75 roadster exhaust judging

[Ross F.]

Ok. I gave a 75 roadster L48.
It came with an AIR, Cat, and 2-1-2 exhaust. Actually they all did. My question.....Baring perfectly original AIR, exhaust, and cat,
what is the least offense option judging wise.
The 75 are the worst performing corvettes ever. And original functional cats are non existent. Who'd want one anyway.
So.....
I first installed the AIR system as original with the single air pipe attached to the right side exhaust below the manifold. And an aftermarket 2-1-2 exhaust with a high flow Cat. Probably most correct. I hated it.
Next I pulled everything off. 75 exhaust manifolds have on ports to plug, no pump. No pulley. No hoses. Removed mounting studs. Full dual exhaust. Ok. So. It looked naked. My guess most offensive.
I now have the 74 set up. kinda..
correct 75 ported manifolds. Yes they are out there. Due most likely to a early production change. Original 74 bagpipes and diverter valve. 75 pump. And dual exhausts.. the kinda is I'm using the 75 vacuum operated EFE instead of the mechanical 74 version. I like this set up.

Ok judges how bad is it? ?

[Edward J.]

Re: 75 roadster exhaust judging

Ross, the best way to approach the judging point deducts would be print up the mechanical judging sheets and take the line items involved and deduct all the originality and condition points for anything that was removed or missing.there maybe a few other items that will see some partial deducts such as vacuum hoses that are removed plugged themo vacuum switch? Don't forget exhaust manifold if you changed out.

[Ross F.]

Re: 75 roadster exhaust judging

I' m still using all hoses, switches, and valves.
just trying to take the least point deduction and keep my dual exhausts

[Joe L.]

Re: 75 roadster exhaust judging

Ok. I gave a 75 roadster L48.
It came with an AIR, Cat, and 2-1-2 exhaust. Actually they all did. My question.....Baring perfectly original AIR, exhaust, and cat,
what is the least offense option judging wise.
The 75 are the worst performing corvettes ever. And original functional cats are non existent. Who'd want one anyway.
So.....
I first installed the AIR system as original with the single air pipe attached to the right side exhaust below the manifold. And an aftermarket 2-1-2 exhaust with a high flow Cat. Probably most correct. I hated it.
Next I pulled everything off. 75 exhaust manifolds have on ports to plug, no pump. No pulley. No hoses. Removed mounting studs. Full dual exhaust. Ok. So. It looked naked. My guess most offensive.
I now have the 74 set up. kinda..
correct 75 ported manifolds. Yes they are out there. Due most likely to a early production change. Original 74 bagpipes and diverter valve. 75 pump. And dual exhausts.. the kinda is I'm using the 75 vacuum operated EFE instead of the mechanical 74 version. I like this set up.

Ok judges how bad is it? ?

Ross------


One thing to keep in mind: it's against federal law to remove a catalytic converter or, for that matter, an AIR system from a car originally so-equipped. That law is unlikely to be enforced in an area of a state which does not require smog checks. However, while the liklihood of federal detection is small, the fines are very large. For states with smog check programs, a missing catalytic converter or AIR system is an automatic fail.
Also, it is not legal to add dual catalytic converters to any car originally equipped with a single converter.

You are correct that the original bead-type converter, GM #8998109, is extremely difficult to find and a very problematic piece in any event. However, a direct fit, monolithic type converter is available in the aftermarket.

[Ross F.]

Re: 75 roadster exhaust judging

That's a conversation stopper!
Joe, I have a vague understanding of those regulations. As I purchased this car from a licensed dealer in this condition. I.e. no CAT. The original removal purp is in violation of the act.
Not the dealer or I.
I'm just trying to make the best of the situation.

[Michael W.]

Re: 75 roadster exhaust judging

Best is to reinstall the original AIR system. The performance impact of any such system is negligible, in the order of maybe 1 HP. This helps on the judging aspect.

For the exhaust, a 2-1-2 system with a modern high flow converter will have minimal impact on performance. This makes you 'legal' and in a decent position for judging.

[Joe L.]

Re: 75 roadster exhaust judging

That's a conversation stopper!
Joe, I have a vague understanding of those regulations. As I purchased this car from a licensed dealer in this condition. I.e. no CAT. The original removal purp is in violation of the act.
Not the dealer or I.
I'm just trying to make the best of the situation.

Ross-----


It doesn't work that way. The current registered owner of the car is the one that will be held responsible for emissions violations. As far as the law is concerned, you're the one that possesses and is operating the car in an emission-illegal configuration. Of course, you might have a civil action against the dealer that sold you an emissions-illegal car.

[Tom R.]

