Removing emmision systems to improve performance?
 

Hi all,
Before I do a tune-up, my next project is to remove any unecessary emmision systems out of my '78. I'm in New Orleans, and I bought the car from CA. We don't get any kind of emmision tests down here, so I'm trying to find out which systems I can/cannot pull out/plug, and what the benefits/drawbacks will be (gas mileage, HP, etc...)
Thanks.

Re: Removing emmision systems to improve performance? (marcfouchi)
 

Just a suggestion... Keep the catalytic converter or better yet, replace it with a couple of high-flow units. A car without a cat, well, just plain STINKS. I ran mine for a while without 'em, then put a pair back in (I now have dual exhaust).

Back in the '60s no one noticed, 'cause all cars stank. Nowadays, your car will stick out like a sore thumb if you pull the cats off. Trust me on this. :blueangel:

-Noel

Re: Removing emmision systems to improve performance? (marcfouchi)
 

I'd like to help, but I can't, my car didn't come with any of that in 68 :D

Seriously tho, most emission control parts are power robbers. Without fuel injection or electronic ignition, pretty much you should be able to yank all that crap off (catalytic converter too) and be safe until lousiana starts emission testing (and thats not too likely to happen). Probably gain 20hp or so from tearing it all of, maybe a bit more (depending on what is on the car). Someone who knows more of what is on your car might be more help... And the only drawbacks are when restoring it back to original for NCRS or a Bloomington Gold competition, or if the emissions tests do start...

Re: Removing emmision systems to improve performance? (marcfouchi)
 

I want to do this to my car too!!

Hopefully someone with info will help us out.

:cheers:

Re: Removing emmision systems to improve performance? (Metal_Wulf)
 

If you are serious about removing this equipment the biggest benefits will come from a dual exhaust as opposed to the 2-1-2 system you have now. Contrary to popular opinion the rest of that emissions gear isnt as big a drain.

the real problem with the car is the lower CR - and the restrictive exhaust.

Go to duals
remove the CAT (huge restriction)
remove the AIR pump (work always but not as big a drain as your water pump or alternator)
remove the EFE (when working properly only works during warm up)


EGR costs a little but there are other benefits which include added resistance to detonation. Dont remove the PCV - dont worry about the evap cannister.

All of this is of course - technically illegal, regardless of whether or not your locality tests as it is a Federal law you would be circumventing. But to the best of my knowledge there arent any federal smog police.

If all you did was eliminate the smog equipment - but kept your restrictive exhaust you MIGHT gain between 7-10 hp which frankly I doubt anyone would ever notice


[Modified by fauxrs, 2:20 PM 3/28/2002]

Re: Removing emmision systems to improve performance? (fauxrs)
 

My EGR valve or whatever that thing is, is seized up... Will that hurt performance any more?

Re: Removing emmision systems to improve performance? (Metal_Wulf)
 

Hey,

I think mine was too. I removed the original intake and replaced it with a pre-smog style edelbrock performer intake. This new intake did not have an EGR port in it - so no worries about plugging a whole. I ran the car for a year or two with the EGR stuck though. I didn't notice any difference. I wouldn't worry about it. Either plug the vacuum line going to it or replace the intake. You wouldn't believe the weight difference alone!

Rod Louisville, KY
:flag

Re: Removing emmision systems to improve performance? (rod73vette)
 

cool, ty.

Re: Removing emmision systems to improve performance? (Metal_Wulf)
 

Only if it is siezed in a partially open position - if fully closed - there is no negative effect

Re: Removing emmision systems to improve performance? (fauxrs)
 

The biggest problems I've seen with this is that people get half way and stop. A car with partiall emmision on it is bound to run like crap. Make every effort to disable all the emmisions except the egr and the cat. Follw the others advice and put a really high quality exhaust system on. A good tune-up is a must because a rich condition is a cat killer. Oh yea, for gods sake save all the parts removed for the future emmission patrol come to a town near you.

Re: Removing emmision systems to improve performance? (aqua80)
 

No emissions here. All the A.I.R. equipment was gone, and the EGR was plugged so I replaced it with a new one, then just pulled it and put a plate over the hole. Didn't notice a difference either way, but I only run 92 gas and a 73 L48 isn't a high comp. engine anyway.

Good advice above to think about re-jetting the carb and doing a tuneup (timing, choke, fuel mixture, idle speed, etc.) Taking all that stuff off is going to affect the way the car runs so you'll have to re-adjust all that stuff.

Definitely go true duals as well. Get rid of the 2-1-2. Dual cats or no cats is up to you. (I run no cats - love the smell of gas) :cool:

Re: Removing emmision systems to improve performance? (Corellian Corvette)
 

My '81 has had the EGR, EFE, AIR & Cat removed. I've also just removed the aircon to gain another couple of horses (only joking - it didn't work & was a lot easier to pull off than to fix). The only thing left is the charcoal canister, which I'm keeping. The car runs fine, no check engine light flashing at me, no hesitation, missing, etc, etc. As said above, don't do it half-heartedly, follow all the wires/vac lines through, work out what they are doing....... & then rip them out! I had problems with mine when I 1st got it as the EGR system hadn't been removed properly. Not worried about detonation without the EGR system as the CR is so low.
I run dual pipes (2 1/2") without cats (with what we have to pay for fuel I wanna hear & smell my money being burnt ;) ). I doubt if removing any of the emission systems had much of an effect on HP, apart from the dual pipes. That was really noticeable :)
The way I look at it is that the emission stuff is just clogging up the engine bay & is just a load of stuff waiting to go wrong & cause you a real PITA.
:cheers:

Re: Removing emmision systems to improve performance? (UKPaul)
 

Yea, duals and high flow mufflers makes more difference than anything else I've done as well. :cheers:

Re: Removing emmision systems to improve performance? (KENTUCKY81)
 

Hmm, well, I guess I won't bother taking off anything until someday down the line when I get duals. Doesn't sound like its worth the trouble for what you gain without changing the exhaust out.
However, if I ever need to do major engine work and find that I have to take any of those things off, I'll probably just leave it off, plug up the hole, and re-tune. Just one less thing to take off again later! :smash: