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Any Exhaust Experts Here?

Aussie67

Aussie67

Well-Known Member
Looking for some help/ comments on fitting cat converters to my 67. Obviously the car runs on unleaded and the fumes are over whelming/ toxic. I can't stay in the shed with the car running for longer than 10mins.

The exhaust is a standard 2 inch, and while I don't know much about cat converters, I'm guessing the effectiveness is dependant on operating temp?

Anyone already done this, and if so what was the result? Which cat did you fit?

Tony
 
Aussie67 said:
Looking for some help/ comments on fitting cat converters to my 67. Obviously the car runs on unleaded and the fumes are over whelming/ toxic. I can't stay in the shed with the car running for longer than 10mins.

The exhaust is a standard 2 inch, and while I don't know much about cat converters, I'm guessing the effectiveness is dependant on operating temp?

Anyone already done this, and if so what was the result? Which cat did you fit?

Tony
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I would never run them. I understand why you want to but I would never add restriction to my exhaust. In fact I like straight pipes no mufflers, nothing.

On my 67 I have turbo mufflers and when running in the garage I make sure to have a window and the man door open as well as the bay door. Gets great ventilation.

I would say the answer is adequate ventilation not restricting your cars exhaust.

Just my .02

Mel

Sent from my Pixel 2 using Tapatalk
 
The tuning is ok, its just that the fuel additives such as benzene and methyl tertiary butyl don't get fully "burnt off".

Guess its a open window then.
 
Aussie67 said:
The tuning is ok, its just that the fuel additives such as benzene and methyl tertiary butyl don't get fully "burnt off".

Guess its a open window then.
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If they aren't being burned you are running rich.

Mel

Sent from my Pixel 2 using Tapatalk
 
^ what that guy said.

You absolutely do not want to run cats on a car not designed for it. Engines that are designed for cats do some complicated things to the fuel mixture to keep the cats from burning up or clogging up.

If you have a really noxious exhaust smell under hot idle conditions, you're likely running too rich. Just because the car runs OK doesn't mean it's tuned properly. It really helps to tune it with a wideband O2 sensor. At the very least a vacuum gauge.

Also, keep in mind that a lopey cam will be very difficult to dial in at idle. There will almost always be a bunch of unburned fuel coming out the pipes.
 
Are CATs required by law there?

A tune and a decent muffler...(Magnaflow, Flowmaster) should be fine.
 
Thanks, I'll recheck the tune.

No we aren't required to run the cats here for this year of vehicle. I take the point about without the ECU, the cat is probably going to fouled up quickly, so I guess it's stay with plan A (tune).

Tony
 
guruatbol said:
I would never run them. I understand why you want to but I would never add restriction to my exhaust. In fact I like straight pipes no mufflers, nothing.
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Mel. I installed 2" electric cutouts on my '69 convertible about two years ago. They are controllable from the driver's seat using either a remote or a toggle switch under the dash. They're located just behind the collectors for my tri-Ys. With them babies cracked open it's like the end of the world is coming any minute. One of my buddies described them as "rude". I don't think he likes them.:eek: Love the sound of the cam coming through loud and clear. Much easier than my old manual setup since I can't get down to get under the car anymore and I can shut them off with the push of a button when The Man shows up.
 
Aussie67 said:
Just a follow up on this.

http://www.redbackconverters.com/classic-car-catalytic-converter/

I'm going to give them a try. Can always take them off if they don't work.
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Sounds like you lay awake nights worrying about the environment like Alexandria Ocasio-Cortez. I have electric cutouts on my '09 Corvette and they sound like crap. There are two cats on each side of the duals and the cutouts are behind them. They provide so much restriction that they muffle the engine sound. Same thing was true of my '00 Camaro Z28. It only had two cats but it didn't sound anything like an open exhaust. Just don't run your car in a closed area. I have to agree that if the fumes are that noxious you are probably running too fat but you shouldn't be sitting in a closed garage with the engine running unless your are contemplating something besides a tune up.
 
RagTop said:
Sounds like you lay awake nights worrying about the environment like Alexandria Ocasio-Cortez.
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No not quite. My other toy is a 450RWHP Monaro, or GTO in the US and the exhaust note rattles the window glass no problem. The issue I'm chasing is the almost chemical smell/ fumes. The fuel quality in Oz is pretty crap, so I'm guessing the fuel has a lot more additives than elsewhere.

The car is usually parked about 10m from the back door of the house and it still sets the smoke alarm off. While I have managed to reduce It slightly through the tune, the cats I'm looking at (not cutouts) seem to have good results on the dyno, so I'm not too worried about restrictions. Can always take them off if they don't work/ do much.

Anyway, all good, so can close the thread.
 

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RagTop said:
Mel. I installed 2" electric cutouts on my '69 convertible about two years ago. They are controllable from the driver's seat using either a remote or a toggle switch under the dash. They're located just behind the collectors for my tri-Ys. With them babies cracked open it's like the end of the world is coming any minute. One of my buddies described them as "rude". I don't think he likes them.:eek: Love the sound of the cam coming through loud and clear. Much easier than my old manual setup since I can't get down to get under the car anymore and I can shut them off with the push of a button when The Man shows up.
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Oh I've got to hijack this thread with lots of questions- whose did you use?, do they need periodic maintenance or are they trouble free? do you just dump them under the car or pipe them to the side?, do they seal up good when off?
 
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