What intake is everyone running?
#2
12-28-2007, 11:37 PM
The only benefit from a K+N is the fact that it's a NEW filter. Clean stock filters aren't going to rob you of any power. Just clean the stockies...K+Ns are unnecessary and that whole "5hp" claim is a sham
#7
12-29-2007, 11:55 AM
couse were guys and cant leave anything untouched 
but the sound that you get is actually worth the $ itself...power, ehhh i dunno
but the sound that you get is actually worth the $ itself...power, ehhh i dunno
The ONLY purpose of an air filter is to prevent dirt from entering the engine .
The stock filter has one of the highest efficiencies (retaining dirt ) available and is so oversized that under normal driving conditions it does not have to be replaced for ~ 40k miles.
I fail to understand why anyone would spend hundreds of $$ to replace it with an aftermarket air intake with an oiled filter which lets 2 -3 X ( and even more ) dirt pass thru it into the engine .
Not to mention that it has to be washed and re-oiled every few k miles and possibly screws up the MAF
All that to gain 2 or 3 hp (maybe ?)
The stock filter has one of the highest efficiencies (retaining dirt ) available and is so oversized that under normal driving conditions it does not have to be replaced for ~ 40k miles.
I fail to understand why anyone would spend hundreds of $$ to replace it with an aftermarket air intake with an oiled filter which lets 2 -3 X ( and even more ) dirt pass thru it into the engine .
Not to mention that it has to be washed and re-oiled every few k miles and possibly screws up the MAF
All that to gain 2 or 3 hp (maybe ?)
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#8
12-29-2007, 03:47 PM
I love all the bench engineers here 
I don't think I've seen this much hearsay and misinformation in a while.
Saying that the only purpose of an air filter is to prevent dirt from entering the engine is like saying the only purpose of the exhaust is to remove spent combustion gases from the engine compartment--a little too simplistic.
Here's some food for thought:
* The 3.2L Boxster engine make nearly 50HP less than the 3.4L 996 engine, yet it uses the same heads, cams, etc.,. Proportionally, it should be making at least 25HP more.
* The 986 Special Edition makes 6HP more than the non-SE. The SE has the improved 987 intake which uses a much larger air filter and better flow.
* The air filter on a Camry V-6 is bigger than my Boxster, and it makes a lot less HP.
* Have you seen the size of a 996 air filter?
* I've never read of an M96 motor wearing out.
* Two major areas of improvement to the 987 vs. the 986 which account for HP increases are the intake air box and exhaust which are well-known 986 tuning parts.
* You do not have to re-oil K&N and BMC oil filters every few K miles--more like few 10K miles (actually less often than stock, but for peak performance you will probably do more often).
* The Evo intake has great sound (IMHO), but not everybody wants "great" sound. A lot of people also change the muffler for "better" sound. Both stock pieces are complex labyrinths of passages and resonance chambers primarily to quiet the car down.
* If you have a 2.5L, the intake and exhaust are proportionately less restrictive than on Boxster S engines.
* Can you feel the difference between a full tank and a half a tank of gas or 10 degrees of temperature difference? That's about the realistic gains (not manufacturer claims) we're talking here.
I don't think I've seen this much hearsay and misinformation in a while. Saying that the only purpose of an air filter is to prevent dirt from entering the engine is like saying the only purpose of the exhaust is to remove spent combustion gases from the engine compartment--a little too simplistic.
Here's some food for thought:
* The 3.2L Boxster engine make nearly 50HP less than the 3.4L 996 engine, yet it uses the same heads, cams, etc.,. Proportionally, it should be making at least 25HP more.
* The 986 Special Edition makes 6HP more than the non-SE. The SE has the improved 987 intake which uses a much larger air filter and better flow.
* The air filter on a Camry V-6 is bigger than my Boxster, and it makes a lot less HP.
* Have you seen the size of a 996 air filter?
* I've never read of an M96 motor wearing out.
* Two major areas of improvement to the 987 vs. the 986 which account for HP increases are the intake air box and exhaust which are well-known 986 tuning parts.
* You do not have to re-oil K&N and BMC oil filters every few K miles--more like few 10K miles (actually less often than stock, but for peak performance you will probably do more often).
