1978 L82 exhaust choices

[Mark P.]

My 78 will be in need of a new exhaust system soon
I am trying to research what may be good. The car will not be shown but driven for fun as it should be. We live in Florida
Does anyone have any advice about putting in a real dual system vs stock system. I don't want to change the headers but could if there is an advantage.

Really just a nice performance dual system would be great, I think!

Any suggestions would be great
Thanks

[Joe L.]

Re: 1978 L82 exhaust choices

My 78 will be in need of a new exhaust system soon
I am trying to research what may be good. The car will not be shown but driven for fun as it should be. We live in Florida
Does anyone have any advice about putting in a real dual system vs stock system. I don't want to change the headers but could if there is an advantage.

Really just a nice performance dual system would be great, I think!

Any suggestions would be great
Thanks

Mark------


Do you have emission inspections in Florida, now or in the future? If so, I would not recommend going to a true dual exhaust system and, consequently, eliminating the catalytic converter. Whether, or not, you have inspections, removal of the converter is a violation of federal law. It will also make it more difficult to sell the car someday to a buyer in an emission-inspection area.

[Michael D.]

Re: 1978 L82 exhaust choices

Hop on to the other Corvette Forums. The true dual installation has been done by hundreds of folks. A search of the archived threads is likely to turn up everything you want to know.

[Steven B.]

Re: 1978 L82 exhaust choices

For autocrossing I first installed a '74 system with Walker Turbo mufflers (low back pressure) on my L-82 and later went up in class with headers. Instead of the '74 system I could have saved $$ and just had a muffler shop bend pipes.

Steve

[Duke W.]

Re: 1978 L82 exhaust choices

Removing emission control devices is a violation of federal and some state's laws; however, if the state does not have an inspection program, it is unlikely you will ever be "caught". The FBI is not running around looking under old cars.

In addition, most states have special "historical" plates for cars at least 25 years old, which may also eliminate them from normal state emissions inspections. This doesn't mean altering the emission control system is legal. It just means you are unlikely to get caught and have to restore everything to OE configuration.

Per Dave McClellan's book the single catalyst exhaust system increased exhaust system back pressure by "half and atmosphere", which is HUGH!!!

The resultant loss of both flywheel and rear wheel power was substantial.

With a full dual exhaust system and an optimized pre-emission spark advance map, it will feel like like a completely different car. Headers are neither necessary nor desirable. They add little power to a car with mufflers and often have significant installation and operational problems.

You should get a chassis dyno test, make the changes, then retest if you want to quantify the difference.

Of course, keep all the old parts in case you or someone else for any reason wants to revert back to the OE exhaust system and spark advance map.

Some have installed dual exhaust systems with converters on each side thinking they are "legal". They are NOT, because altering the emission control system in any way is illegal unless the car is recertified to EPA standards by a licensed emission control lab. This is true even if measured engine emissions are less than state test cut points. It should fail the "visual inspection" due to the change of catalyst configuration, however, unless the emission test tech looks up the car in his reference books to see the catalyst configuration it will likely pass, as most emission control techs were not born when your car was built, and they have likely never seen an early emission controlled Corvette configuration.

Duke

[Michael W.]

Re: 1978 L82 exhaust choices

Mark,

If local emission laws are not a concern, check out Corvette Central's systems. The '74 system would fit your '78.

[Mark P.]

Re: 1978 L82 exhaust choices

Thanks for all the advice the question appears to be will I move to .
CA if so do the cat!

[Joe L.]

Re: 1978 L82 exhaust choices

Thanks for all the advice the question appears to be will I move to .
CA if so do the cat!

Mark-----


Not just California. Many other states have emissions inspection programs.