Retrofit X51 Power Kit Airbox into stock 997C4S

[cgng30]

The X51 throttle body does fit, according to RSS here in the states who manafacturers a new intake distribution tube said the X51 throttle body will fit the non X51 intake.

Dave

I am not clear, if the x51 throttle body(which is larger then the stock one) does fit the non x51 intake (which is smaller then the x51 intake manifold, then how does the inside diameteres match up

x51 ID verses the non z51 intake manifold ID , ?/ or are they the same.

Ronnie

Sorry Ronnie didn't see this..you have to remember that the throttle body doesn't connect to the intake manifold directly. It connects to a plastic intake distribution tube commonly called the "plenum", this is the part that RSS has done through the aftermarket. As far as the X51 throttle body ID vs. this part, well this is the million $ question. Whats nice about the factory piece being plastic you can probably grind it down to gasket match this and you could probalby do it with the RSS aluminum part as well. I was told by RSS that the X51 TB does fit. Haven't seen this myself though...(my disclaimer :D)

Dave

thanks dave , i really meant the plenul, the irony is i already fitted the rss plenum in the car. I also have the airbox , filler tube, sitting in my house. I was thinking about just getting a silicone transition tube from the throttle body to air inlet hose. i am not sure how much the throttle body is . have you ordered your stuff yet

ronnie

Hey Ronnie, not yet. Do you have the template for cutting the lower deck for the 2nd airtube??

I saw your post regarding the oil filler tube and the alternator. I will see if I can find out how to do this. I am leaving to Japan for a few weeks, and I will probably order it when I get back.

Dave

ya the dealer shipped it with the aie box, but unfortunately the scale is incorrect. will keep you posted

ronnie

[Vman]

The X51 throttle body does fit, according to RSS here in the states who manafacturers a new intake distribution tube said the X51 throttle body will fit the non X51 intake.

Dave

I am not clear, if the x51 throttle body(which is larger then the stock one) does fit the non x51 intake (which is smaller then the x51 intake manifold, then how does the inside diameteres match up

x51 ID verses the non z51 intake manifold ID , ?/ or are they the same.

Ronnie

Sorry Ronnie didn't see this..you have to remember that the throttle body doesn't connect to the intake manifold directly. It connects to a plastic intake distribution tube commonly called the "plenum", this is the part that RSS has done through the aftermarket. As far as the X51 throttle body ID vs. this part, well this is the million $ question. Whats nice about the factory piece being plastic you can probably grind it down to gasket match this and you could probalby do it with the RSS aluminum part as well. I was told by RSS that the X51 TB does fit. Haven't seen this myself though...(my disclaimer :D)

Dave

thanks dave , i really meant the plenul, the irony is i already fitted the rss plenum in the car. I also have the airbox , filler tube, sitting in my house. I was thinking about just getting a silicone transition tube from the throttle body to air inlet hose. i am not sure how much the throttle body is . have you ordered your stuff yet

ronnie

Hey Ronnie, not yet. Do you have the template for cutting the lower deck for the 2nd airtube??

I saw your post regarding the oil filler tube and the alternator. I will see if I can find out how to do this. I am leaving to Japan for a few weeks, and I will probably order it when I get back.

Dave

ya the dealer shipped it with the aie box, but unfortunately the scale is incorrect. will keep you posted

ronnie

I just sent you a PM, but in case you don't check it......... Did you measure the difference, if any between the diameter of the stock 3.8 airbox where the maf is inserted and your new x51 airbox? Also, one would need to measure how far the MAF extends into each intake tube and make sure it was the same. If the two internal diameters are not the same you will be getting a bad MAF reading causing your car to run too lean or too rich. If the intake diameter has increased the MAF would read low and the ECU would respond by running too lean (may not good for engine longevity but can make more power and could also be why at startup you are running a bit rough as the stock program usually tries to run the car rich until it is warm).I am trying to get data on this as I am on the fence on doing an X51 airbox or EVOMS one for my 3.8 x51, so please let me know if you have done the calculations.

Edited July 29, 2007 by Vman

[Vman]

The X51 throttle body does fit, according to RSS here in the states who manafacturers a new intake distribution tube said the X51 throttle body will fit the non X51 intake.

Dave

I am not clear, if the x51 throttle body(which is larger then the stock one) does fit the non x51 intake (which is smaller then the x51 intake manifold, then how does the inside diameteres match up

x51 ID verses the non z51 intake manifold ID , ?/ or are they the same.

Ronnie

Sorry Ronnie didn't see this..you have to remember that the throttle body doesn't connect to the intake manifold directly. It connects to a plastic intake distribution tube commonly called the "plenum", this is the part that RSS has done through the aftermarket. As far as the X51 throttle body ID vs. this part, well this is the million $ question. Whats nice about the factory piece being plastic you can probably grind it down to gasket match this and you could probalby do it with the RSS aluminum part as well. I was told by RSS that the X51 TB does fit. Haven't seen this myself though...(my disclaimer :D)

Dave

thanks dave , i really meant the plenul, the irony is i already fitted the rss plenum in the car. I also have the airbox , filler tube, sitting in my house. I was thinking about just getting a silicone transition tube from the throttle body to air inlet hose. i am not sure how much the throttle body is . have you ordered your stuff yet

ronnie

Hey Ronnie, not yet. Do you have the template for cutting the lower deck for the 2nd airtube??