* The Evo intake has great sound (IMHO), but not everybody wants "great" sound. A lot of people also change the muffler for "better" sound. Both stock pieces are complex labyrinths of passages and resonance chambers primarily to quiet the car down.
* If you have a 2.5L, the intake and exhaust are proportionately less restrictive than on Boxster S engines.
* Can you feel the difference between a full tank and a half a tank of gas or 10 degrees of temperature difference? That's about the realistic gains (not manufacturer claims) we're talking here.
#9
12-29-2007, 05:10 PM
Registered User
Join Date: Apr 2005
Location: North Carolina
Posts: 314
Rep Power: 34 
EVO intake. It's been on my car for 5 years with no problems.
Probably little power gain, but the sound is glorious..
Probably little power gain, but the sound is glorious..
#10
12-29-2007, 08:00 PM
* The 986 Special Edition makes 6HP more than the non-SE. The SE has the improved 987 intake which uses a much larger air filter and better flow.
Is the 987 intake system a straight swap for a 986?
* Have you seen the size of a 996 air filter?
That is true but isn't the throttle body slightly bigger as well?
Is the 987 intake system a straight swap for a 986?
* Have you seen the size of a 996 air filter?
That is true but isn't the throttle body slightly bigger as well?
#11
12-29-2007, 10:40 PM
Just a boxster?
Join Date: Jul 2004
Location: Maple Valley WA
Age: 47
Posts: 2,826
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#12
12-29-2007, 10:58 PM
The 987 intake system is not a direct swap into a non-SE 986. There are some significant changes in the piping and manifolds. There are also ECU and wiring/controller dependencies. The SE is not listed in PET, and I have not been able to find a 986 SE to dissect to verify exactly what is going on 
I haven't been able to find out the throttle body diameters on the 996s either (there are a couple). I do know they are different part numbers, but this just could be an orientation difference or bracket/mounting or something. They both use the same intermediate piece (throttle body mount point) but different gaskets. On the other hand, the 996 Twin Turbo uses the same throttle body and gaskets as the 986 (albeit forced induction). I have mapped out much of the 986 intake and believe the throttle body is a small but not significant restriction. S-Car-Go "makes" an enlarged throttle body for Boxsters, but I don't hear a lot of people raving about it. I also don't know if that's only for non-eGas throttle bodies or not. They claim to machine the factory throttle body, but I would find it hard to believe more than a mm or two could be removed. If someone has access to a 996 throttle body, please measure it. The 986 one is about 69mm diameter.
After all that blah-blah, I have spent a considerable amount of time (and money) with the 987 intake tract. The 987 air box, IMHO, is a very nice design--much better than the OEM 986 or Evo air boxes which is probably why you do not see an Evo replacement 987 air box. I can tell you that a 987 air box will not fit a Mk I (pre-face lift) 986. I don't know whether the 986 SE air box is slightly different than a 987 air box (unlikely Porsche would go through this much development) or if the sheet metal bodies of the Mk II or even just the 986 SE are suitably different (more likely). The 987 air box is a very nice design, and I wish I could find someone to "clone" it for the 986 and make suitable modifications/connection pieces to the 986.
I haven't been able to find out the throttle body diameters on the 996s either (there are a couple). I do know they are different part numbers, but this just could be an orientation difference or bracket/mounting or something. They both use the same intermediate piece (throttle body mount point) but different gaskets. On the other hand, the 996 Twin Turbo uses the same throttle body and gaskets as the 986 (albeit forced induction). I have mapped out much of the 986 intake and believe the throttle body is a small but not significant restriction. S-Car-Go "makes" an enlarged throttle body for Boxsters, but I don't hear a lot of people raving about it. I also don't know if that's only for non-eGas throttle bodies or not. They claim to machine the factory throttle body, but I would find it hard to believe more than a mm or two could be removed. If someone has access to a 996 throttle body, please measure it. The 986 one is about 69mm diameter.
After all that blah-blah, I have spent a considerable amount of time (and money) with the 987 intake tract. The 987 air box, IMHO, is a very nice design--much better than the OEM 986 or Evo air boxes which is probably why you do not see an Evo replacement 987 air box. I can tell you that a 987 air box will not fit a Mk I (pre-face lift) 986. I don't know whether the 986 SE air box is slightly different than a 987 air box (unlikely Porsche would go through this much development) or if the sheet metal bodies of the Mk II or even just the 986 SE are suitably different (more likely). The 987 air box is a very nice design, and I wish I could find someone to "clone" it for the 986 and make suitable modifications/connection pieces to the 986.
