I'd been toying with this idea since seeing a Saleen inside the showroom at the dealer ship with the hood raised. While looking at the engine I noticed the "STOP Reusable Filter" sticker on top of the air box. I thought there has to be some value to these types of filters (like a K&N) because the 4.6 in these cars are tweaked for an extra 30 HP. Not from just the filter, probably a tune and better exhaust as well. I noticed the throat of the airbox lid seemed bigger than the V6 too. With a little research that was confirmed (70mm for the V6, 80mm for the GT, or Saleen). With this information, and knowing the V6 airbox is restrictive, I started thinking why not put on a GT airbox lid, install a K&N filter and modify the airbox bottom by opening up the front and fender side for less restrictive airflow around the filter so that it would sort of mimic a CAI heatshield?
Finding a complete GT airbox took about 3 weeks. I had it and the K&N filter delivered for $86. Yesterday afternoon I did the install. I was able to get the V6 intake hose around the larger GT airbox lid with squirt of WD-40 (it's approximately a 1/2" bigger in diameter). Moving the mass air flow sensor over was no problem. Next came the modification to the airbox bottom. I cut out the front panel following the natural shape, leaving about an inch or so along the top edge, and a 1/2" along the two sides, the flat bottom edge and the angled bottom edge. In other words, a five sided cut-out the shape of the front of the airbox. I used 1" and 1-1/2" spade bits to cut strategically placed holes on the fender side. After about 45 minutes I reconnected the battery and started the engine. I noticed at start-up the engine needed a few more revolutions to start, and when it did the idle was somewhat rough for a few seconds, but then evened out. So far, so good. On to the road test.
I took it easy in the neighborhood, got to the first highway and accelerated normally. Hmmm. Felt better, sounded better. Got to the next highway and opended her up at speeds of 30, 40, 50 and 60 mph. Let me say right now that for me life is about managing your expectations. I went for the road test not expecting an earth moving experience, but some improvement was certainly expected. It would have to be better than stock with the increased air volume and flow. There was also the added benefit of some fresh air blowing in to the air box. I hadn't considered this until the installation was completed and pointed a 6" fan at the grill and felt the air hit my hand at the airbox. What I got was more than a pleasant surprise. The car accelerated to speeds of 80 to 90 mph like never before. And it sounded good doing it too. Next came some dead stop, straight on take offs. The first thing I noticed with this drill was that 40% to 50% of the torque lag in first (yeah, I have an auto) was done away with. You could tell the car was on the verge of breaking the tire loose. Next I pulled in to a business closed for the day and pulled out to the right. With the stock intake the car would barely squeal the tire, and that was when you were almost through the turn (again the torque lag). Yesterday, the car laid down a black stripe on the pavement. I couldn't freakin' believe it! Back at home in the driveway I used the brake to see if I could get the tire to break loose. I kid you not, I didn't get the gas pedal more than 1/3 of the way down and the back tire was barking at me. I'm like Holy Crap! Before you could floor it with the brake applied and it would just moan at you until you let off the brake pedal, lag then take off.
Everything sounds good, right? It didn't last. I go in house to get my son to go for a ride (I've got to share this new power with someone), start the car and back out of the garage. At the end of the driveway the idle flutters and then I get (yeah, you guessed it), the dreaded CEL! For the next 1/2 hour I try different configurations of the airbox parts to get rid of the CEL. I end up having to take off the GT airbox lid and putting the stock lid back on. I was however, able to leave the modified airbox bottom and the K&N filter in place with no problems.
Now, I don't have dyno runs to make any claims about horsepower, nor do I know anyone who has this car with a CAI installed, but I can't imagine it being much better than what I experienced yesterday. I could be wrong, and if I am then great. That just means that CAI's provide more of a punch! And I have to say that with the stock airbox and just the K&N filter I felt a small increase in acceleration and throttle response. With the configuration I have now I'd have to say that the performance is about half what it was with the GT airbox lid, K&N filter and modified airbox bottom, which is still noticably better than stock. Not neck-breaking-slam-you-in-the-seat better, but noticably better. The torque lag seems to be about 20% or so reduced. Once I have an X-Cal2 in hand, I'll re-install the GT airbox lid and try again. I think CEL won't be a problem then since the tunes are geared for increased air flow. If so then this could be a good bang-for-the-buck investment. Geez, I'm rattling on here. Forgive me. Just sharing my experience. And keep in mind my comments are subjective, but I've tried to be accurate with my descriptions. If any of you have any ideas about how to keep the CEL off without the X-Cal2, I appreciate any and all input. Thanks.

 

You may be on to something!!!!

You must be pumping more air than me (with a CAI).... i didn't get a code on air flow even before I installed my tune......

Frankly I haven't seen anyone get a code like that..... <<<<<<<<<more air = more power .....(if you can balance the F ratio).....

Good Luck and let us know!!!!

 

A really interesting experiment... if you tune with your X-cal, you might just be onto something! Nice job tinkering!

 

I did something similar with a cone filter from autozone and some parts from home depot...cost about $40 total. It made my check engine light come on, so I took it off and installed an AFE that didn't require a tune.........there was definately a difference between the AFE and my custom one....whish I had held out for an xcal, but now I am just going to bite the bullet and get me a Diablo CAI and tuner in the weeks to come.

 

Did you try disconnecting the battery and then installing the GT airbox lid?

 

BTW Afixer has the GT airbox in his (without all of the mods you have done) and a stock filter (until I give him my K&N).

 

To beaustang:

Yes. The battery was disconnected for the initial install and for each change there after. I did not however, try the GT lid with the stock filter, only with the K&N. To get the full benefit it looks like I'm going to have to spring for the X-Cal2, which I was planning to do anyways. Based on other's experiences the tune should take care of the CEL. Someone please correct me if I'm wrong on this. Preferably before I buy LOL!

 

Very cool! You are probably running pretty lean with all of that extra air coming in. You really need a dyno tune to get it running right. It would be really nice if you could get a back to back dyno with the stock air intake and then the GT. I wouldn't run it lean like that for too long. Not good for your engine!

 

nice job experimenting, but as Jimp said your gonna screw up your engine if i were you i would change it back to stock before i messed up my engine, either that or get a dyno tune.

 

Currently the stock lid is back on with the K&N filter and modified bottom with no problems (read CEL). There is still a noticable gain in performance, but not like it was with the GT lid included in the mix. Ah, the thirst for more power. It will drive a sane man crazy! But I hear the hot chicks like guys on the edge! Sheesh, who am I kidding. For as long as I've been married all I can do is run to the end of my chain and bark!