https://www.thirdgen.org/techbb2/sho...hreadid=288512


thanx

 

this is pretty much a text book example how not to get meaningful replys

 

how so?

 

Generally it's considered poor etiquette to ask specific individuals for replies. That's what private messages are for, and some people could take offense when you preemptively discount their opinions.

Cross-posting to multiple boards is generally frowned upon as well, since it tends to clutter things up.

 

Put the AIR system back on. Buy a universal cat online, and you're ready to roll.

It's a bit harder to "cheat" the emissions tests when you have visuals. And passing one w/o a cat is very hard, you'd need a veerrrrrry good tune, and a great aftermarket ignition system.

The easiest way is to put things back to the way that they were. This is why I put the SMOG and AIR system back on my car even after the 350 went in... a little headache now, much easier on everything (wallet, hands, head, etc) later.

Either that or register it as an off-road only vehicle. Only problem then is that you couldnt legally drive it on the roads.

 

i agree and am sorry for crost posting as i originally posted it in exhaust but then realized it may have been better posted in the tech forum. as for excluding anyones reply i didnt intend for it to come across that way, i just figured a tech or mod would have more expertise in the area i questioned..........ive gained quite a bit of knowledge from vader in the past, hence my wording

 

the air system is long gone, the headers were double the price with the air, why i got rid of it, and the cat was causing my headers to get cherry red..............to be blunt, the car is staying the way it is.....i was looking for opinions on beating the test not redoing my car.............

 

I'm sorry that you arent getting the responses that you want. If you want I can tell you sure, waste money by pouring rubbing alcohol in your gas tank and that'll get you by.

Except... it wont. There's no magic liquid that will make your car run cleaner, if there was, then it would already be added to gasoline I'm sure.

At LEAST get a cat w/o AIR for the test.

I'm not trying to tell you that you need to re-do your whole car. I'm just trying to tell you what you're wanting to know... I'm sorry you dont like the answer.

 

If you are using blended fuel, there is likely already about 10% ethanol in the fuel. That's about 1½ gallons in a full tank. Adding another couple of pints of isopropyl alcohol probably isn't going to lower HCs significantly.

The addition of alcohol is probably more effective if you can get the inspector/tester to consume some before you hit the treadmill. Beyond that, you might want to consider the addition of a 3-way high flow cat converter (at least for the test) and get the engine plenty warm before your turn in line. Hold the RPMs up to at least 2,000 for a 90-second period before testing to get the cat adequately hot. If the EGR is working and the cat is hot, you should be able to get past the test with no air injection.

Have you already tried the test, and if so, what levels did you produce?

 

no havent tried yet, i run 93 or 94 octane thats about it,i have a piece of pipe welded in where the cat used to be,i mean i know the guy at the garage,he let me go with no cat 2 years ago,and also 3 years ago..................but i havent had this car back since it became computerized tied in to dmv..............had my other car there a few weeks ago, he gave me a readout that he said id have to bring to dmv when i go to reregister it.................didnt have any numbers or anything on it , it just said passed..............thought id get a jump on this if i could before i bring this car to him........

 

Not many states are relaxing emissions limits. Most are going the other way. New York is among those that are getting tighter. Unless you know what your emissions levels currently are, it might be difficult to suggest steps to lower them. Without a cat, your HCs are likely to be higher than the limit. CO is a maybe, depending on limits and how well the fuel is trimmed.

In any case, making that "91 firebird,mint" truly "mint" would include attaching a converter like the factory did. That is going to give you a lot better chance of meeting limits.

 

i originally tried a high flow cat years ago before i decided to do away with it , i did try , however my headers got hot as hell..........i was told it was due to the cats backpressure........

 

I was told there are thousands of cars on the road w/ cats not getting overheated headers.

 

so which cat on the market would give me the best flow, least backpressure and get me past emissions? and do these cats rob you of any power?

 

Random and Magnaflow (OEM'd by CarSound) are two good ones. I was running a Random when I dyno'd 290hp/360tq.

 

i see, well i know my exhaust is 2 1/4", should i get a universal thats 2 1/2" inlet and outlet? also , would you happen to know who sells these online at a good price? thanx

 

bueller?

 

You have a 2-1/4" exhaust and you're worried about obstructing flow??

You might not be getting many responses because most people who upgrade exhausts toss their 2.x" pipes in the trash and go for 3".

Maybe try Thunder Racing?

 

 

mmmmm, i was told by a tech at hooker that the difference between 2.25 and 3 was about 5 hp, didnt seem worth the money and effort to trash the whole system.........

 

I'm near positive that the tech at Hooker was thinking that you meant 2.25 inch DUALS to 3" single pipe...

 

Ask the Hooker tech to show you his SAE or other published references for that statement. That's when the BS stops.

 

my mistake, it was 5% , remember this is a 305, i could see 3" on a 350 but a 305? with 1 5/8 primaries?