I saw your post regarding the oil filler tube and the alternator. I will see if I can find out how to do this. I am leaving to Japan for a few weeks, and I will probably order it when I get back.

Dave

ya the dealer shipped it with the aie box, but unfortunately the scale is incorrect. will keep you posted

ronnie

I just sent you a PM, but in case you don't check it......... Did you measure the difference, if any between the diameter of the stock 3.8 airbox where the maf is inserted and your new x51 airbox? Also, one would need to measure how far the MAF extends into each intake tube and make sure it was the same. If the two internal diameters are not the same you will be getting a bad MAF reading causing your car to run too lean or too rich. If the intake diameter has increased the MAF would read low and the ECU would respond by running too lean (may not good for engine longevity but can make more power and could also be why at startup you are running a bit rough as the stock program usually tries to run the car rich until it is warm).I am trying to get data on this as I am on the fence on doing an X51 airbox or EVOMS one for my 3.8 x51, so please let me know if you have done the calculations.

Just confirmed today that the intake at the point of the MAF sensor is the same inner diameter for 996/997 and 997 x51 intakes. The difference in the X51 intake is that the factory one has two air snorkels and a bigger internal diameter hose to deal with the bigger inner diameter of the X51 throttle body. Also, 3.8 non x51 cars running x51 airboxes may be getting a rough idle because the tubing diameter differential.

[Dave07997S]

The X51 throttle body does fit, according to RSS here in the states who manafacturers a new intake distribution tube said the X51 throttle body will fit the non X51 intake.

Dave

I am not clear, if the x51 throttle body(which is larger then the stock one) does fit the non x51 intake (which is smaller then the x51 intake manifold, then how does the inside diameteres match up

x51 ID verses the non z51 intake manifold ID , ?/ or are they the same.

Ronnie

Sorry Ronnie didn't see this..you have to remember that the throttle body doesn't connect to the intake manifold directly. It connects to a plastic intake distribution tube commonly called the "plenum", this is the part that RSS has done through the aftermarket. As far as the X51 throttle body ID vs. this part, well this is the million $ question. Whats nice about the factory piece being plastic you can probably grind it down to gasket match this and you could probalby do it with the RSS aluminum part as well. I was told by RSS that the X51 TB does fit. Haven't seen this myself though...(my disclaimer :D)

Dave

thanks dave , i really meant the plenul, the irony is i already fitted the rss plenum in the car. I also have the airbox , filler tube, sitting in my house. I was thinking about just getting a silicone transition tube from the throttle body to air inlet hose. i am not sure how much the throttle body is . have you ordered your stuff yet

ronnie

Hey Ronnie, not yet. Do you have the template for cutting the lower deck for the 2nd airtube??

I saw your post regarding the oil filler tube and the alternator. I will see if I can find out how to do this. I am leaving to Japan for a few weeks, and I will probably order it when I get back.

Dave

ya the dealer shipped it with the aie box, but unfortunately the scale is incorrect. will keep you posted

ronnie

I just sent you a PM, but in case you don't check it......... Did you measure the difference, if any between the diameter of the stock 3.8 airbox where the maf is inserted and your new x51 airbox? Also, one would need to measure how far the MAF extends into each intake tube and make sure it was the same. If the two internal diameters are not the same you will be getting a bad MAF reading causing your car to run too lean or too rich. If the intake diameter has increased the MAF would read low and the ECU would respond by running too lean (may not good for engine longevity but can make more power and could also be why at startup you are running a bit rough as the stock program usually tries to run the car rich until it is warm).I am trying to get data on this as I am on the fence on doing an X51 airbox or EVOMS one for my 3.8 x51, so please let me know if you have done the calculations.

Just confirmed today that the intake at the point of the MAF sensor is the same inner diameter for 996/997 and 997 x51 intakes. The difference in the X51 intake is that the factory one has two air snorkels and a bigger internal diameter hose to deal with the bigger inner diameter of the X51 throttle body. Also, 3.8 non x51 cars running x51 airboxes may be getting a rough idle because the tubing diameter differential.

Thanks for the PM...I have talked to 2 people who have done this and they didn't complain of any rough idle.

Dave

[V6 TT]

...hey ianwallwork so did you figure out if the X51 throttle body, box, oil filler tube, etc. were a direct fit to a non X51 997 C2S as I'd like some part numbers and get it ordered?

Cheers

Dean

Edited August 7, 2007 by V6 TT

[V6 TT]

...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

Edited August 9, 2007 by V6 TT

[george_k]

Can one of you gents be kind enough to post the parts numbers for the X51 box, seals, etc.

