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Intake Modification - Mike Troxel's Version

new 3/27/2004

Elsewhere in this section you will find articles on intake/MAF theory, how to remove the restrictive “Saxophone,” the “Porterized intake” solution, and the “Open Cone Filter Variant.” I’ve tried all three and would like to pass along these important lessons and my own variant.

My Dad and I live here in Southern California – he has a ’98 Taurus V8 SHO and, as with most SHO owners, my Dad believes you can never have “enough” horsepower. I’ve inherited his sickness and seem to get dragged into most of these misadventures right along with him. Unfortunately neither of us is what you would call “mechanically inclined,” and we rarely seem to have the right tools for the job, but we do manage to learn some valuable lessons along the way.

In regards to the general theory about improving the stock intake system of any vehicle the simplest explanation I’ve ever read went like this:

Plug your nose and breathe with your mouth through a straw for at least 2 minutes, you can exhale through your whole mouth. Hard, isn't it? That's similar to what the stock air box/filter does to the engine. Now do the same thing with your mouth open. Tada, easier! You may have also noticed that it took less time to get your lungs full of air! That is similar to most air box/filter mods, less work & more air when you need it (aka NOW). -- http://fordx4.corpsie.com

So the general idea seems to be that stock intake systems restrict airflow, presumably for purposes of noise reduction, by moving the intake point out of the engine bay (i.e. the SHO “saxophone”) and adding additional baffling similar to a muffler. So even if you add a K&N panel filter to your SHO’s stock air box with the intent of allowing for higher CFM’s into the intake manifold, the saxophone still causes the engine to work harder to draw in that air (think about that drinking straw), and prevents it from drawing in the air as quickly as it could without the saxophone in place.

So while I agree that the saxophone must go (it’s hard to argue with the straw theory) before you embark on removing your saxophone you should know that there wasn’t really much in the way of baffling inside the one we removed from my Dad’s ’98 SHO. The saxophone tubing is roughly 2.5-3” in diameter, makes some fairly smooth turns, has no baffling anywhere from end to end, only had one short resonator in the middle, and had a couple of cross-drilled holes above the resonator to draw in additional air right before it went through the fender well. All in all not a bad design. But using the straw theory a shorter tube, or no tube, would allow the engine to draw in more air quicker, and with less effort.

With this in mind I found myself following the procedure in Al Primm’s article on “Saxophone/Mousetrap removal.” Almost everything went as Al described, except…..1) the “gold protrusion” that Al refers to next to the battery box is the head of a 1” tall brass vibration mount and to remove it you need a 13-14mm socket that is deeper than standard – what you really need, in addition to the 6.25” drive extension, is a 2” deep 13-14mm “spark plug” socket – that’s what finally did the trick, 2) the whole operation was made easier once I started using a pivoting-head ratchet driver to angle around obstructions, and 3) you don’t actually have to remove the MAF to get enough slack to move the air box out of the way (I also didn’t use a jack stand but I can see how that would’ve made life easier). Now Al’s article goes on to describe how to remove the resonator from the middle of the saxophone assembly, but this seems like a wasted effort. If’ you’ve gotten this far take the whole saxophone out and leave it out – it’s not worth the pain to reinstall it. Al’s article doesn’t explain how to remove the bottom half of the saxophone (which you’ll want to do because it seems like it might vibrate if left in place), but there’s only one bolt holding it in place – you’ll need the 8mm socket for this and a lot of patience because the bolt head is right below the headlamp, the head faces the front of the car, and you need to reach in from below the lower saxophone assembly and unbolt it blind – this was made easier with the pivoting-head ratchet driver.

Now that the saxophone is gone what’s next? Well I tried to convince my Dad to bolt the air box back in place without an inlet tube and leave it at that, but he had already purchased a K&N Cone Filter (E-0940) so we tried the “Open Cone Filter Variant.” There’s a couple issues here to be aware of: 1) there’s no place to properly mount the oxygen sensor when you’re done and this results in a Check Engine light – which in California means you won’t pass your next smog check, 2) drilling the pilot holes into the base of the K&N cone filter resulted in little metal filings dropping inside the filter which I was unable to shake out and I’m fairly certain they ended up getting sucked into the engine, and 3) the MAF turned out to be plastic, not aluminum like the pictures, and we broke off two corners trying to remove those MAF bolts because the nuts were stripped (and because we weren’t using the right tools). The Cone Filter results were phenomenal, throttle response was instantly improved, but it was that persistent CE light that eventually made us put the stock air box back (with a K&N panel filter of course).

That left us with the “Porterized intake” mod, which seems fairly simple and inexpensive, but I wasn’t thrilled with going from three fixed mounting points to only leaving one loose bolt holding the air box in place. Again I suggested leaving the air box as is with the opening exposed to the engine bay and no inlet tube – after all the theory behind the Exposed Cone Filter is that engine bay temperature in a moving vehicle is only 1 degree warmer than ambient air - but my Dad said he would prefer something that looked stock, so we compromised with our own variant: The Troxel Intake Mod.

We took the upper assembly from the original saxophone and made a hacksaw cut 1” below where the intake tube passes through the fender well, just below the bracket with the 8mm bolt that mounts inside the fender well (#4 in the sax drawing) cutting off the resonator section. Then we used some sandpaper to smooth out the edges of the cut and remounted the new shorter intake tube by passing it up through the fender well, re-inserting it into the air box, and putting the 8mm bolt back into bracket #4 inside the fender well. This left us with a solution that kept the air box firmly mounted, required no additional parts, looked stock from the engine bay, and (combined with the K&N panel filter) provided better throttle response with a more aggressive intake note.

Thanks to Mike for putting a different spin on the modification to the intake.


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