De-cat pipe? Usefull or not?

I took mine off of both my GT4 and Mondial t.....

Might make a difference in sound (a touch louder), slight benefit to free-er revving (if your cats were a bit clogged), but very often increases the odor (especially in your garage) after a drive.

The larger sound improvement is a free flow exhaust adder.

 

Years ago when I had a 308QV I dyno'd before and after replacing the CATS with a test pipe. It gave me a 1hp gain. It also gave me some resonance at lower RPM and when stopped at a light, my eyes would burn from the fumes coming back in when the top was off or the windows down.

 

A cat bypass pipe doesn't do a lot in terms of performance. It does add odor. You can't pass emission testing without it. The big advantage is that a catalytic converter can't catch on fire if it's not on your car.
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+1. The only benefit is a reduction in temperature and fire risk.

dave

 

There are even dyno tests showing a slight LOSS in HP when a cat is removed! So never remove one thinking you are going to increase any power unless, as noted, the old one is clogged or disintegrating internally. I wasted money putting on a hyperflow cat because I THOUGHT my oem cat was coming apart - heard rattling. Turned out it was a fitting that was rattling and the original cat looked virtually new inside. Should have pulled the cat FIRST instead of ordering a new one without checking thoroughly. Oh well new Cat is shiny!

 

No odor from my car and I've had a "test" pipe installed on occasion. Didn't dyno it but it does seem rev happier and be a bit "peppier". The piece of mind I have for getting that blistering hot cat out of there is worth it. I have the cheapo Stebro pipe.

 

Cats restrict airflow from the engine, trap engine heat, and if your ignition system goes flakey the cat will receive unburnt fuel from the engine where it will ignite and cause a fire inside your exhaust system.

 

replaced mine...slight odor when I first did it. But no smell anymore. She runs cooler...a good thing here in the hot summers of Charleston.

 

"Cats restrict airflow from the engine."

In 1978 that was probably true. Since at least the mid 80's it is not. Look at any DYNO test that was NOT published by someone trying to sell you something and you will find that Cats don't reduce power at all. Taking a cat off a car that came with them and substituting a "test" pipe will make no difference. As I stated before, there are dyno tests showing that removing a cat actually reduced power.

It's the same thing as thinking an aftermarket exhaust system produces more power when most commonly they just produce more noise.

 

I saw a small flame in that area of my car once. My car is old enough that it will never need to pass another emissions test here in Virginia. I don't care about horsepower but I do like the idea of getting that heat sink out of there. I also don't like the looks of the diaper that they covered the cats with. I'm not really looking to make it any louder either. How much louder is it without the cats? Are there down sides to removing the cats? My car is a QV. Will the fuel injection system system work correctly? I don't know how sophisticated the fuel injection is on a 1985 Ferrari 308 but the fuel injection system on my 1994 Geo Metro has a feedback loop that probably would not function correctly without the cat.

 

I have an 84. No problems and not any louder that I can tell. The test pipe has a bung for the O2 sensor built in.

 

It will be very slightly louder and a little smellier. The FI will work fine.

Dave

 

I stuck a Larini test pipe and exhaust on my 328 and, without question, the performance has improved. And it's not just my perspective but also that of others who have been in the car, as well as those who have driven it. And let's not even get into the sound difference... That being said, my old cat was in rather shabby shape so not sure how an "intact OEM cat" would compare. I have not had any problematic smell and, in fact, like the extra little "raw smell" added by the test pipe. I would suggest that you also add the aftermarket muffler if you're seriously considering the test pipe. I have been REALLY pleased with the Larini System and it's waaay less expensive than a Tubi.

Cordially,

Scott

 

In a word, F*ck No!

It is totally lame to eliminate your catalytic converters. For $100 each you can buy free flowing Magnaflow metal substrate cats at Performance Peddler.

You want the 2" model: http://www.performancepeddler.com/detail.asp?PRODUCT_ID=MAG59954

Have a competent shop weld them in place of your existing cat's elements. Your car will run great, and you will not be poisoning the atmosphere. No excuse for that sh*t!

So that there is no misunderstanding: I do NOT think that CO2 is a pollutant. On the other hand CO, NOX, ect. are poisons and need to be catalyzed. Drive your car till the wheels fall off! I am totally with it as long as you are not spewing poison.