#13
12-30-2007, 12:59 AM
Join Date: Jul 2005
Location: Chicago
Posts: 2,908
Rep Power: 140 The 987 intake system is not a direct swap into a non-SE 986. There are some significant changes in the piping and manifolds. There are also ECU and wiring/controller dependencies. The SE is not listed in PET, and I have not been able to find a 986 SE to dissect to verify exactly what is going on
I haven't been able to find out the throttle body diameters on the 996s either (there are a couple). I do know they are different part numbers, but this just could be an orientation difference or bracket/mounting or something. They both use the same intermediate piece (throttle body mount point) but different gaskets. On the other hand, the 996 Twin Turbo uses the same throttle body and gaskets as the 986 (albeit forced induction). I have mapped out much of the 986 intake and believe the throttle body is a small but not significant restriction. S-Car-Go "makes" an enlarged throttle body for Boxsters, but I don't hear a lot of people raving about it. I also don't know if that's only for non-eGas throttle bodies or not. They claim to machine the factory throttle body, but I would find it hard to believe more than a mm or two could be removed. If someone has access to a 996 throttle body, please measure it. The 986 one is about 69mm diameter.
After all that blah-blah, I have spent a considerable amount of time (and money) with the 987 intake tract. The 987 air box, IMHO, is a very nice design--much better than the OEM 986 or Evo air boxes which is probably why you do not see an Evo replacement 987 air box. I can tell you that a 987 air box will not fit a Mk I (pre-face lift) 986. I don't know whether the 986 SE air box is slightly different than a 987 air box (unlikely Porsche would go through this much development) or if the sheet metal bodies of the Mk II or even just the 986 SE are suitably different (more likely). The 987 air box is a very nice design, and I wish I could find someone to "clone" it for the 986 and make suitable modifications/connection pieces to the 986.
I haven't been able to find out the throttle body diameters on the 996s either (there are a couple). I do know they are different part numbers, but this just could be an orientation difference or bracket/mounting or something. They both use the same intermediate piece (throttle body mount point) but different gaskets. On the other hand, the 996 Twin Turbo uses the same throttle body and gaskets as the 986 (albeit forced induction). I have mapped out much of the 986 intake and believe the throttle body is a small but not significant restriction. S-Car-Go "makes" an enlarged throttle body for Boxsters, but I don't hear a lot of people raving about it. I also don't know if that's only for non-eGas throttle bodies or not. They claim to machine the factory throttle body, but I would find it hard to believe more than a mm or two could be removed. If someone has access to a 996 throttle body, please measure it. The 986 one is about 69mm diameter.
After all that blah-blah, I have spent a considerable amount of time (and money) with the 987 intake tract. The 987 air box, IMHO, is a very nice design--much better than the OEM 986 or Evo air boxes which is probably why you do not see an Evo replacement 987 air box. I can tell you that a 987 air box will not fit a Mk I (pre-face lift) 986. I don't know whether the 986 SE air box is slightly different than a 987 air box (unlikely Porsche would go through this much development) or if the sheet metal bodies of the Mk II or even just the 986 SE are suitably different (more likely). The 987 air box is a very nice design, and I wish I could find someone to "clone" it for the 986 and make suitable modifications/connection pieces to the 986.
Lots of good info in there.
#15
12-30-2007, 03:12 AM
If you mean of the 987 air box in a 986 SE, it's been a couple years, but I believe this is the right picture. You can see how big the air filter is compared to the standard 986 air filter if you've ever had that one out. It's a flattened cylinder shape that fits down the side of the engine compartment. There is probably 3X the surface area. The air box design is also a straight shot to the outside on the backside of this picture. No labyrinths. In a real 987, there is a baffle plate for noise and/or water rejection. To the left of the picture, the air box tapers down very nicely to the MAF tube. If you look at the contour of the air box, you cannot physically fit anything much bigger in there. It is also a PITA to remove/replace that filter. There is a cover that seals off any hot air in the engine compartment. If you have ever installed an Evo intake yourself, you can imagine how much fun this might be.