82 Headers and Exhaust
 

Hello All!

Recently purchased my first ever Corvette, (1982 Cross Fire Injection all stock with 61K original two owners), this is also my first post on this board (of many I am sure). I am pretty much a novice when it comes to working on cars except for tuneups, oil changes etc...however all my friends are now building cars and thought it was a good time to jump into the fray. The C3 Vette has always been a favorite of mine and i found a sweet deal so i went for it. I have been reading these forums along with any other information i can get my hands on about the C3s and the L83 engine.

So the first question I have concerns Headers and Dual Exhaust. I am looking for a horsepower increase of course and I want a nice deep rumble but not anything where I wake up the neighborhood unless i want too. Not looking to be cheap as far as cost but also not wanting the cost of the highest end racing setups neither. Something that just gets me some extra push with a nice sound.

Any recommendations are appreciated!

Thanks

Tim

1. Does the state it's registered in have yearly emissions tests?
2. Do you realize your ignition and carburetor are computer controlled and rely on feedback from oxygen sensors in the exhaust system?

Depending on your answers it will be easier to find headers.

No, i don;t have to worry about the emissions in my state, as far as the ignition and injection I can't seem to find any definitive answer on the problems the headers would cause, so i am open to suggestions and will research more. I am ok with adding headers that are set up for the emissions if i absolutely have to.. I have pretty much determined that the CAT can come off?

Thanks

Congrats on your CF purchase and hope you have a blast with it. You have several choices in headers, I have used Hedman ceramic coated for decades now which helps to keep the heat down and they are relatively painless and go in from the bottom except when it come to the header tube for the power steering cylinder. You will have to ding it in a little, but that ding will not affect the flow in any way. There are others that you can use as well like Doug Thorney Tri-Y's which are a good choice as well.

If you remove the CAT, go with a X-pipe which will work out well. I also went with the G-Force cross-member (note: the Gforce part will say its only good up to year 81 corvette, it will bolt directly in your 82 as long as you have true duel exhaust like mine with no issues) which makes going to true duels a lot easier to make the exhaust from header to mufflers. I also used Hooker Max Flows 2.5". They are fairly quiet at idle, but at WOT, they sound great.

Here are a couple pics of my exhaust on my 82. Good luck with your choices. :thumbs:

https://cimg2.ibsrv.net/gimg/www.cor...887a7efd01.png

https://cimg3.ibsrv.net/gimg/www.cor...6beae7a23f.png

Buccaneer

Thanks for the suggestions,your setup looks awesome! Since you did exactly what i want to do with the same year did you have any issues with the ECU? Did you remove the smog pump or were the headers set up to accept the emission fittings etc...?

Thank you. If you want to run the smog pump, those Hedman headers have the fittings for the one-way valves ang A.I.R. tubes. Mine does not have those anymore and my pump is now removed. I run a 383 vs. the stock 350 and have a lot of changes, but the exhaust between our cars could be the same if you want it that way. The ECM should be OK with the change, make sure you use the O2 bung for your narrow band O2. You relly need to know what your fuel pressure is on a CF motor. Once you put headers on it, ensure you run 13PSI measured in-between the TBs and the motor will run just fine. BTW, enjoy the increase in power. :thumbs:

If you don't use the cross-member that I used, it will make it more difficult to install the pipes. Since the new cross-member is a pass through bottom setup, it is really easy.

Here are two recent pics of my motor. Getting the car ready to go back on the dyno next week to tweak in the new mods I just added. :D


https://cimg3.ibsrv.net/gimg/www.cor...eab7fc75fa.jpg


https://cimg3.ibsrv.net/gimg/www.cor...acd4211351.jpg

The ECU doesn't know/care if you unplug all the air control solenoids. I removed all that when I bought mine, and have never had a check engine light. This photo is a bit old, I have since removed the EGR valve and installed a block-off plate.

until you decide what to do with the headers , I would open up the cat or replace with a new one .you will be surprised how bad the old cats were.

