chrome bumpers & emission controls

[BillyBob]

OK, Ernie R2 R5388 was a Big Help on chrome-bumper stick shifts - - thanks!

Let me try another, please . . .

I seem to recall '73 as The Year of the Catalytic Converter. What are good & bad years for chrome-bumper IIs with emission controls?

In Ernie's response to "chrome-bumper stick shifts" he mentioned "early IIs" as high quality. What years are considerd early IIs & high quality in what respect?

[ernier]

1975 most of the industry went to cats. Some Mopars got away with it for a couple more model years. I'll leave the rest of the question to the Avanti II guys.

Ernie R2 R5388

OK, Ernie R2 R5388 was a Big Help on chrome-bumper stick shifts - - thanks!

Let me try another, please . . .

I seem to recall '73 as The Year of the Catalytic Converter. What are good & bad years for chrome-bumper IIs with emission controls?

In Ernie's response to "chrome-bumper stick shifts" he mentioned "early IIs" as high quality. What years are considerd early IIs & high quality in what respect?

[Gunslinger]

1975 most of the industry went to cats. Some Mopars got away with it for a couple more model years. I'll leave the rest of the question to the Avanti II guys.

Ernie R2 R5388

As far as decreased performance regarding Avanti's, it's more accurate to say all cars of the emissions era suffered from reduced performance. The manufacturers were pretty much concentrating on reducing emissions and increased safety standards (bumpers, etc.), as well as trying to increase fuel economy and performance was secondary at best. I would put that time period as starting around '71-'73 and really hitting bottom about '75-'77. After that period the manufacturers were still on the learning curve of increasing performance again, or at least stopping the decline.

If there is an era where Avanti performance began to suffer, it was probably when the 350 Vette engine was changed in favor of the 400 cubic inch sedan engine with a two barrel carburetor. I don't know the reason for the switch...maybe it was availability issues with GM, maybe emissions issues, maybe it was cost...I certainly don't have a clue. I understand the 400 had some definite driveability issues, particularly at take-off, during that era. Things apparently got worse when the 400 was switched to the 305 later in the '70s. Not that there were anything inherently wrong with the engines...the small block Chevy is one of the outstanding engines of all time, but it was a combination of reduced compression ratio, emissions equipment robbing the power even more, increased weight of the car as more and more mandated equipment was added, and the restrictive exhaust system necessary.

As far as Avanti quality, I've read where the quality began to decline after Nate Altman died in '76. Even though his brother took his place and the people involved loved the car, without Nate's force of personality the company began to drift and quality allegedly suffered. I've also read where they ran out of original Avanti and Lark convertible frames and adapted Stude frames that were thinner guage steel and less strong, plus had been sitting out in the weather for years. Supposedly this occured for the last half of the '70s.

Supposedly, after Steve Blake bought the company around '83-'84 the quality control went up again...at least until the paint debacle which helped throw the company into bankruptcy.

A lot of the alleged problems really don't mean a lot now...I would think that either the cars have been updated and restored or they've been parted out or waiting to be parted out.

[SBCA96]

If you have an Avanti II that requires a CAT, see if your local laws let you

ditch the "bb" pellet CATS and use a newer ceramic honeycomb CAT. Its

a LOT better for performace, usually only causing a 2 hp decrease per CAT.

Tom

[IndyJimW]

If you have an Avanti II that requires a CAT, see if your local laws let you

ditch the "bb" pellet CATS and use a newer ceramic honeycomb CAT. Its

a LOT better for performace, usually only causing a 2 hp decrease per CAT.

Tom

Good idea but make sure you have the correct type of CAT for what the OEM manufacturer is trying to accomplish. An example would be back in the 70’s you wouldn’t want to see water coming out of the exhaust, that’s bad. Today you want to see water coming out of the exhaust, that’s good. Different CATS for different results.

Jim Wood

[Kellerbear]

I'm negotiating for a nice 1978 Avanti II. The owner removed the catalytic converter and replaced with a 1973 Avanti exhaust system. He says he never had trouble getting it inspected and they don't do emissions testing in Texas for cars that old. Anything I ought to consider on this?

[ernier]

the worst that could happen is you have to replace the improper system with one that will pass your sta e inspection. in nj anything that is 25+ years old can be registered historic and not have to go through any inspection. it wouldn't keep mr from buying the car.

Ernie R2 R5388

I'm negotiating for a nice 1978 Avanti II. The owner removed the catalytic converter and replaced with a 1973 Avanti exhaust system. He says he never had trouble getting it inspected and they don't do emissions testing in Texas for cars that old. Anything I ought to consider on this?