Dual Exhaust

[LannyL81]

Any '81 owners that have replaced the stock exhaust 2-1-2 system to a true dual system using headers (not sidepipes)? Looking for brand of headers used and pictures of the exhaust piping routing.

Might be time to remove the sidepipes....may be.

Thanks in advance.

 

[jotto]

Hey Lanny,
Ive just purchased a set of stainless OBX headers and am waiting on them to be delivered from the US. Will then go to true duals. Do you have sidepipes? I would have bought some if it wasnt for the shipping charges....also couldnt fit them in my suitcase recently!!!!

As for pipe routing, I asked the very same question on another forum. Got a few replies with promise of pics but none appeared. People said they either changed the crossmember to one with the dual cut outs or others followed stock route but routed both tubes down the passenger side.

I did toy with the idea of running headers to 2.5 duals that exit just in front of the rear tyres.....poor mans sidepipes. With no mufflers might be a bit too loud. Only one way to find out!

At the Goodguys car show in Puyallup, I did meet up with Stan from Stans headers. Seemd like a really nice guy and his Tri Y Headers are very nice. Because of the design, it looks like they have extra ground clearance and they also offer ceramic coating. Price was a little high though. Think I paid $225 for the stainless headers and $112 shipping. Will probably get clobbered this end for import duty and tax!!!!!

 

[6880 Mike]

FWIW: the stock 81-82 exhaust manifolds are about the best GM ever made available; they amount to short tube headers. You could convert to dual exhust using the stock manifolds.

 

[jotto]

Mike Id heard also that the stock headers were good items. The only down side is all the extra pipework that goes with them! Only reason Im moving to stainless headers is my smog equpment is dead and for now, Id rather clean up the engine bay a little and drive her!
As time goes on, I will slowly try and find the missing/damaged components and put her back to stock.

Lanny, what sidepipes are you running?

 

[Peer81]

I do have true dual's with an x-pipe and ultraflows from dynomax. As for now with the stock manifolds. As I already had a 82 crossmember for my 700R4 I cut that up so it now accepts one pipe on each side. If you want pictures just say so

Greetings Peter

 

[Tom Bryant]

I used a pair of '81 manifolds on my truck. I. Removed the smog tubes, welded up the cracks where the 4 tubes joined and ground out the excess weld in the flange. Each port was reduced by maybe 10 percent with too much weld. Then I costed them. They look pretty nice.

Tom

 

[LannyL81]

Lanny, what sidepipes are you running?

Paul,
I currently have Hooker sidepipes...not actually on the car now as I removed them in order to paint the car. I just got the black ones as the body color was white. Not sure how these black sidepipes will look on a black car.....may be too much.....may be very nice......????


6880 Mike: I agree the stock exhaust manifolds are close to a shorty header and I could get the Corvette Central dual exhaust setup...which bolts right-up. But a true header is going to flow better and match-up to the Edlebrock Performer RPM aluminum heads on the engine. I just need to find-out what restrictions my local exhaust shop has with installing a non-stock system in an emissions controlled county even though the car is exempt from emissions.

 

[Nut]

I had Blackjack Alumicoat long tube headers put on MANY years ago. I did have to have them drilled and tapped for the O2 sensor. When I finally got to the "Historic" registration year level I was able to "remove" the CAT and had a local custom exhaust fabricator fab up a true dual set up with X pipe to a pair of Flowmaster Delta 50 mufflers that tucked up so sweet you had to look very close to see they were not stock muffs. The performance was noticeable and the sound was awesome!!

........... nut

 

[Tom Bryant]

They let you do that in MD?

Tom

 

[Nut]

They let you do that in MD?

Tom

No habla Tomas. :L Once you can get "Historic" plate(s) you never have to go though another emission inspection or even if the car is sold and re-registered Historic you don't even need a vehicle inspection. Now.....to get the true dual set up w/o cat(s), NO exhaust shop (could) by MD law remove the catalytic converter. That being said, my cat magically just "fell off" one day strangely enough right after I was testing out a new Sawz-All I had in the garage. I popped on a short flexible length of exhaust pipe to manage the sound and drove her over to my custom shop where the guy was more than happy to make me a true dual set up. I also removed all the other emission equipment except the o2 sensor and popped out the "check engine" bulb so it would stop annoying me coming on every 5 minutes while it was looking for all the emissions stuff that was missing. Car ran better than ever with noticeably more torque. Where there's a will..... there's a Sawz-All. :L

nut

 

[22229stingray81]

That brings up a good question. Does removal of the Cat cause the Check Engine light to come on? What component removal would set it off? I'm thinking about a true-duel exhaust myself... keeping the O2 sensors and all other smog equipment, but probably getting one of the Mid America "off road" exhausts. Will that cause the light to annoy me? :L


-Tatortot

 

[Peer81]

No check light when you remove the cat. It only gets air from the airpomp so the ECM doesn't know if the cat is there or not

Greetings Peter

 

[Nut]

That brings up a good question. Does removal of the Cat cause the Check Engine light to come on? What component removal would set it off? I'm thinking about a true-duel exhaust myself... keeping the O2 sensors and all other smog equipment, but probably getting one of the Mid America "off road" exhausts. Will that cause the light to annoy me? :L


-Tatortot

Hey Tot..... if you pull off the rest of the emissions stuff be sure to plug the lines. And yeah.... the light will drive you nuts (excuse the expression), so I just removed the bulb and changed the O2 sensors every 2-3 yrs as a rule. Like Peers said the cat doesn't effect the dash light. Good luck.

nut