Tubi or K&N Air Filter for 1999 355 F1?

Todd- long time no talk- I haven't been on the boards as much!

Anyway, I bought a carbon fiber intake box cover (larger opening than stock) and K&N for my 911 a couple of years ago, but then read on the Porsche forums where people were having issues with the K&N oil getting on mass airflow sensors and such- whether it was from the K&N filter when it was new out of the box, or after the filter was cleaned and over re-oiled by the owner, I don't know. I decided to not take the chance and never put the K&N in- figured it wouldn't make any noticable performance difference, and just kept the stock filter in- didn't want any issues. The carbon airbox cover does make a nice sound difference in the 911 though, but no 355...

I don't know if this is different with the 355s due to the longer length of the intake hose vs. my 911, but just adding my .02

-Andrew

 

Step 1-I have put the Tubi exhaust and K&N filters on my 99 355 (this was the 1st step I took as a modification)there was a noticable tone difference the trademark sound that is preffered is this exhaust(Tubi!!).There was not a significant power difference(any significant claims are based on a power adder application ;supercharged turboe'd) although the Tubi is more freeflowing hense runs the engine bay "slightly" cooler (any little bit cooler helps in these cars).

Step 2-was Tubi headers and bypass pipes "test pipes" .....the sound is simply PHENOMINAL.At this point I definatly felt a significant difference in power and snappy response as well as "MUCH" cooler engine bay.

I further added a couple of factory looking very high flow and low profile thermostatically controlled fans to aid in when engine bay gets hot ,they are especially helpfull when the engine is shut off and it heat sinks further to extend the life of all belts ans hoses.

The set-up above I have run on 1999' MY355 which now has 56,000 miles on the ODO and no issues.

PS... if you still have the cats on the car the history of mine were 1 was smoked @ 26k the other @ 50K they are rebuildable "do not get misled into factory OEM" 5-6k for both!!
NOTE... before you do ever even pay for a rebuild of the cats if need be check because emissions warrentee demands 100k mile warrentee.
hope this is helpful info........



GOOD LUCK
MY355

 

Bill,

Long time no talk, I finally got MY99 6spd last year. My question is how you put the test pipe in there and still able to escape the dreaded CEL / SDL...? I wired the bypass valve early this year, sounded good for a couple days, then the CEL / SDL came on I ended up unwired the dam thing. I wanna to replace the cats too with test pipes but still not figure out how! Glad to see your GTS still getting her exercise!

Ken

 

Congrats w/ your MY99

CEL/SDL??
If what your speaking of is the computer throwing a code ,there is an inline plug and play part that fools the computer and tells it everything @ the O2 sensors is just fine.The part costs 50.00/side you'll need 2 "total 100.00"
A google search for "02 sensor bypass" will uncover a few co's that build this little electronic tool.

If what your speaking of is emmissions test ,well mysteriously the cats appear in place of test pipes for about 3 days every two years.Ironically it always seems to be around the time the emmission test is due............

MY355

 

Sorry to steal your thread, I do have K&N drop in. The difference is not noticeable. And it would not trigger any check engine light.

 

Your correct an air filter would not trigger but what I was saying "does" is the bypass "test pipes".I thought thats what I said maybe I missed something.
Anyway.........
MY355

 

Go with the BMC CDA, see threads by Stephens et alon these. I believe the model number is CDA 85-150 as used by the 550M.
You will be very pleased.
Ron

 

Todd- just got back on f-chat (already Tuesday night). I'm going to be out of town on business tomorrow, returning Friday afternoon...I'll give you a call if I get home at a decent time to see if you're around....I want to make sure the lift can lift a 355 as well as the 911 The wife and I drove by the house the other week, but no one home...(well, the garage doors were shut anyway, and were just out for a drive)

 

I know this thread is old, but I use the search feature and didn't want to start a new thread... Looking for anyone who has K&N filters...Thoughts??

 

I had one on my 78 308GTS and also on my 87 328GTS, but have not bothered on the 355. Also, neither of the previous cars had a MAF to get fouled. I hear the hot film sensor on the 355 MAF can get messed up with the oil on the K&N...perhaps that is internet "urban legend", but figure it is not worth messing with for so little benefit. All I really noticed on my two previous Ferraris was more intake noise... (note post #6)

 

It's real, not a legend. It's in the chevy tech bulletins. The problem is not so much the filter but the oil on the filter, specifically too much. GM does not void the warrentee if you have one of these filters but if the tech finds oil inside the hose coming from the filter the customer is charged for the sensors and cleaning.

I am not a big fan of K&N filters. I don't think they filter all that well for street cars and if you talk to people that spend a lot of time on the dyno they will tell you in many cases no improvment or in some cases hp goes down.

As far as getting rid of the O2 sensors I can't see any good reason to not let the computer control the mixture?

 

So you guys recommend just staying with the stock filters?

 

The problem arises when people try to re-oil their filters and use way too much. If you use a K&N (they are pre-oiled), just toss it into the garbage after its used and buy a new one. For $50 (or whatever), it's much cheaper than a new MAF.

 

You can always get this...
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Oh wait.... 99 right?
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I made a dyno run with and without the GruppeM air Ram system (5.2 Motronic).
We measured a gain in power from 10 to 15 HP nearly all over the rpm-range.

 

Which version, 2.7 or 5.2 Motronic?

 

I bet for the cost of that setup---I could buy a new liver..

 

I saw one on Ebay yesterday, figured it was OK to drink tonight.

 

After just buying my 1995 F355, I discovered it has K&N Filters (checking out hard cold starts). The MAF's and screens were not gummed up alto I sprayed generously with starter fluid ti check for residue - none. Starting problem is fuel draining back so I turned ignition and waited 30 seconds before cranking. Started on second crank. My mechanic recommended to replace with OEM paper filters as the K&N filter oil may interfere with the MAF sensors. Not worth the risk

 

While some swear by them, frankly the K&N and the other "foam type" air filters aren't good air filters at all.

The ISO 5011 Standard (formerly SAE J726) test is a measure of air filtration performance and K&N won't advertise their results based on that standard test. The reason for that is their performance is pretty poor. They offer a bit less restriction when clean, but they clog up faster and passs more dirt all the time than a good paper filter. K&N is selling big bunches of filters and they can afford to do the testing and they probably have, but they won't publish and results and they sure don't make any claims that they filter any better than the OE filter or they would end up with an FTC lawsuit, so they just keep their mouths shut and count their money. Here is a link to a proper test that was done to compare K&N's with paper filters and the results are pretty eye opening.....

http://home.stny.rr.com/jbplock/ISO5011/SPICER.htm

If you have a car that you believe is an investment, you wouldn't want to bother with a K&N. Generally they have a bit more induction noise so people think they "feel' faster but the restriction of a modern paper filter is so low that giving up the filtration performance isn't worth it. If you are running a Honda Civic in an autocross and a thousandth of a second is a big deal, go for it, but if you don't want sticking rings and excessive bore wear I'd skip the K&N....

 

Amen! 1+
We run a KN filter on one of the race cars that looks like a stock round air filter for a muscle car only it has filter material on the top so you don't use the round metal hubcap on top and the theory is air comes in the top as well as the sides. K&N claims HP increse but I know someone that has a dyno and they were getting a loss instead of an increase. Apparently some sort of turbulance problem and when called one of the K&N tech people admited the HP increase was only seen on the thicker models over 4 inches high like the sprint cars use. We still use it on our car only becuase we have a forced air system that forces air through the top of the filter.