Question: Dual Exhaust Install Question

[golfradict]

My 81 is bone stock, I really want a little more sound, so I'm thinking about removing the catalytic converter and installing true dual exhaust (not headers), (No problems getting inspections here) I want to stay with the factory mufflers also. My question is, will the computer adjust for this change? Thanks for any advice.

 

[Peer81]

The computer will not know the difference. I'm running it the same way (about the same way) without any problems or computer codes.

Greetings Peter

 

[Wajulia]

I was always suspect of my original cat restricting the flow and hp of my 81. Wanted to put a dual exhaust but I was worried about spending the money for little increase in performance. To check to see if i would gain anything, I removed the cat and poked a huge hole in it. Instantly the car seemed to pull a lot harder in the higher rev ranges. I am lucky enough to live near a dragstrip so I brought it the next weekend. Car went from 16.1 to 15.3. Eight tenth increase from banging the cat with a BFH. Best afternoon I spent in a long time. I bet your car will wake up a lot. But,while the sound got a little throatier it did not change the sound much. If you are really looking for sound think about flowmaster 40 mufflers

The 81 computer regulates the A/F mixture by monitoring the o2 sensor and modifies the mixture in the primaries only (normal driving). It will have no problem keeping up with a better breathing engine. When the secondaries open (3/4 throttle, drop in vacuum ) the computer backs off letting the primaries go rich and the secondaries operates like any other Qjet. The computer can deal with a better breathing engine with no problem. Only a bigger cam seems to bother it because the reduction in vacuum fools it into thinking the secondaries are opening early allowing the carb to go rich to early

 

[golfradict]

I was always suspect of my original cat restricting the flow and hp of my 81. Wanted to put a dual exhaust but I was worried about spending the money for little increase in performance. To check to see if i would gain anything, I removed the cat and poked a huge hole in it. Instantly the car seemed to pull a lot harder in the higher rev ranges. I am lucky enough to live near a dragstrip so I brought it the next weekend. Car went from 16.1 to 15.3. Eight tenth increase from banging the cat with a BFH. Best afternoon I spent in a long time. I bet your car will wake up a lot. Good luck

The 81 computer regulates the A/F mixture by monitoring the o2 sensor and modifies the mixture in the primaries only (normal driving). It will have no problem keeping up with a better breathing engine. When the secondaries open (3/4 throttle, drop in vacuum ) the computer backs off letting the primaries go rich and the carb operates like any other Qjet. The computer can deal with a better breathing engine with no problem. Only a bigger cam bothers it because the reduction in vacuum fools it into thinking the secondaries are opening early allowing the carb to go rich to early

Great, sounds like a good-to-go deal to me, can't wait to hear the extra noise

 

[Wajulia]

Great, sounds like a good-to-go deal to me, can't wait to hear the extra noise

Read my update about the sound!

 

[golfradict]

Read my update about the sound!

Thanks for the valuable info Wajulia, if the sound isn't quite enough I will consider the flowmasters