Porting exhaust manifolds

[KAOS_3.0]

so I was prepping my exhaust manifolds to paint them, and noticed how horibly restrictve the ugly welds between the manifold itself and the flanges are. theres almost an 8th inch step all the way around each opening, and the weld sagged into the openings on the front side manifold pretty bad.

o snch I happeedtohave adouble cut porting bit laying around, slappedit on the drill press and fixed thi litle problem.

here' some pics:

 

[BrApple]

with headers being $220 shipped iirc no one bothers doing anything else ...

 

[KAOS_3.0]

yeah, I sort of enjoy passing emissions and not destroying the earth.

not to say I'm never going to get headers, just saying I think a good high perf main cat and a better y pipe are in order first.

BTW, how would you explain gutted precats? I guess EVERYbody doesn't just get headers. also, how do the welds look on the headers? are they already smoothed down?

 

[BrApple]

the main cat is more then enough for this car ....


gutting the pre-cats .... break the material out of the manifold ...

 

[KAOS_3.0]

I know what gutting them is, I was just saying, people do modify the manifolds.

and like I was also saying, it may be just enough to pass emissions, but they put the pre-cats there for a reason.

anybody tried to pass something like CA emissions with headers and mil eliminators?

 

[95pgt-t]

yes,and most can do it

 

[hetfield]

and like I was also saying, it may be just enough to pass emissions, but they put the pre-cats there for a reason.

Yes, mostly to lower emissions before the main cat heats up, which is within minutes. Once the main is heated up the pre-cats do very little.

yeah, I sort of enjoy passing emissions and not destroying the earth.

Catalytic converts change carbon monoxide to carbon dioxide (among other things). CO2 is what currently is destroying the earth, according to the People's Republic of California. With how clean and efficient most engines are these days you may be helping the earth be removing your cats, but you'd be poisoning the inhabitants.

 

[Harrry]

yeah, I sort of enjoy passing emissions and not destroying the earth.?

ROFLMAO geez....Destroying the earth. Maybe you guys sue 89% of the world for not having emission testing on their cars.:help:

 

[KAOS_3.0]

Yes, mostly to lower emissions before the main cat heats up, which is within minutes. Once the main is heated up the pre-cats do very little.

interesting, I thought they were there so the car could better determine it's own emissions via the downstream o2's.

Catalytic converts change carbon monoxide to carbon dioxide (among other things). CO2 is what currently is destroying the earth, according to the People's Republic of California. With how clean and efficient most engines are these days you may be helping the earth be removing your cats, but you'd be poisoning the inhabitants.

that contradicts itself a little doesn't it? by "killing the earth" I wasn't really talking about global warming, i was talking about killing everything on the earth. the earth is a big rock. you cant really kill a rock. well I know one guy that can, but none of his cars work.

 

[Blackcoog]

Nope, precats as stated are only there for initial warm up. After warm up the main cat takes over. Most past testing as long as they aren't visually failed for just having the headers installed.

 

[KAOS_3.0]

ahh, well when I've got the money, I'll probably throw a set on then.

 

[hetfield]

interesting, I thought they were there so the car could better determine it's own emissions via the downstream o2's.

No, they'd just relocate the O2 sensors to the main cat, like on many other cars.

 

[KAOS_3.0]

uh, for some reason, the way you said that is confusing, like it's way out of context, a little clearer?

relocating the 02's is a novel idea though

 

[michcougar]

No, they'd just relocate the O2 sensors to the main cat, like on many other cars.

You dont relocate anything. You would just put a MIL on the 2 lower o2's.

 

[KAOS_3.0]

I sot of like the idea of relocating them

 

[morbid]

The late model Cougars have 3 cat checking o2's. Two where ours are, and another after the primary cat. Since the preliminary cats kind of function differently (or have a different function) than the primary cat, I'm not sure if the readings for a post-primary cat o2 would be the same as the post-worthless cats.

 

[BrApple]

The late model Cougars have 3 cat checking o2's. Two where ours are, and another after the primary cat. Since the preliminary cats kind of function differently (or have a different function) than the primary cat, I'm not sure if the readings for a post-primary cat o2 would be the same as the post-worthless cats.

I thought that they had three O2 sensors in the exhaust. two before the precats and one after the main cat. this is why they don't need mil-eliminators with headers.

 

[Rara]

Downstream O2s are a result of the OBD-II diagnositc requirements, and are simply there to verify that the originally installed cats are still functioning. The upstream O2s are what the PCM uses to adjust fuel delivery.

 

[KAOS_3.0]

we could cut the manifolds up and run 6 side pipes, that would batmobiletastic

 

[morbid]

I thought that they had three O2 sensors in the exhaust. two before the precats and one after the main cat. this is why they don't need mil-eliminators with headers.

Ah... I knew for sure that they added the one after the main cat, I guess I assumed the other 2 were retained. I'm running a Trubendz Cougar cat pipe and had to plug that bung.