That is correct.

And it is a fact that the hoses on an X-51 and the standard 997s are different sizes in Dia, length, and shape.

 

+1

I have X51, but cant install it(( TB is less that X51 dia. Has anuone idia how to install it withouy major modifications?
Maybe someone find aftermarket hose to fit X51 airbox with standart TB?

Thanx,
Alex

 

here is my write up from renntech.org

After much study I jumped in and did the X-51 airbox.

Cutting the hole was a major PITA. A couple of pointers get the X-51 upgrade TSB. Take off the painted portion of the Spoiler, it is only 4 screws and very easy to do. The cutout pattern in the TSB is a little small even if you print it with no margins. I enlarged it 102% and it worked fine.

Installing the Oil Fill pipe is also a major PITA. In addition to removing the ALternator which is difficult as previousily discussed I also removed the plenum which gave me more room to work. Removing and reinstalling this is easy as I had done before with the RSS Plenum.

As far as Adapters I bought the following from BoostController.com and after cutting it length with an exacto blade it worked perfectly;


Silicone Straight Hose, SHORT - 2 inch length #ASCSHS2-X

Size - 3.25 inch ID (add 5.00)

Color - Black

The dealer who sold me the parts also recommended the following; Hoover Vacuum belt for the Self Propelled WindTunnel is a perfect fit (part number 38528-035).

I also had to trim a little bit off the edge of the x-51 Boot to get it to fit correctly on the TB. I also had to push the clamp on in that same area with a screw driver.

It was a very challenging project but I am glad I did not only for the looks but the performance gains mentioned earlier.

RSS also has a modified TB which I added at the same time. They basically improved the aerodynamics by machining the entrance to more of a point for a venturi effect and machining the Shaft so air flows around it better.

 

+1 this setup... my car is stock except for a Fabspeed CAI and a BMC Filter. Once I put this combo in my car immediately felt different. I thought my S felt sluggish, the CAI makes a AWESOME sound someone thought I had a exhaust system on my car the other day and the BMC makes some Hp. So its a sweet combo for the price. I strongly recommend it

 

Thnx!
Do you have photos of parts and setup install?

 

Send me a PM with your e-mail and I will pull what pics I have together and send them to you.

 

I recently put the Fabspeed CAI on my 2008 997 Carrera - cap and hose. I also did a little refresher on cavity resonance design, from my old acoustics courses. I think that cavity is designed to damp out some lower frequencies when you're on the throttle and getting a good airflow thru there. Also, the smooth hose reduces pressure losses and will get you a slightly higher static pressure at throttle body inlet. Other observations:

1. the engine basically sounds the same at idle as stock.
2. I have noticed better throttle response on throttle blips and the intake/exhaust sound has more low frequency content, resulting in a bit louder sound, probably at least 3dBA since that's what the human ear can really recognize anyway.
3. I have noticed the car is a bit more quick (maybe 0.1-0.2 sec quicker to 60).
3. I wanted something inexpensive, and really for $225 it does 3 things: better sound, better throttle, and I've also noticed a little bit better fuel economy, probably due to a little higher pressure at engine inlet.

It's a simple fix but I'm all for it. The sound is good enough that I'm sticking w/ stock exhaust, for now.

 

Your a prime candidate for the plenum. You should get 40Hp you can feel out of that too.

 

Did you keep the stock air filter or replace it?

 

I just kept the stock air filter. I'll replace it when it's coming due, probably next summer. My car has 14k miles. From what I hear the BMC gives better airflow. With that, the sound may improve just a tad more.

None of the improvements (fuel econ, throttle response, and sound) from the perf intake were huge, but all were noticeable and an improvement to the driving experience. Note that I don't think it's a true "cold" air intake, because nothing is really re-located, but I'll call it a performance intake, and for the price the improvements are quite good. Hope this helps.
____________
2008 C2, Black/black, 6-spd, Nav-TV, PCM w/ Nav, XM, Pwr seat pkg, Xenon, Fabspeed CAI, 'S' silver trim, CF trim

 

I dont think anything needs to be changed to make it a cold air intake. The snorkel is drawing in fresh air from outside the engine bay, so I would consider that cold air....vs. drawing in hot air from inside the engine bay.

 

Ok, I'm new to this forum and a new Porsche 997 owner, but to me it seems simply illogical that Porsche engineers would not create this ridiculously simple smooth tube instead if it improved performance. Why wouldn't some of the best engineers in the world know how to make their engine perform the best? It seems a bit ridiculous to think this smooth plastic piece would make a Porsche faster. I may be wrong, but it sounds like a marketing gimmick to me. Sound does not equate to speed.

 

Congratulations and welcome on your 1st post. What you will quickly learn is that for some almost inexplicabe reason Porshce (and many others too) leave a lot of little things on the table; some you can purchase from them as obscenely expensive options, others are availlable from the various tuners and aftermarket hustlers. While I'm tempted to agree with you on the Fabspeed tube, their literature and purported dyno results speak otherwise.

 

You're gonna be disappointed if you think that the pinnacle of proper engineering decisions was bestowed upon your porsche. If you look close enough, there is cost cutting and/or compromise everywhere. Ask yourself, why is there no LSD on cars of this ilk? Why is the shift throw so long? What does that center muffler do? There are lots of little spaces where things can be easily improved with the aftermarket.
Anyway, You will love your 911 and rightly so, but don't start your ownership with a glass of kool-aid!
And Welcome to the Board!!!!!

 

JohnM, I would agree they probably make compromises for cost cutting reasons and other emission reasons, but to me and in my opinion, this piece of plastic tubing couldn't be one of them. I mean how much does it cost to make one smooth piece of tubing instead of a rippled one? Didn't Porsche see what people were doing in the aftermarket and just make them this way so they can charge for it? I can see they may add other cats or mufflers for sound or environmental crap, but this? I don't think that argument for this particular piece of equipment is valid. To each his/her own, but that fabspeed thing seems like marketing only. Especially, when you consider the variation in dyno results can be probably + or - some % on each run. This could easily account for any increase in HP for a particular run to me. I think if the sound is better and people like that sound, that's all we should expect to actually change with a smooth versus rippled 12 inch long piece of plastic, but that is just my new, inexperienced, but possibly more objective opinion as a newbie Porsche owner.