I've been trying to search, but noone seems to really cover this. I've got an '88 Bird with TBI at the moment, switching over to an '87 MAF 305 motor, and have an '86 bird air box, of which except for the rubber ducting attatching to the plenum looks identical, so i figured to save a little money, i would use it for the time being, since i'm not sure if i want to go SD yet. Now looking more into it, did they change the intake box setup to look better in '88 or was it due to the serpentine setup? It looks like the air box i have should work, but i don't want to rebuild the motor, put everything together, get the motor in the car and find out i gotta run around chasing down parts for a month. I want everything ready to drop and go when the time comes. Anyone that has possibly ever tried this and failed, succeeded, or if there is anyone able to try and make the comparisons for me that would be great. I haven't been able to mock up the setup in my firebird yet, but either way, the correct motor that i'm dropping in isn't there so there is no guarantee either way. Specs are '88 TBI car, complete '87 TPI motor soon to have serpentine accesories, '86 v6 air box setup and hosing, with the camaro tpi plenum to air box tubing adapter inplace of the v6 plenum to tubing adapter. What do you think?

After reading the above, was i confusing? Or is it just an unknown topic. Just want to make it clear if it wasn't so that i can get to the bottom of this dilemma. Thanks!

Jon

The Firebird TPI intake ducting changed 3 times. The first was used from 85-87 and has a short rubber bellows to a plastic chamber, then the MAF sensor comes off of the chamber and connects to the side of the airfilter canister. The canister is round, with a square cover on the top. Air is pulled through the top of the canister into the center of the filter, out the side of the canister, etc. It's restrictive, leaky, and looks silly.


In 88 the system was massively improved. The new system had a large 90* rubber bellows that connects directly to the MAF, then there's another rubber bellows that runs from the MAF to the top of the filter canister. Air comes in from the side of the filter, is pulled from the center, and into the engine. The change is huge, it flows much better and it doesnt have nearly as many places it can leak air past the filter or MAF. If you're running MAF and your car isn't a show car, this is the setup you want.


Then in 90 it changed again for speed density. The canister is identical to 88-89, as is the filter and lid. Instead of the rubber bellows, there's a molded plastic duct that runs from the filter canister to a short rubber bellows that connects to the throttle body. This system is probably the least restrictive of the bunch.


To the best of my knowledge, none of these changes were to clear serpentine accessories. If you need a MAF and want the best system available, get a 88-89 intake duct. I wouldn't use the 6cyl, 85-87 system unless it's really your only option. You'll probably drop half a second switching from that to anything else.

Alright, well i figured that if i found it in the junk yard, i'd definally switch, but for the time being, possesion is 9/10ths of the law, and i have the 6 cylinder setup, which is identical to the v8 setup except for the bellow that connects the tubing to the throttle body, of which i have the short piece off of a MAF camaro to solve that problem. I just wanted to make sure i wouldn't end up running into an issue with the serpentine system, of which seems odd that the air box and belt system changed in the same year, which made me concerned for my install. Like i said, for the time being, i don't mind the 85-87 design, while i agree completely with all the problems you said with the setup, i will work my way to the '88-89 setup for a period correct setup in my '88 bird plus the improvements along the way. Good to know that the 88-92 air box was the same, so i can start looking at v6 90-92 birds and camaros too. Thanks!