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Posted by: Jon H. Jan 22 2014, 07:11 PM

Will these affect the performance of a stock FI 2.0L engine negatively in any way?

Regards'

Jon

Posted by: Elliot Cannon Jan 22 2014, 07:13 PM

K&N. One of Capn' Krustys' faves.

Posted by: Jon H. Jan 22 2014, 07:44 PM

Yeah I know the K&N battle, but does anybody run these things? I'm more or less questioning the vacuum line hook ups and vacuum effecting FI performance. Not so much if K&N is a good air filter.

Jon

Posted by: Elliot Cannon Jan 22 2014, 08:36 PM

I used them on my 3.2 (yellow zonker) and I use them on my other car with Webers. Work fine for me. I'm sure others will disagree. But then again, I use high temp silicone to seal and secure my push rod tubes so what the hell do I know?

Posted by: Woody Jan 22 2014, 09:15 PM

The only time I would use a K&N is when a paper filter won't fit an application. K&Ns allow bunches more air in but only because they filter less which also means they let in trash. If a K&N is your only option make sure you clean it regularly and keep it oiled. If its on a newer car that runs a MAF sensor a K&N will trash it in short order.

Posted by: 3d914 Jan 22 2014, 10:09 PM

Jon,

Any of the lines forward of the throttle body are not vacuum - they're open to atmosphere. They should not affect FI performance. The only lines that can are those after the throttle valve.

Posted by: boxsterfan Jan 22 2014, 10:33 PM

Aahhhh, the age old question of getting better air intake into the 914 engine.

I always wonder if you could get air piped in all the way from the front of the car.

Posted by: MATTYLITE Jan 22 2014, 10:49 PM

We built a single intake system, and a dual intake system (pictured) for this application. This system has been proven on the track with multiple Porsche Owners Club class wins and perfect for the street as well.

https://imageshack.com/i/0sssgvj
https://imageshack.com/i/5ncs9hj
https://imageshack.com/i/0dozd5j
https://imageshack.com/i/5nc7zkj

Posted by: Dave_Darling Jan 23 2014, 10:07 AM

The FI doesn't really care exactly where its lines are hooked up. It just needs specific hoses to either be hooked to manifold vacuum, or to ambient-pressure (filtered) air. So as long as you hook up the hoses that used to go to the air cleaner to something "upstream" of the throttle body, you're fine.

(The exceptions to only manifold vacuum or ambient air are the lines from the throttle body to the distributor dashpot. But those don't enter into this discussion anyway.)

--DD

Posted by: Socalandy Jan 23 2014, 11:01 AM

I ran K&N's on my 72 with 44 Webers and had a lot of issues with clogged idle jets so I added the K&N pre-chargers and that solved my issues. I'm going the same route for my -6


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Posted by: Jon H. Jan 23 2014, 01:12 PM

Thanks for the replies. Not sure though if I will make the purchase. After all, it really only looks better then the OEM filter housing.

Jon