Re: 75 roadster exhaust judging

Best is to reinstall the original AIR system. The performance impact of any such system is negligible, in the order of maybe 1 HP. This helps on the judging aspect.

For the exhaust, a 2-1-2 carbon steel system with a modern high flow converter will have minimal impact on performance. This makes you 'legal' and in a decent position for judging.

And that system should be carbon steel versus aluminum or stainless steel.

[Ross F.]

Re: 75 roadster exhaust judging

I hate to beat a dead horse. But federal law has no provision for prosecution of an owner of a car that he purchased with "tampered"emissions equipment.
Now if it can be proven the owner tampered with the equipment, that's different. And there may be state laws that apply.

[Rich C.]

Re: 75 roadster exhaust judging

Don't some states exempt pollution controls on 25+ year old cars? Or is that wishful thinking!

1973 LS-4 454 coupe owned 24 years
1996 LT-4 CE coupe owned 17 months
Sierra Nevada Celebration Ale currently on tap!

[Ross F.]

Re: 75 roadster exhaust judging

Rich,
From the research I've done on the topic.
the answer to your question is yes.
25 years was a time limit. But now that would mean 1990, well into computers and fuel injection.
many have dates and 1975 and earlier is fairly common.
The exceptions are California and New York. They are very strict.

[Joe L.]

Re: 75 roadster exhaust judging

Don't some states exempt pollution controls on 25+ year old cars? Or is that wishful thinking!

1973 LS-4 454 coupe owned 24 years
1996 LT-4 CE coupe owned 17 months
Sierra Nevada Celebration Ale currently on tap!

Rich------

There is a big misconception on this, at least for California. California exempts 1975 and earlier cars from the requirement for bi-annual smog inspections. It absolutely does not exempt cars from the requirement that no smog control components be removed or otherwise tampered with. It remains against California and Federal law to do that. In addition, there remain tailpipe standards for all 1966-75 cars in California. If a car is identified by remote roadside testing equipment as a "gross polluter", that car owner will be notified and directed to a "referee station" for emissions control system inspection and tailpipe emissions testing.

[Joe L.]

Re: 75 roadster exhaust judging

I hate to beat a dead horse. But federal law has no provision for prosecution of an owner of a car that he purchased with "tampered"emissions equipment.
Now if it can be proven the owner tampered with the equipment, that's different. And there may be state laws that apply.

Ross------


So, what you're saying is that if one is caught with a car with a tampered emissions control system all one has to do is say that someone else did it and that makes everything OK?

[Terry M.]

Re: 75 roadster exhaust judging

Rich------

There is a big misconception on this, at least for California. California exempts 1975 and earlier cars from the requirement for bi-annual smog inspections. It absolutely does not exempt cars from the requirement that no smog control components be removed or otherwise tampered with. It remains against California and Federal law to do that. In addition, there remain tailpipe standards for all 1966-75 cars in California. If a car is identified by remote roadside testing equipment as a "gross polluter", that car owner will be notified and directed to a "referee station" for emissions control system inspection and tailpipe emissions testing.

Joe,
State laws are widely different on testing requirements.
In Illinois only vehicles registered in certain counties (read the large metropolitan areas) are required to be tested. No vehicle with antique tags (25 or more years old) is required to have a pollution test. No vehicle older than 1996 is required to be tested, so OBD I and older are not tested.
There is no roadside pollution testing in Illinois.
I am sure the Federal anti-tampering laws are still applicable, but as far as I know there is no verification system and no one is looking under hoods or up tailpipes.

[Joe L.]

Re: 75 roadster exhaust judging

Joe,
State laws are widely different on testing requirements.
In Illinois only vehicles registered in certain counties (read the large metropolitan areas) are required to be tested. No vehicle with antique tags (25 or more years old) is required to have a pollution test. No vehicle older than 1996 is required to be tested, so OBD I and older are not tested.
There is no roadside pollution testing in Illinois.
I am sure the Federal anti-tampering laws are still applicable, but as far as I know there is no verification system and no one is looking under hoods or up tailpipes.

Terry------


Emissions testing requirements vary in California by county, too. Some rural counties have minimal or no testing requirements. All largely populated counties do require testing. However, ALL vehicles are still bound by emissions system tampering and functionality requirement. Of course, it's a lot harder to DETECT non-compliant vehicles without the requirement for bi-annual testing. As I mentioned, though, if a vehicle is detected as being a "gross polluter" by roadside testing equipment, that vehicle will be directed to a "referee facility" for inspection and testing. Also, even in the areas of the state where bi-annual testing is not required, I believe there's a requirement for inspection and testing at change of ownership.