What years will fit?

[Blackdog2]

Just purchased an 89 coupe and it has a full 2 3/4" straight pipe exhaust. No mufflers. What other year C4 exhausts will bolt up?

Thanks

 

[boomdriver]

Just purchased an 89 coupe and it has a full 2 3/4" straight pipe exhaust. No mufflers. What other year C4 exhausts will bolt up?

Thanks

There will be slight difference between converts, coupes, L98, LT and OBDI, OBDII cars (Y-pipe and o2 sensors) Cat size and mounting. Pre-Cats on the first 3yr L98s.

Short answer....they're all gonna be slightly different. Nothing that a torch can't fix. The most common piece would be the mufflers and rear Y pipe. Tips changed annually. NBD there.

 

[Blackdog2]

Cool thanks, so if I bought a used exhaust from an 84 it should be a fairly straight forward install?

 

[Jeb]

Cool thanks, so if I bought a used exhaust from an 84 it should be a fairly straight forward install?

If that used exhaust is in stock configuration, that would be correct. Before you purchase it, you may wish to check.

You could also mix-match some new parts from Ecklers or Mid_America and save some problems down the road. For example, you might be better served with a new front Y-pipe with or without pre-cats if you don't know the condition of the pre-cats on the used system. Same for the cat convertor. These are things that can come back and bite your wallet down the road if they go sour.

 

[boomdriver]

If that used exhaust is in stock configuration, that would be correct. Before you purchase it, you may wish to check.

You could also mix-match some new parts from Ecklers or Mid_America and save some problems down the road. For example, you might be better served with a new front Y-pipe with or without pre-cats if you don't know the condition of the pre-cats on the used system. Same for the cat convertor. These are things that can come back and bite your wallet down the road if they go sour.

Thats what I'd do....get a new front Y pipe without the pre-cats...and once that section is fitted to the midstream section, it should all fit like factory.
Do not bet your life on it though...
Have a torch handy to make some mild bends and to adjust brackets. Exhaust work in the driveway is challenging at best. Rusted nutz, broken bolts that came off rusted nutz....hangers that don;t quite fit. It can be done if you have the resources to see it through to completion.

For a long time I ran mine with a big front Y (no pre-cats) then a large diameter center section and main Cat, then a larger rear Y and Borla muffler eliminators....it sounded great when you were outside or when stepping into it but the roaring drone of hiway cruising nearly drove me insane....a constant roar like sitting next to a train track. It got real old real fast...... :ugh

Kept everything except the rear...added some brand name mufflers so I could hear the stereo again.

 

[Blackdog2]

It's not my intent to keep the car long term... I'd like to get things in order on the car and sell it to upgrade to a newer C4 or possibly a C5. I actually have it in my basement so I can work on it through the winter months here in Maine... The exhaust thats currently on the car won't pass a Maine inspection so it's sorta toward the top of the list...it's a 2 3/4" mandrel bent system bent by Hennesy performance. whoever that is. was told that by the previous owner.... No cats, no Mufflers... it's very loud but looks almost new..also hangs a bit low..I'm not opposed to doing all new as long as I can get it back to inspectable at a reasonable price... going to do a little googleing and see what I can find...

Thanks for the info!

 

[boomdriver]

It's not my intent to keep the car long term... I'd like to get things in order on the car and sell it to upgrade to a newer C4 or possibly a C5. I actually have it in my basement so I can work on it through the winter months here in Maine... The exhaust thats currently on the car won't pass a Maine inspection so it's sorta toward the top of the list...it's a 2 3/4" mandrel bent system bent by Hennesy performance. whoever that is. was told that by the previous owner.... No cats, no Mufflers... it's very loud but looks almost new..also hangs a bit low..I'm not opposed to doing all new as long as I can get it back to inspectable at a reasonable price... going to do a little googleing and see what I can find...

Thanks for the info!

Its been my experience that most inspectors are NOT aware on which vettes from the 80's are supposed to have pre-cats...so as long as it passes the visual with the main Cat, and has the air-pump and tubing to the exhaust, and the smog test, its golden.

All you have to do is cut behind the front Y,.assuming that its not a true-dual now. Where the Y comes together is 3" or 3.5 stock at the main cat inlet and exit, then it reduces in the rear Y and splits to each side of the rear to mufflers & tips. If its been done true-dual....nothing can be saved.
Enjoy your winter project !