Retrofit X51 Power Kit Airbox into stock 997C4S

[dndodd]

...well heard back from my local Porsche Center in Cardiff, UK and the comlpete X51 'Air Cleaner' costs £638 GBP and that doesn't include 'Air Box' (inlet pipe) or extra gasket for lid and X51 oil filler pipe. Cutting the lid seems no biggy with provided template but that oil filler pipe looks a right bugga to remove and change and I know someone on here mentioned about removing the alternator but that looks pretty complex for a D.I.Y.'er?

They did mention some discout on the parts but not sure what type of gains are to be had just for fitting this alone without the engine mods. Had PSE installed after I took the car so enjouying the benefits of that already.

Watch this space I guess...

D

well i finished my install , of the x51 intake and the headers. the alternator removal was a pain, it just would not come out, but once again the forum helped me out, the bushing on the alternator gets rusted, so it wont budge, but few bang with the hammer on the bolt it loosened up the bushing an the alternator came righ out. oil filler pipe swap was a breeze. just be patient. impresse witht the results, car now has a better throttle respones, and slightly quicker.

next is the 20 mm euro sports supsension. I have assembled all the suspension outside the car, just have to swap it now.

Did you need to replace the MAF stock wiring harness to X51 when installing? Some people report that the standard wiring is to short.

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.

Edited December 9, 2007 by dndodd

[AGUIRREMoore]

just wanna share I just installed an X-51 air box. I used a Hoover vacuum belt as a spacer. I still need to cut the deck lid.

__________________________

Edited July 8, 2008 by Loren
Removed commercial signature

[shocky]

...well heard back from my local Porsche Center in Cardiff, UK and the comlpete X51 'Air Cleaner' costs £638 GBP and that doesn't include 'Air Box' (inlet pipe) or extra gasket for lid and X51 oil filler pipe. Cutting the lid seems no biggy with provided template but that oil filler pipe looks a right bugga to remove and change and I know someone on here mentioned about removing the alternator but that looks pretty complex for a D.I.Y.'er?

They did mention some discout on the parts but not sure what type of gains are to be had just for fitting this alone without the engine mods. Had PSE installed after I took the car so enjouying the benefits of that already.

Watch this space I guess...

D

well i finished my install , of the x51 intake and the headers. the alternator removal was a pain, it just would not come out, but once again the forum helped me out, the bushing on the alternator gets rusted, so it wont budge, but few bang with the hammer on the bolt it loosened up the bushing an the alternator came righ out. oil filler pipe swap was a breeze. just be patient. impresse witht the results, car now has a better throttle respones, and slightly quicker.

next is the 20 mm euro sports supsension. I have assembled all the suspension outside the car, just have to swap it now.

Did you need to replace the MAF stock wiring harness to X51 when installing? Some people report that the standard wiring is to short.

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.

[shocky]

Do you have any pictures of this mod?

Thanks

John

[Gundo]

This is what it looks like.

[shocky]

This is what it looks like.

Thanks for the picture.

John

[mapoune]

Hello Everyone,

I've also made the changes: X51 Airbox, cuttings etc ... I saw a few post on adapting the X51 TB. It will not fit the standard Plenum T. And I can confirm it now. I manage to send my RSS IPD Plenum back so they can adapt the X51 TB. Apparently Greg (RSS) confirms that it is possible and will be in their catalog soon. Of course, you need to get the ECU Remap for the extra intake air. The MAF diameter between the stock an X51 airbox is the same so the flow will increase with the mods and can be out of range.

Cheers.

[David4315]

This is one of the most detailed threads on a very desireable upgrade I think I have seen and is a no brainer for performance improvement. Thanks to all for the help. I found this parts list on 6Speed from a contributer:

Intake Manifolds: #997.110.115.40 X2

Throttle Body: #997.605.116.00

Distributor Pipe: 997.110.416.40

Rubber Sleeve: 997.110.685.40 X2

Hose Clamp: 997.512.694.00 X4

Electric Line (tank vent line extension): 997.607.130.00

Tank Vent Line Support: 997.110.429.40

Support for throttle body: 997.110.423.40

Support: 997.110.433.40

Tank ventline including Valve: 997.110.129.40

Tank Ventline: 997.110.127.40

It sure would be nice if Porsche just had a simple X-51 CAI including appropriate ECU remap so we could all quit guessing and jerry-rigging our poor cars with Hoover drive belts of all things. When I was deployed in Iraq I first heard the term "hillbilly armor," but I never thought it would apply to my Porsche.

[ALLSPEED]

Do you think one could adapt it to fit a 996?

[phillipj]

AllSpeed,

Its the same process. The 996 and 997-1 have the same basic engine. I was told by the folks at Suncoast that the X-51 box will fit but you will have to make the same modifications. Do a search here. I think there is a thread. Also if you call Suncaost they are very "mod friendly" and can be of help with ordering what you need.

[MichaelGCypher]

I do not know why everyone is saying the Air Box Outlet Diameter near MAF is the same for the 997.1 S Stock Airbox and 997.1 X51 Airbox. It's not - I measures with callipers...

X51 : 90.6 mm
Old stock  : 85.8 mm
.....It's a 4.8mm difference. 

This means you may need a tune if you upgrade due to improper readings by MAF. Some of the top tuners for Porsche 997 said you should tune it when I asked.