On my recently aquired 85 GSL (12a), while re-doing the vacuum lines i found this nipple on the Right side of the engine under the carburetor. From the looks of it, it has not been hooked up to anything in some time. What is it? and what is supposed to be hooked up to it? (See Pic)

Thanks!

-Steve

 

All that crap is gone from my car, but I think that's supposed to connect to a hose that runs air back to the catalytic converter. Go over to mazspeed.com and look at the emissions removal tutorial in the Facts section.

 

Yep,thats the split air pipe to feed air to the precats.
The bigger tube to the rear is the main air pipe to the primary cat.

Nice exhaust ports,looks like a healthy engine......

 

Thanks for the replies. Im not sure the history of this car. Its is an 85 gsl, but the engine has the oil cooler in front of the radiator instead of the honeycomb style, which I understand, is not typical (but better). My 83 GS doesnt appear to have but one 'pipe' going from the cat back to the engine, thus doesnt have the hookup pictured above. Since I am replacing the Catalytic converter with a Racing Beat straight piece, which has just one connection (the larger one). Wonder what I should do with this connection?

-Steve

 

The name of the mushroom shaped metal thingy it's coming out of is the "#2 Anti Afterburn Valve" (or AAB#2)

It's useless if you don't care about emissions, and since you're replacing the cat with a straight pipe (which will be forkin' loud btw, you'd be best to go with a full RB system with presilencer and muffler), I'm assuming you don't.

Jon

 

No, Sound is not a major concern. Its going to be a spec RX7 race car when its FINALLY finished. Eventually want to replace everything from the exhaust manifold back, but don't have the budget for that right now. THanks for the info.

-Steve