1Bad85Rex

OK, I've decided to try my hand at fabbing up a custom exhaust to put on the rebuilt, st. ported engine, but I have a problem: EMISSIONS TESTING. I've been racking my brain trying to think of ways to pass emissions w/o having to switch the exhausts. BTW it will be 2" headers leading to two separate sets of cats and presilencers and two 2 1/2" pipes leading back to (as I plan it) two Powerpulse mufflers. Here's what I've come up with so far: DLIDFIS, aftermarket cat, maybe set the idle a bit high. What else could I do?

RotoHead

Well, for starters, you could be lucky you aren't in CA. There isn't a whole lot you can do here. Passing visual can be a pain in the rear. It doesn't matter what numbers you put out if you don't have CARB (Pronouned: California Air *****)numbers on everything from the Cats forward. And from what I have gathered there is only 1 company that makes a catalytic converter that is CARB legal. That being Mazda at about 3 grand for all three. Ewww! Okay, I am done rambling.

Chris

1Bad85Rex

Well, as far as i know, around here the emphasis is put on what is coming out of the pipe, not the pipe itself, plus i've got a couple friends working in garages around town who say they would be willing to look the other way on the visual inspection, but they would appreciate it if I would make a great effort to actually pass the test. I'm currently in the process of finding an "emissions guy", if you know what I mean. *wink, wink*. but if that doesn't work, what can i do. another though came to mind. Would placing spark plugs somewhere post-header help burn up anything that may cause me problems? I'd be willing to live with some backfires on emissions day if I could turn them off the rest of the time. Of course, there is one county in my state that doesn't do emissions testing, maybe i should go there, buy a shanty, and re-register my car (just a thought)!

yayarx7

maybe a dual cat system with the airpump directed into them?

WackyRotary

Dude, you need to find someone with a non-altered RX-7 that someone will allow you to put your plates on and go to the test and pass. That would be easest. I think if my state ever starts testing again, I will nominate someone car in the club as "test Mule" for emissions tests for everyone with a 1st gen and maybe I'm just babbling. he he. But its a idea.

riffraff

wacky, biggest problem with that is the VIN's.... they will not match

nimrodTT

riffraff,
If it's an 83 or earlier (haven't looked real close on the later ones in a while) those vin plates on the dash can be swapped out with just a few screws. Or you could just bribe the guy - I have yet to meet one that's not crooked.

1Bad85Rex,
powerpulse is a air filter, I think you mean primaflow, and where is the second one gonna go? Gas tank is in the way on the left.

riffraff

problem with the switching the vin plates (trust me, i have thought about it) is that there is also a vin burn into the firewall right next to that plate.

also, 79 vin plate is different from that of an 80.. not sure how they compare to 81-83 but i would gess different again.

1Bad85Rex

that's a good point nimrod. I was actually going to just run them both out the rear passenger side, but now that I have put some more thought and research into it, i'm gonna go with 2" headers leading into a 2x2" in-1x2 1/2" out catalytic with a reversed header reducer opening the midpipe up to 3". This way I don't have to spend all that damn money on 2 cats, 2 presilencers and 2 mufflers. still get good airflow for much less money.

nimrodTT

I was talking about the one on top of the dash. And honestly, who has seen one of the technicians cross reference vin numbers on the car?

peejay

Wen you take your car to an E-check the first thing they do is take your registration and confirm the VIN and license plates. Then they check your mileage and enter it all into the computer.

Nice thing about the E-check is that it is free until you pass... so you can just keep diddling with the car until it passes. I did that once in the parking lot of the test center "Ok idle HC's are a little high, so is NOx, let's try leaning the idle mixture a bit, bumping up idle speed, and retarding ignition timing..." Car passed with 449.1ppm HC's with a 450ppm max. It don't get much closer than that