How bad is the fit of the stock oil filler pipe if left alone?

Thanks Much,

George

[george_k]

Or PM them to me.

Thanks.

[dndodd]

Or PM them to me.

Thanks.

If no one responds with the part #'s you can look and the at the link below and find the x-51 parts.

http://www.boardwalkag.com/catalog/catalogue_content_en.htm

[baptist]

Any updates on this?

[cgng30]

...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.

[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.

How difficult is it to accurately cut the hole in the hood?

[porschester]

Frankly, unless you are so sure and experienced with what you are doing, I would not adventure into cutting in your porsche rear deck lid, to fit the X51 intake. Make sure someones who has impeccably done that before, performs the work on your car otherwise just stick with the must simplier but uglier Evo intake.

Just my opinion....

I am having my X51 installed as we speak by one of the very best cerified Porsche mechanic... a little more costly...but Id rather be safe than sorry....

Cheers

[neil.schneider]

Frankly, unless you are so sure and experienced with what you are doing, I would not adventure into cutting in your porsche rear deck lid, to fit the X51 intake. Make sure someones who has impeccably done that before, performs the work on your car otherwise just stick with the must simplier but uglier Evo intake.

Just my opinion....

I am having my X51 installed as we speak by one of the very best cerified Porsche mechanic... a little more costly...but Id rather be safe than sorry....

Cheers

So how did it go??

[cgng30]

...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.

it was a bit nerve racking , but i practice in the middle of the cut with a dremel and high speed tungsten carbide bit (then it was no doing back :)) , it took a while to rough cut then i had grind it so i can fit the deck seal. then i hand prime it, and touch paint for rust protection. if you have a will you one can do it,

How difficult is it to accurately cut the hole in the hood?

[ferris]

What about rain? can water easily get into the new hole in the deck?

[frafoss]

The airbox is around $700, the deck seal $10, the inlet hose around $50. I'm also going to add the air mass sensor wire extention as soon as it arrives from Germany. The stock airmass sensor is a direct fit but the stock wiring harness could be a little longer. The only item I have not addressed yet is the oil filler tube. I purchased the X-51 oil filler tube because it's shorter than the stock tube which does not fit up perfectly to the new airbox. The only problem is I can't figure out how to unbolt the stock oil filler tube without dropping the engine. If your hands are smaller maybe it could be accomplished but I can barely fit my hands deep enough to feel the oil filler bolts let alone actually get a socket on them. I'll take some pictures when I get a chance.

Is the air mass sensor wire exetention necessary? To you who has done the installation, can you post a picture of the wire?

[Dave07997S]

The airbox is around $700, the deck seal $10, the inlet hose around $50. I'm also going to add the air mass sensor wire extention as soon as it arrives from Germany. The stock airmass sensor is a direct fit but the stock wiring harness could be a little longer. The only item I have not addressed yet is the oil filler tube. I purchased the X-51 oil filler tube because it's shorter than the stock tube which does not fit up perfectly to the new airbox. The only problem is I can't figure out how to unbolt the stock oil filler tube without dropping the engine. If your hands are smaller maybe it could be accomplished but I can barely fit my hands deep enough to feel the oil filler bolts let alone actually get a socket on them. I'll take some pictures when I get a chance.

Is the air mass sensor wire exetention necessary? To you who has done the installation, can you post a picture of the wire?

I heard that it isn't but it really stretches it pretty taught...I would probably get it.

Dave

[neil.schneider]

I did not extend the wire. It is tight, but fine. If I wanted to make it longer I could separate it a little from the wires it is taped to.

[frafoss]

I did not extend the wire. It is tight, but fine. If I wanted to make it longer I could separate it a little from the wires it is taped to.

Thanks!!

Can you post a picture of your your wire. Would like to see how tight the wire is, before deciding to get a new or not.

[frafoss]

...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.

How do I remove the alternator? Do I need any special tools?

All tips are welcome :)

[neil.schneider]

...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.

How do I remove the alternator? Do I need any special tools?

All tips are welcome :)

Alternator wasn't taken out by my mechanic, he just took off the belt, it moved down a bit and he was able to get his hands in there to do the job.

Edited October 29, 2007 by neil.schneider

[frafoss]

...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.

How do I remove the alternator? Do I need any special tools?

All tips are welcome :)

Alternator wasn't taken out by my mechanic, he just took off the belt, it moved down a bit and he was able to get his hands in there to do the job.

Thanks :)

[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.

How do I remove the alternator? Do I need any special tools?

All tips are welcome :)

Alternator wasn't taken out by my mechanic, he just took off the belt, it moved down a bit and he was able to get his hands in there to do the job.

Did Suncoast supply an adapter to adapt the boot from the X-51 Box to the standard throttle body? It is my understanding the diameters are not only different internally but externally too requiring a sleeve of some type.

[frafoss]

...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.