?
^--Not at start up or idling. Decent rpm and alot of load can yeild those temps. But it depend on what engine (i4 or v8), catalyst placement, etc... I can possibly get egt of a 2.3 at start and for a few sec. But then we go to a specific rpm and load, then alter timing and fueling, ect...i will see if i can dig some data up. Wont be right away though.
We refer to lightoff as an overtemping of a catalyst, so i cant tell u exactly when the cat reaches the optimal conversion temp. We age gas catalyst to what would normally be about 150-200k miles in about 85-100hrs, depending on the aging requirements. But i have seen catalysts reach 2400*f for long periods and live. But i have also seen then melt.

I specified header wrap as from my reading it retains more heat (I.E. works better) than a jet coat or similar.
I did not specify wrapping the cat as I don't know if doing so is recommended. Would the cat burn out prematurely?
^^yes header wrap retains heat (and moisture) better. So idealy you would want wrap on the cat, but im not 100% sure about the header...maybe both coating and wrap? You'd want it to retain heat as well as get it to the cat. The wrap on the cat will speed up the aging of the cat, but i dont think a noticable amount. Im not 100% sure what precious metals and chemistry are in aftermarket/high flow cats so that one im not too sure about
 

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Following may be useful>>
Ref: http://74.125.95.132/search?q=cache:yL8z6Wl7IHQJ:www.challengers101.com/ExhaustGasTemp.html+internal+combustion+engine+exhaust+temperature&cd=6&hl=en&ct=clnk&gl=us&client=firefox-a

When gasoline and air are mixed in such proportion to have complete combustion, in other words all the fuel and all the air are completely used, the resulting temperature will be in the 1500 F range. This temperature is far too hot for an internal combustion engine to sustain for any length of time without incurring catastrophic failure.

If the chemically perfect fuel-air mixture is altered, either by adding more air, or by adding more fuel, the combustion temperature will cool down. However, the amount of fuel available to the engine is directly related to the power that the engine produces. Thus, the fuel-air mixture is made richer to lower the combustion temperature, rather than leaner.

The maximum EGT considered to be safe is in the 1200 F to 1300 F range, depending upon the engine manufacturer, where the EGT probe is located, and the type of cooling system employed. A fuel-air mixture that produces an EGT above the recommended maximum is considered too lean, even though it is still too rich for complete combustion.

Somewhere on the web I found a graphic of the measured temps of a typical tube header. I will try and find it again.
 

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straigh pipes?

i have a 2.0 duratec, i want to put the FSWERKS 4-1 race header on with the 2.5 FSWERKS exhaust but im debating cutting out the muffler and replacing with a straight pipe...not worried bout enviroment shit, more/less power? i am also running a 67mm throttle body and a ram air intake, stock tune...
 

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i have a 2.0 duratec, i want to put the FSWERKS 4-1 race header on with the 2.5 FSWERKS exhaust but im debating cutting out the muffler and replacing with a straight pipe...not worried bout enviroment shit, more/less power? i am also running a 67mm throttle body and a ram air intake, stock tune...
Should have more. But a tune may get better results for the $$. D2 responds well to enhancements though, so not sure. Suggest you keep the muffler if possible until after you try header, only in that many have posted there surprise in how loud the exhaust gets. Got a pic of your ram air setup?

Edit: sorry! you said D2. You will prob want smaller primaries. That would be the OBX header. The FSWERKS header will prob kill you low end torque as it is for the D2.3.
 

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i have the HPS cold air, but with a 90degree bend and an extention to the front fog light cover, i cut a few slits in the cover to give the car direct air flow, actually had a decent result...so its not a real "ram air" but same concept...
 

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BodyKits=PantiesDrop
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Discussion Starter #32
It will be unbelievably loud with a straight pipe and a header...
 

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can i run a header without a tune? will this hurt my engines life? i am stuck without a tune because they dont have the 010 sct code out yet.
 

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I can't seem to find the F2 header on their website. Are they not selling it anymore?
 

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i found this on ebay. i have an '05 ZX4 S with the D20...this is basically a direct fit right? would it be worth the trouble of buying it and putting it on or will i see minimal if any gains?
TIA
 

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Just a quick question, I didn't see anything about this in the forum (i looked real good)

I bought a 3" Magnaflow Non-chambered(i believe) muffler... I originally got it for a buddies ranger, was wondering if it was worth trying out. I think I already know the answer, but wanted to see what other people thought. If not, anyone wanna buy a muffler? lol
 

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anyone have sound clips of there complete header/exhaust?
AEM CAI, OBX header, Magnaflow exhaust

In person this thing sounds AWESOME!!!!!!!!!!

The bottom pic is actually a video if you click it.





*VIDS ADDED*
Here are some more vids. Each pic is a clickable link.
1st vid: Me doing a short pull about 3/4 throttle.

2nd vid: Giving a bit of throttle, not much though.

3rd vid: waking the neighbors
 
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