Be careful about no-cat comments!

Interesting...but I wonder...does anyone have first hand experience with having been cited for missing emission controls...let alone being arrested, prosecuted, fined or jailed?

This is a hot topic on may car forums...but I have never heard of anyone ever being chased down....not that it couldn't happen.

Dave

 

I've got a coworker with a Mitsubishi Evolution, and apparently, Mitsubishi is scanning the various web sites to find evidence of people using their cars on the track, and therefore deny warranty work.

It would be smart for govt employees to do the same (generate tax revenue), but then again, smart and gov't employees are 2 things that do not go together

Dom

 

Hey ... I was a Federal Government employee at one time: oh, yeah guess you are correct!

The problem with this type of penalty is one never knows when the government may have time on its hands and starts looking for some poor car owner to make an example of so as to scare the rest of us ... with an email trail and a car that is modified it wouldn't even take them long to make a case.

Best wishes

 

Or when they might initiate a reward program for those who report people known to be in violation. Saves the Gov't the time needed to do the searching, & provides a HUGE incentive for informants. You wanna bet someone wouldn't rat you out for $50 if given the opportunity??

 

Test pipes are for track use only.

Water pipes however, can be used all the time.






-Daniel

 

i have no cats
no O2 sensors
and
run high octane fuel

 

Dear Ferraristi,

Ahhhh America,


I remember when it used to be a free country.

 

Same for me. But my two cars that I do that with are a '69 and a '70. Both Jaguar XKE's. Pre-CATS. Exempt from inspection.

I think the point of this thread is correct -- removing cats and running the car on the street is risking potential fines and forfeiture. In this area of the Northeast, the cops will sometimes set up inspection checkpoints and randomly check cars for registration, inspection stickers, and check basics like light, emissions, etc.

Chances are, most won't get caught. But if you do..... Guess some people are more willing to take risks or simply ignore them. Best of luck.

 

It's a free country until you start compromising the LAW!

 

I thought FL didn't have emissions checks anyway?

 

Any mention to no cats on this board only refers to track use and we always but them on after the track

DISCLAIMER - I have no pecuniary gain from any potential transactions, do not remove tag under penalty of law, return your trays and seats to the full upright position, product may settle during shipping, closed roads with professional drivers, never try this at home, etc.

 

I have Hyperflow cats - sure they cost more than test pipes, but for a demographic who buys $400 floor mats it shouldn't be a big deal. They were less than OEM replacements, look better, sound great, flow nearly as well as test pipes according to their manufacturer. And my exhaust doesn't stink.

Not affiliated in the least, just happy with the product, the sound of my exhaust, and with being smog-legal 24-7.

Cheers
Kevin

 

If removing the factory cats. only results in approx. 5HP gain what is the point of spending any $$ on less restrictive cats.

 

He states they are less than the OEM cats, so if you need to replace them maybe?

 

You have to decide how much credibility you assign to the 5 HP claim.
The engines I develop lose more than 5 HP due to cats.

 

Only an assumption here but I believe were discussing factory spec motors with either no cats, secondary cats removed or aftermarket cats installed. I would also assume that depending on the model/yr. the cats would have more or less effect on the overall performance of the motor.

 

Hey guys, as an automotive engineer I have to mention a couple of facts.

1) Catalysts only work near 90% efficiency when the air-fuel mix is near stoichiometric (14.5:1) and even then, only in a relatively narrow temperature band.

2) High performance cars are seldom operating with stoichiometric fuelling, actually whenever they are driven hard with lots of transients (i.e. accelerations) the fuel-air ratio is extremely rich. Also, driving EXTREMELY hard (i.e. on the track) will send your cat temperatures skyrocketing.

Therefore I can say that when driving a Ferrari for fun on a twisty mountain road or on the racetrack the cats are operating nowhere near their optimum - if you are lucky they'll give you 30% pollutants reduction.

On the other hand, whenever you are driving your Ferrari at stabilised speeds on the highway or in town the cats give beyond 90% efficiency, which for me makes it all worthwhile - clean air is worth a paltry 5 HP loss...

