slo

iTrader: (1)

There is an article in some online ricer honda magazine, where a car was tested with stock cat,

metalic performance cat and no cat. The no cat made a whole 1 WHP and 1 FT LBS difference.

This care was in the 150 HP range, so even if its say 5HP, big ******* deal. And as has allready been said with a properly tuned and running car all thats needed to pass is a good performance cat, and an airpump

3rd Gen Jeremy

That's interesting. I've removed all my emissions anyway but from what I've seen, all FDs run a little smokey. I know mine sputters some black crap all over the garage door at startup. When I did a pull on the dyno, it was like batman just dropped a smoke bomb. Could have something to do with my engine being previously flooded but still, every car that was on the dyno was puffing some serious exhaust out the back.

I've never actually run with a cat, that's usually the first thing I gut when I get a car. I don't like restrictions. Also, I have a way around emissions testing.


Useful information none the less.

rynberg

Um, FDs aren't Honda Civics. A midpipe will make at least 20 more rwhp than the stock cat at the same boost level.

3rd Gen Jeremy

Are you running stock secondary rail? I had to remove my ACV for my top feed secondary rail. Without the ACV, the air pump is useless..... right?

Without the ACV, I don't think you can pass emissions. If you don't upgrade your fuel system, you're gonna be running at damn close to 100% on your injectors. It's gonna be cutting it close was what I really meant to point out.

I guess you could have your primary rail milled for 850s and keep the stock secondarys. I didn't go that route becasue I plan on making big power later. That's the only way I can see to keep the ACV and still run enough fuel to hustle that car through the 1/4 mile at 12.0.

Jeremy

slo

iTrader: (1)

Even with a cat they can sometimes smoke on startup. Did ya bounce of an ign cut rev limiter on the dyno, that will fill the room with smoke every time.

NTIMD8

iTrader: (1)

Any car with a turbo will see more of a gain when removing the cat.

3rd Gen Jeremy

To be perfectly honest, it was only on the first pull that Steve did and after that it was fine but I still don't think it would have been anywhere close to emissions ready. Probably just spit up some fuel that was still sitting in the engine. I had previously flooded the engine when I installed my new injectors and rail.

You also can't say that my car is not properly running, it runs perfect and silky smooth. My Narrow band reads stoic all the way through the rev range until I hit full boost then it runs right between stoic and rich. Steve tuned the car perfectly in my opinion.

NTIMD8

iTrader: (1)

Theoretically if any part of the emissions systems are removed you fail. I say theoretically because around here no places really do much of a visual. So if the shop knew there was a pre-cat on the downpipe I would fail since it is no longer there. Again I am not worried since they do not do much of a visual around here.

Keep in mind that the actual emissions tests are done when the vehicle is warm (I.E the cat has reached operating temp) so the crap you see at start up when the car is cold doesn’t mean anything when it comes to the test.

Next the sniffer tests are done at idle so there is no strain on the injectors or fuel system and the second test is done while the vehicle is on the rollers. The car is slowly brought up to speed (40km/h around here) and then kept there. Then the readings are taken. Very few cars would pass if they tested at wide open throttle. Despite what people are saying I honestly have no worries about passing with the limited mods that I plan. As long as the car is running right, the tune is good and there should be no issues.

I had 8 60lb/hr injectors on my lighting, huge pump and aftermarket rails and lines with a 2.3L blowzilla supercharger and it passed like it was stock. Why? Because everything was working like it should and the tune was bang on. A good tuner will tune for more than just wide open throttle.

NTIMD8

iTrader: (1)

Yup, RX-7's run very rich on start up. That's why we have the accelerated warm up on our cars to get the cats to running temperature faster.

3rd Gen Jeremy

You missed my point. Not that they're going to look at the ACV and know whether or not it's there or that you have a secondary rail. It's that the ACV controls the output from the airpump and without it, the airpump is useless. Also, if you have a top-feed secondary rail, you can't install it without removing the ACV. Has nothing to do with your lightning or any injectors. If you want to compare a piston powered truck( which has to meet a different set of standards since it is a truck) to a rotary, I don't think you're going to find many parallels. You can keep talking about your truck but you're comparing apples to watermelons.


I think that if what you're saying is true, the only thing that will make a difference on the rollers is the cat. The air pump only runs while the car is at idle anyway ( i think ) and is disengaged under load. I'm not criticizing you, I'm just saying there are a lot of factors to think about to meet your goals. From what people are saying it's doable but I still don't think it's very likely, it's setting the bar really high in my opinion.

NTIMD8

iTrader: (1)

My point is all this is moot because I am not removing anything that has to do with emissions on my car other than the pre cat which as mentioned only plays a role on cold starts. Everything I wrote had to do with "me" passing as people were saying I would not be able to pass with my planned mods...

You were wishing "me" good luck in passing and my whole poingt is "I" will not have problems passing with the mods I will be doing (which will land me in the 12's).

Now if you are talking in general terms when it comes to the RX-7 and mods that "others" do. I agree with you 100%.

PS, LOL at "apples to watermelons" Thats a bigger difference than Apples to Oranges.

slo

iTrader: (1)

You can actually pass without an ACV. You replace the ACV with a piece of pipe, its hard to impossible to actually see the acv without pulling the UIM. Then the air pump is perma connected to the air tube in the cat, and swiched on and off from a swich in the dash. The port air injection, which injects air right at the exhaust port to light the pre cat is then disabled, but the car will still pass just fine. Looking at the engine bay even with a flash light its really hard to actuall see that the ACV is missing.

NTIMD8

iTrader: (1)

Good info.

rynberg

Yes, I'm running 1300cc in stock secondary rail, plenty of fuel for up to 400 rwhp. If I need more, I can run 850cc in the primaries and still be smog legal.

As others have said you can bypass the ACV, but I don't have to.

3rd Gen Jeremy

Yeah, what I was saying was that if you have an aftermarket top-feed, you'll have to remove the ACV. I guess you're the guy to talk to if you want to run emissions. I personally don't do it but then again, I don't have to.

Jeremy

rynberg

Well, yeah, if I didn't have to I wouldn't worry about them either. But I do and I'm not willing to try to find a shady tech inspector to bribe.