Bought his 91 RS a few weeks ago. This is my first 3rd gen and really first project car in general. I was going over the engine bay and it's filthy! Then I saw the air cleaner and noticed that it looks like the top was removed and replaced with what looks like an open element filter... The strange part is, the snorkel is still attached(which wouldn't be doing much), and the PCV hose is still attached to the outer wall of the original system and venting basically into the engine bay which is probably why it's so dirty.

Is the way its running now a problem? Or should I buy an oem style top and filter asap?

 

Previous owner was a moron. The only way that system works well is if there's some sort of "hood" air intake--"cowl induction" or similar. Then the hood and associated components act as part of the air cleaner housing. But you didn't mention anything special in terms of the hood.

Find a proper lid. It won't make as much noise, but it's likely to actually work better.

 

it does have a monstrous cowl hood. That might explain it. So basically the lid is off so it can intake from the cowl. Sorry I’m new to this stuff. Thanks for mentioning the cowl, I wouldn’t have considered that to be a factor otherwise!

 

A "real" cowl-induction hood is SEALED to the air cleaner, so the ambient air can't bleed out and fill the entire engine compartment. GM sealed all their "hood air" vehicles, including Chevy Cowl Induction, Pontiac Shakers, Olds OAI, and whatever Buick called their system. They were sealed with rubber strips, or with foam. The "cold" outside air was reserved for the carburetor.

Same for Chrysler, same for Ford.

But when it's a cheap aftermarket hood installed by a Bozo, the "cold" air bleeds all over the engine compartment, has no proper drainage of rainwater, and interferes with the hot air coming through the radiator.

 

I'm guessing the guy lost his air cleaner lid and bought the first/only similar lid at the bone-yard he could find so he had something there. The best thing about it,.. your only taking in filtered air; the worst part about it is that your not water tight.

For a temporary solution you can use an 80's GM 350 truck air cleaner lid,....... it's a little taller than a Thirdgen air cleaner lid and allows for a larger than factory filter. At that point your getting cold air again, and the air cleaner can't get water in it so you can take your time to decide on sumthin' more permanent.



P.S. Welcome to TGO !!

 

I would not want to try to look around that tall cowl . But it's a good looking car , welcome to the thirdgen world!

 

I already have neck pain from driving it around. I like the look, and the paint + stripes are very nice so I'm trying to learn to love it.

 

I think that the stock air filter is the restriction. Using an open element lid will help or one with the taller filter as used in the 75 Corvette or a bunch of other GM cars. It is the same diameter and 3.5" tall instead of 2.5" and fits under the hood. You will notice a difference compared to these so called cold air mods.

 

You can "think" that the stock air filter is a restriction, or you can TEST and VERIFY.

The Treasure Yards have plenty of air filter restriction indicators. They're sold on eBay and Amazon, and your local NAPA, O'Reillys, Autozone, etc. Plumb one into the clean side of the air cleaner housing, and "go for a drive".

If you aren't triggering the restriction indicator at max RPM/WFO (highest air flow demand) you don't have a restriction at the filter.

 

It was with mine. I don't need a science test to confirm that, a throttle test was good enough for me. Those stock air filters are a restriction. Heck everything on a stock 305 is a restriction. Cold air won't improve your throttle response, more air will. So get more air in and you and your right foot will be happy!

 

Yep, those same restriction gauges say a paper element is not restrictive too, but I will trust my MAP sensor over it.

 

I'd be fine taking data from the MAP sensor...although the MAP sensor is also measuring the restriction of the throttle body and the whole intake system down to the manifold plenum, rather than just the air cleaner and back to the atmosphere.

My point all along was to use actual DATA, not a "guess" or "I think...".

 

Get an open element air cleaner and be done with it. Looks better

 

LOL. This stuff is rich. "AH don't need no science to tell me mah motah is loudah....ah mean, fastah, now!"

Schurkey is right; measure. You should at least upgrade your "measuring" tools, to include the #1 HP measuring tool of the ignorant: The 1-wheel-peel-0-meter!

 

Oh boy, being belittled by the supreme members. What's a poor little novice boy to do? I'll go along with what DMCCAIN said and put a 14" open air cleaner in it and if that doesn't fix it, I guess I'll put a 301 Turbo in it! I'll report back as to whether my right foot liked it or not . . .

 

LOL...month and a half later. Should I apologize for being a "Supreme Member"? Not sure what I can do about that...the status accrued by itself, so....

Go for it. Do whatever you want to. Never said otherwise or anything close to otherwise. What *I* said, was in response to this brilliant gem of...."advice":
It's fine that you like your open air filter...in fact it's great, that you like it! Love the wee out of the thing. But don't give worthless advice about it, using your "throttle test"...then argue about it to boot! Geezus.


Good luck w/a 301T. Love to hear how that turns out. Get a dyno reading of the thing when you're done...would you?

 

OMG if you pissed him off just think what would have happened if Sofa had replied to his thread. LoL We would have to give him the number to the Suicide Prevention Hotline.

 

When you drive a 5.0L TBI, automatic slush box, 2.73 geared lame azz cars like the OP and I have empirical data isn't really necessary. We get gapped by 10 car lengths in a 1/4 mile by a soccer mom in her mini-van full of rug rats.

Butt dyno and my feelings is all that matter.

Will it put on a smoke show if power braked? Yes

Will is bark the tire if flat punched from a dead stop? Yes

Will it chirp the tires on the 1 to 2 upshift? Yes

Does it make a nice air induction roar from the mighty L03 with the stock air cleaner lid on top of an inch taller TBI truck air filter? Yes

If it can do that it's all that matters because that junk ain't ever going to be fast. Soccer mom still smoking us.

 

Very true. Well said.

 

There's a whole lotta contentious clucking further down the thread. Until we can quantify what sounds cool or looks badass maybe the faq about tbi open element will help you out.
https://www.thirdgen.org/techbb2/sho...hreadid=171757