Besides, your engine performance will not increase simply by removing the cats - you'll have to re-program the ECU as well. All you are doing otherwise is to foul up the environment unnecessarily (and there are enough disgusting SUVs doing that already, we shouldn't help those who want add Ferraris and sportscars in general to the black list...)

 

We have to keep HP gain/loss in prespective. Early cats, for example '78 -'79 carb 308, were in their design infancy. Very restrictive flow properties robbed HP which was already low due to other steps to reduce emissions such as mild cam timing, air pumps and lean jetting. With those cats removed Hp gains could be a significant percentage improvement.

Today's cats, combined with digital engine management, are very effective at emissions reduction without draining performance. Car manufacturers do have to lean toward the worst case possibilities as far as maintaining long term emissions standards and equipment durability so they won't be quite as HP friendly as a high performance after-market cat.

IMHO, performance gained by just removing a late model cat is probably more from weight reduction (physical and financial) then anything else.

Although it pains me to admit it, Frank is correct. Environmental "authorities" are not car lovers and would not hesitate to use their powers to advance their agenda, personal and professional. How many car enthusiasts sit on the BAR commission?

On a side note, when I was in high school during the muscle car era, a friends father was a zone manager for Chrysler. He would occasionally take us to the drag strip, we watched the race while he took down the license plate numbers of the Mopars (no warranty work after that).

just my $0.02 worth

 

I tend to agree with an earlier post which suggested there will be no hp gain by just removing the cats (there will be weight loss). The ECU will have to be reprogrammed to take advantage of the new set up (verified through some of the aftermarket guys with headers/pipes,intake/exhaust with ecu mods). There is absolutely no reason why some go with test pipes other than sound enhancement, I doubt if they do it for the 5 or 10 hp gain. Afterall, the gain is so minute it is hardly noticeable in a 400 hp car.

 

Everybody loves to talk about "modern cats" and how much better designed they are. As emissions standards continue to tighten, you're right, they're better designed. To improve emissions reduction.
While they don't use the perforated flow cones my 308 cats have anymore, they're using higher and higher cell densities to get more catalyst surface area. That means putting MORE substrate in the exhaust flow. Granted this comes along with thinner wall sections, but let me tell you, the bricks in old cats aren't all that much different from those in tomorrow's cats in terms of flow restriction.
I'm only speculating about all these "high performance" cat replacements, but I'd assume they don't provide the same level of light-off performance, nor likely the high mileage robustness that OEMs are required to demonstrate for a production application, so they can use less substrate and reduce backpressure.
To give you an idea of the relative importance of a "modern" catalyst in exhaust flow, a certain domestic manufacturer recently updated the cats in a particular application and, in addition to paying more for newer technology in the substrate, also spent more to use two different bricks in the two halves of the catalyst so the 2nd one could be shorter. Why? Backpressure. The newer bricks were more restrictive, so to get to the same backpressure level the old system had, the new brick had to be made shorter, lest the ECM need to be recalibrated.

I don't suppose this will put any end to the claims that removing a modern cat doesn't have much impact on backpressure, will it?

 

I had to replace the factory cats as I am in California and the car's original cats had either disintegrated or were punched, so didn't really have a choice since the car failed the smog check in spectacular fashion.

Since I had to buy new cats anyway I went with Hyperflows. The point I am making is not so much with regard to the horsepower gain - I think most people add test pipes for the sound and perhaps some "seat of the pants" horsepower. Just suggesting that for a few dollars more you can get both the aural delights and what seems to be a bit of throttle response (might be the Tubi) and still run legally.

My $0.02.

Cheers
Kevin

 

Kevin,

Wasn't there a big price difference? I have noticed the aftermarket cats are almost 1/3 the price of the OEMs.

 

To tell you the truth I didn't really price the OEM's - as soon as I failed smog and was certain that it was my old cats I immediately went for the Hyperflows for, well, the flow. According to Hyperflow's website an OEM converter is c. $1400 compared to c. $800 for one of theirs. I paid less than 50% of the stated OEM price here and with the Tubi the whole exhaust sounds great.

Cheers
Kevin