Buccaneer

A few more questions if you don't mind. :)

1) Since i will be having a custom shop build this up for me do you think I still need the different cross member? If i can avoid the extra cost of approx $250 that will be more dollars i can put into another part of the car.
2) What are your thoughts on mid length headers in this situation? The reason I ask is that they would help with ground clearance and i have read that full length is better at higher rpms but at the cost of low end power. (I could be way off on this, but there is so much conflicting info out there).
3) Concerning the X-Pipe. I see there are many different types. Which manufacture/model did you use?
4) Which Hedman Header did you go with? I notice they have an Elite series with thicker steel and a thicker flange? Ceramic coating is "unpolished" though, not sure how these would look. But the thicker flange will probably help avoid any warping and leaks.

Thanks

Thanks! BTW my 1982 is also Silver Blue/Dark Blue. Do you have the blue interior? One of my future projects is new seat covers and carpeting, wondering if you have been down that road yet?

Yes, dark blue interior. If I recall, that is the only interior color offered with the two tone SB/DB exterior. My seats are original and in excellent condition, but the carpet is pretty faded. Here is a photo from when I replaced the backing on one of the side panels. One of these days I'll spend the big bucks to replace all the carpet, but for now, I am just rolling with what I have.

Post some pictures of your car if you have them!

https://cimg4.ibsrv.net/gimg/www.cor...e254398c10.jpg

1) The reason for the different CM is it makes it much easier to install a true duel system straight back. With the stock CM it is meant to go from two, into one and back into two pipes. If you look at the stock CM, you will see that it is odd shaped to accommodate the CAT on the right side. You can go stock, but it may not look right when done. Your call on that one. I wanted easy, but I understand cost as well.

2) Don't get hung up on header length since you are running the stock motor, it won't matter and you won't feel any difference between them if you did a comparison. Headers are really designed to be un-capped and run that way to give to max HP. To get max HP from a set of headers, you would have to add approximately 17-22" of 3" collector to your headers and run them open. When I go to the track, my headers are open and because I made the system one piece, it makes it easy to drop. The Hedman I run don't hang any lower than any other headers and don't go lower than the oil pan bottom anyway. My car sits a little lower in the front and rear than stock, but that's what I wanted it to ride at, even and lower.

3) My X-pipe I made myself as I was fabbing up the tubes, easy to do if you have the tools and a TIG. Any X-pipe will do really as long as the angles are correct for your application. Maybe the shop that is doing yours can fab you up one as well. Just cut out the center of the bends where they meet.

4) Go with the Elite, they do have the thicker flange, much more stronger. I would also go Ceramic coated for heat reduction and long term looks. Again, the choice is yours.

Here is where I bought my CM, but I see they have increased their prices, too bad they did that. Maybe you can find it cheaper if you go that route. https://transmissioncenter.net/shop/...transmissions/

Here is a good article to read on exhaust systems: http://www.superchevy.com/how-to/exhaust/0505phr-exh/

Here is some info on mufflers as well:

https://cimg0.ibsrv.net/gimg/www.cor...0683d667b6.png


https://cimg8.ibsrv.net/gimg/www.cor...3b8c7324a1.png


https://cimg9.ibsrv.net/gimg/www.cor...35a33a499d.png


As a side note...The 82 vette two tone Silver Blue/Dark Blue like yours and garrettb has came in two interior colors only. DB=Dark Blue and SGY= Silver Gray

Hope this helps. :thumbs:

Glad I could help you out and hope your project works out well for you. You can hit me up anytime if you like. I will always answer and give you my input and my experience on CFI.

When I added headers I went with Mid size stainless headers, No air pump, cat delete pipe and Magnaflow mufflers. I retained the factory Y pipe and O2. Added a Chip for the computer. Ran and sounded very good.

Look familiar?
Exhaust shop just sent me this pic. All your recommendations worked out nicely. Can't wait to hear it 😁
https://cimg5.ibsrv.net/gimg/www.cor...717ed3d768.jpg

Ooooooo looks nice !!

That looks really nice, well done. I bet it will sound good as well. :thumbs:

So how does it sound? :steering: