OEM Air Injection, Yay or nay?

[Dane-ger]

Catalytic Converters Require fresh air to work efficiently.

Sorry...I had a brain fart. Yes...there needs to be oxygen present so that the HC's can be converted into CO2. The cat doesn't provide the oxygen, just catylyzes the reaction.

So does this mean that all catylytic converter equipped cars have some form of air pump? I can't remember many later model cars (80's and newer) with air injection tubes sticking into the exhaust.

THEN, If you need to add a cat. get one with a feed pipe and use an electric pump. (for the weight savings)

Oooooh...it pumps air directly to the converter?

The new electric air pumps use Very Little current.
(My daughters Jetta has one and I can not even measure its draw with my antique amp meter)

Wow...I'll need to look into those then.

Great...sounds like you have a handle on it!

(Hard to tell from your initial post how much you knew about the details of the car -- didn't mean to tell you stuff you already knew. )

I've been playing/struggling with this thing for far too many years now...have gotten a lot done but still have a long ways to go in getting it the way I want it.

Still, you have chosen a car with a massive overbite and attendant drag 'shute front end. Good thing they're such handsome cars, eh?

Yeah...I fell in love with 240Z's long before I had a good understanding of their aerodynamics...what can I say? By the way...what kind of mileage does the 510 get?

Of course, I offer this with the presumption that you are interested in maintaining the car emissions legal. I understand your next check is in 4 years, but I see little down side to maintaining low emissions while working to improve your car's FE.

The Z is a '71...and considering all the different engines that people swap into these things (SBC's, various turbo motors, etc)...I'm not even sure if I legally "need" to keep the air injection hardware just so long as it passes the tailpipe test. I've seen lots of 240Z engine bays without air injection...seems hard to believe that they are all illegal. Hell...all the commercially available headers do away with it completely.

[metroschultz]

Man are we discussing this thing to death or what.
The vehicles that have no air pump rely on usable oxygen from the exhaust itself. When you release the throttle there is a low pressure wave in the pipes and free oxygen pumped through the combustion chamber is drawn into the cat to assist the burn. To this end some of the vehicles (big 8 Chrysler products come to mind) use a one way check valve ported to the breather and directed to the cat.

I said it once, I say again. Go cat free and re-test your emissions.

1971 was a good year to be a car.
cats were not required and the emissions test was more lenient.
btw I checked with Va State Police who stated "If your car is registered as a 1971 vehicle it has to meet 1971 standards."
This is supposed to be the case in all 50 states, the territories, and D.C.
Good Morning, S.