Dual Exhaust Conversion on an '81

[ducvw2004]

I'm planning on converting my '81 to a true dual exhaust.

The plan is to use long tube headers with a chambered exhaust.

I will be deleting the catalytic converter (no emissions required on a car this old in Georgia). The oxygen pump is already gone.

The car still has the original carb and computer controlled ignition. I plan on welding in a bung for the O2 sensor.

Has anybody else done a similar conversion?

Anything special problems I need to consider?

 

[damoroso]

I did true dual exhaust on my 81, though I went through mufflers rather than using a chambered system. I went with 2.5" aluminized steel pipes. I didn't elect to go with long tube headers though, without any other mods, I didn't see the benefit over the factory header type manifolds. The car does feel a bit better but let's face it, the 81 is pretty anemic in factory trim. You'll have to do quite a bit more than an exhaust system to get appreciable hp gains.

For me, I get the big block back from the machine shop next week, that's how I'm going to wake mine up.....

 

[teemar_99]

I just got my 81 back on the road with dual system and shorty headers from Corvette Central. I have to say I love it! Last fall I added an new cam and 64cc Edelbrock heads. The factory set up was choking the engine. Now it is alive and sounds great. Best of all it was a simple install.

 

[spikebot 81]

I think long tube headers and duals made a big diference. The car can even squeel the tires from a dead stop. Plus with 2 1/2" pipe and magna flows is scares the ricers away.

 

[ducvw2004]

I did true dual exhaust on my 81, though I went through mufflers rather than using a chambered system. I went with 2.5" aluminized steel pipes. I didn't elect to go with long tube headers though, without any other mods, I didn't see the benefit over the factory header type manifolds. The car does feel a bit better but let's face it, the 81 is pretty anemic in factory trim. You'll have to do quite a bit more than an exhaust system to get appreciable hp gains.

For me, I get the big block back from the machine shop next week, that's how I'm going to wake mine up.....

One issue I have now is that the previous owner put shorty headers on the car and retained the stock 2-1 exhaust. The collectors have a pretty sharp 90 degree bend in them and reduce to a 2" pipe. If anything, its probably choking the exhaust flow, so the move to long tubes and dual exhaust should yield some hp increase.

My short term goal is not to build a fire breathing monster...just get better performance out of what I have.

Besides, the chambered exhaust sounds great!

 

[damoroso]

Changing to a true dual system will certainly allow the engine to breath better, no doubt. I'm not sure how much going from the shorty headers to long tubes will help on a stock engine, especially for the cost. It'll be interesting to hear your opinion on the increase from what you have now. I think the biggest benefit to putting on long tube headers at this point would be that any other modification you might do to the engine will work better with the exhaust system you end up with. At the end of the day it's what works for you. After all, that's what really matters, your opinion for your car!

Good luck, let us know how it turns out!