 

BTW the new metal cats are smaller than the old ceramic ones so, although they get just as hot, the heat is further away from everything. On the other hand, if your cats are getting super hot, you have a problem with your A/F ratio. Removing the cats won't fix that - you need to repair your induction system. Once that's done your engine will run better, and your cats will operate as intended.

 

I just purchase and installed the same for my 328 (Larini test pipe and exhaust). Can't wait the the weather warms up to give it a try. Nice to hear you are happy with yours. I was very impressed with the finish/fit and welding.

 

Most every system failure occurs during engine operation, and the only warning the driver gets that his exhaust system is on fire is the illumination of the 'Slow Down' lamp (IF its working and the thermocouple isn't damaged or removed). Otherwise, the flames eat through the cat and spread to the trunk and engine compartment. Unless your exhaust is made of glass, or you have a closed-circuit TV camera stuffed in there, you won't be able to see what's going on until its almost too late. Its not worth the risk - ever. I think even the purple-haired tree-huggers can agree that a engine-fire burning Ferrari produces much more pollution and damages the environment more than a cat-less one that's typically driven less than 8,000 miles a year.....

 

DAC, will be interested to hear what you think I agree...the fit and finish are great. Also, there's no welding and, I'm sorry, but there aren't enough Ferraris, nor enough Ferraris driven often enough, nor enough Ferraris with test pipes driven often enough to cause one iota of difference to the environment.


Cheers!

 

You are in your garage running the car for whatever reason, and the garage fills with puke. Yuck, it's nasty and not necessary. That was the bad old days. Fix your induction system and quit friggin around. If you are really concerned about excess fuel leading to a fire, then install a wide band O2 sensor and stoichiometer. You will have plenty of warning about improper F/A.

I simply have a look after driving to monitor my cat temps. It's not rocket science.

 

I am curious: is there a danger that carbs in reasonably good condition will suddenly start puking fuel? I don't understand what the fear is about. Yes, if your carbs are wornout and leaky, I suppose they could be out of tune enough to raise cat temps to a dangerous level, but, barring that, how could the concern bruited ever become a reality?

Of course if your carbs are that bad, you really should get them fixed, for a lot of reasons, no?

I'm really curious...

 

There are no carbs on a 328.

There is, however, a dual independent spark system, which can drop one bank without notice. No matter how carefully tuned, half a motor dumping unburned fuel into a red-hot cat converter is a really bad idea.

Do you own one of these?

 

Ah! Sudden spark failure. Yes, I suppose that could happen. I didn't think of that, (why I asked), but wouldn't you almost immediately notice the drop in power and just shut off, or is that not quick enough?

No, I have a Mondial t. I have driven it on 4 cylinders, but it is smart enough to shut down that side's fuel pump.

 

Therein lies the problem - you're making blanket statements about an automotive system you don't have, have never maintained, and perhaps know very-little about since yours does not operate as OURS does.....

 

Norwood sells a pretty reasonably priced single distributor upgrade.

I believe in personal responsibility. Back in the day when we had Neanderthal catalysts forced upon us by Big Papa, I was right there with the "test tube". But that was then and this is now. Modern catalysts are a god send. To ignore that and fiddle around with a half-baked setup as an excuse to not be responsible for the output of *your* car's tailpipe is simply inexcusable. If everyone just cleaned up after themselves the world would be so much nicer. Well, I can't make anyone clean up after themselves, but I am damn sure going to speak up about it once in a while. Meanwhile, please, spare me the lame justifications.

Here's what I really don't get: One year in now, and I am astonished to discover that half the fun of owning a Ferrari for me is how readily I can fine tune its details to bring out the best of it, and eliminate the rough edges. (With other cars it's like trying to sweep up the beach - with a Ferrari it's like all you have to do is a little wet sanding and, BANG! it's done.) Now, in 2009, the only cars whose owners can reasonably claim an exemption from the personal responsibility of having a cat or two and a well-tuned engine to go with are the true antiques that are only driven on occasion. 3X8s are not antiques, they are some of the finest sports cars ever made, should be driven regularly, and should shine with pride of ownership, not limp along with a hillbilly tune up and a lead lined exhaust system.

I hope no one thinks that I am trying to say that if someone has a problem or concern, now, then they should not take the precaution of disconnecting their cats. But to regard that as a permanent solution instead of a temporary crutch is where I stop following along. I know that if I was in that situation, the day I hooked my cats back up with the confidence that I need not worry about them any more is something that I would be eagerly anticipating as a real milestone!