Hey guys,

I bought the car with a LTW Flywheel and some kind of aftermarket clutch. Even after I got the clutch accumulator replaced, it still seemed really touchy and would easily stall unless I was VERY careful or over-reved like someone who doesn't know how to drive stick.

I always blamed this behavior on my LTW Flywheel.

HOWEVER, I swapped my air filter yesterday and the driving experience is totally different now. It generates enough power with almost no gas to get the car going preventing the sudden very quick drop in RPMs. This means I can drive it like a NORMAL stick.

So much for buying a CPO vehicle eh?

For those of you experiencing drivability problems, for 70 bucks and 30 minutes of your time you can try this before you go for the GT2 clutch conversion or something. Maybe my filter was just ridiculously dirty or something, but it was a noticeable improvement. The idle is way less lumpy now as well. Disclaimer: This might be a bigger issue because I'm at altitude or something.

Oh, and for those who will ask: I just got another OEM filter from suncoast. None of this MAF destroying K&N stuff.

 

Yes, The Mile-high club suffers especially when you are talking about turbo's and that is why, in turbo aircraft ( generally) they have something called a turbo normalizer that automatically maintains a certain altitude in the ECU so this does not happen. It is amazing the difference the altitude makes. as a pilot with a turbo aircraft I can attest to that.

 

That's pretty cool...not sure I've ever heard that mentioned about the 996TT. I'll file that one away into memory, and I'm glad to hear it really helped you out.

 

Hey, Just for the record I have had a K+N filter in for 25,000 miles with the same MAF...

 

How dirty was your old one? Did you hook the MAF back up when you re-installed?

Just curious...

 

The old filter was pretty dirty. It wasn't like pure black or anything, but if you tapped it on the ground, dust would go everywhere. I have to imagine that was blocking some airflow.

I drove it for about 1.5 hours today - no weird stutters when the engine was cold...really nice.

I did hook the MAF back up with the reinstall but I admit, it never went "click" when I pushed it back in. I doubt it'll pop off, but that was slightly disconcerting to me.

 

I often recommended people just change stock paper filters at 2x the recommended frequency to achieve a higher overall airflow/performance. Any filter will reduce flow over time as it gets loaded with dust/particles...so by only using the filter during the first half of it's life, you will- effectively- running a higher efficiency over time.

Without using a crappy aftermarket filter with low filtering performance (ie K&N)

A

 

[QUOTE=ard;3560782]I often recommended people just change stock paper filters at 2x the recommended frequency to achieve a higher overall airflow/performance. Any filter will reduce flow over time as it gets loaded with dust/particles...so by only using the filter during the first half of it's life, you will- effectively- running a higher efficiency over time.

Without using a crappy aftermarket filter with low filtering performance (ie K&N)

A[/QUOTE
Sorry to disagree with you about K+N filters
What do you base your findings on?
Only problems I have seen is when others over oil or clean them wrong.
I have used them and inspected intake tracks,cylinder walls and have never saw any damage due to bad filtering.On my dynoing experience, never saw a decrease in power either.
To each his own.Just sharing MY findings..

 

I base my findings on published ISO5011 filtration studies showing K&N are far inferior to OE/OEM filters.

http://www.google.com/url?sa=t&rct=j&q=iso+tests+air+filter+spicer&sourc e=web&cd=1&ved=0CLYEEBYwAA&url=http%3A%2F%2Fhome.r oadrunner.com%2F~jbplock%2FISO5011%2FSPICER.htm&ei =hTzOT5HWGYHq9ATZ4O2eCw&usg=AFQjCNHa39TcMgVKEbdSMx lTiRCWT-dunQ


These tests were devastating to K&N, and as a result K&N has cooked up their own tests and spends money ensuring that Google results place their pages first. Do a search, their pages come up first.

But you will find that K&N selects the results they publish very carefully, with no real comparisons to other filters, and they fail to show any damaging results (like how much dirt they let in over time as they fail to load up- 'loading up' being a 'good' thing since it means the dirt isnt getting in!)

Oh, you inspected the intake tracks and cylinder walls? Last thing I'd worry about. Run UOAs over time with paper and K&N and let me know if you silicas and wear metals increase with lower intake filtration.

Automotive Engineering is, well, engineering...it is not "I tried it and it was great"... so I like to base my decisions on data.


YMMV. At the end of the day, who cares if the motor wears out a bit faster, right? Seriously. Probably not material and nobody will ever be able to prove it.

A

 

my own personal take on k&n and bmc oiled filters, is that if they were nearly as potentially problematic as people "claim" them to be, reputable tuners and track rats, and owners alike, wouldn't continue to use them. maf's get blown on these cars, regardless of what air filter we use. ymmv, but i don't believe the hype.

 

I have not had a problem in all my gearhead motor building days, carbureted motors,with K+Ns
I do not go off roading to encounter sandy conditions
I feel confidenant that they dont let major particles in the motor to cause oil contamination to wear out cylinder walls,valve seat surfaces.
Maybe they might not be the best for newer fuel injections?

 

Like I said, it isnt the intake (cyl walls, valve seats) that worries me-

It is dirt in the oil accelerating wear throughout the motor! Bearings, every lubricated surface....

http://papers.sae.org/881825/

"blowing out mafs" and fouling mafs are different things.... What is OK for a race car isn't OK all cars. Reputable tuners and track rats really don't have a long term view of this stuff.

Data and engineering say one thing- and the entire aftermarket performance industry works hard to get you to not listen.

The 'hype' is that people need 'performance filters'.... especially on a FI motor!

 

And Like I said,I have had no MAF issues in 25,000 miles with it plus its the original MAF....My engine is tight,burns less then what normal oil consumption says and has been on the Dyno more times then I can count plus makes good power for what it is..
I know how to service a K+N filter correctly which may count for this??
All my trucks that I have owned past/ present,all my motorcycles and other cars all ran K+N...
It may not be the best for some reasons others believe or know But I wouldnt say its the worse either..IMO..

 

Oh, I will add that the most common issue with oiled filters is not a wholesale "fouling" of the maf with hard failures, codes or a 'blown maf" (the latter is exceedingly rare), but rather a slight fouling of the maf element such that, over time, the maf becomes coated with a hard oxide that will not clean off with solvent- this layer insulates the element causing an apparent lower airflow value, and results in rich running- as a result the long term fuel trims will be slightly off, and the DME will use the O2s to adjust... and just a bit off on power. Much more of an issue on NA motors.

 

John- Even with perfect application of oil and zero MAF issues..... my beef is filtration performance.... NOT OIL FOULING.

Lets say it is a personal choice. Good?



A