83 airbox question

nineball · 10-13-2009, 05:49 PM

Please pardon my non-techincal jargon as I am still learning the ins and outs of my new toy.

I recently found out my airbox had blown and purchased a NOS from another member. The part number was the same as the Pelican site listed. My mechanic looked at it and told me that while it is usable it is an older version that is missing a rail (?) on the inside. If you are looking at the box as it sits on the engine the missing rail would run from the rear left side (inside the smallest opening on top) to the front of the box where it splits into 3 pieces.

Can anyone confirm or deny this, or even shed a little more light on it? Is it possible the mechanic is confusing something based on model year?

80-911SC · 80-911SC's Garage

pictures would help ...

nineball · 10-13-2009, 09:27 PM

This shows what I am talking about. The missing rail enters from the top of the pic and then splits into 3 below.

tuned6 · 12:03 AM

Your mechanic is right. You don't want to use this box with your setup.
The box with the rail is the updated airbox. I believe they started them in '81? It was for the cold start valve and aux air to enter and mix through during cold start conditions. The rail was supposed to help prevent blown air boxes caused by backfires by keeping the fuel atomized and directing it's aim while the cold start valve was on.

If you had an earlier car, I believe 2.7 and prior, you'd have a hand throttle next to the e-brake which was deleted with the introduction of the 'automatic' aux air valve. The box that you have is for the non aux. air valve system.

I don't know if you could add the rail and air inlet from your blown box?
Since you are paying someone else to do the work it would probably be worth picking up a used air box with the rail and do it right. I just saw a complete setup in the classifieds for $200 from an '81.
Make sure you use a pop-off valve which will relieve pressure when you do backfire. If you ever have your car stall out after a backfire with the pop-off valve installed check to see that the valve isn't hung open on your air filter and failing to reset.
Hope that helps.
Good luck.
Christopher

stlrj · 10-13-2009, 11:51 PM

I would not install an air box without the internal cold start plumbing. In most cases, it eliminates air box explosions entirely without the need of a flapper valve.

Unfortunately, there is no way to retrofit the rail into an earlier box.

Joe

nineball · 10-14-2009, 06:13 AM

Thanks for the replies. If this is the case why is Pelican still selling the airbox without the rails? You would think they would have upgraded as well. Looks like I am parts searching again.